阅读说明：本技术 复合材料及其制备方法、转动机构和电子设备 (Composite material, preparation method thereof, rotating mechanism and electronic equipment ) 是由 蔡明� 于 2020-05-28 设计创作，主要内容包括：本申请涉及复合材料及其应用技术领域,尤其涉及一种复合材料及其制备方法、转动机构和电子设备。该复合材料,包括层叠设置的基材层和金属基掺杂层；其中,所述基材层的材料为第一钢材料；所述金属基掺杂层的材料包括第二钢材料和碳化物。本申请能够提高材料的耐磨性能,可改善转动机构的长期耐磨性,有助于延长其使用寿命。(The present disclosure relates to composite materials and application technologies thereof, and particularly to a composite material, a method for manufacturing the composite material, a rotating mechanism, and an electronic device. The composite material comprises a base material layer and a metal-based doping layer which are arranged in a laminated manner; the material of the base material layer is a first steel material; the material of the metal-based doped layer includes a second steel material and a carbide. The wear-resisting property of the material can be improved, the long-term wear resistance of the rotating mechanism can be improved, and the service life of the rotating mechanism can be prolonged.)

1. The composite material is characterized by comprising a base material layer and a metal-based doping layer which are arranged in a laminated mode;

the material of the base material layer is a first steel material;

the material of the metal-based doped layer includes a second steel material and a carbide.

2. The composite material according to claim 1, wherein the carbide is selected from one or more mixtures of silicon carbide, tungsten carbide, titanium carbide, niobium carbide, chromium carbide, boron carbide or vanadium carbide.

3. The composite material of claim 1, wherein the carbide is present in an amount not less than 10 volume percent.

4. The composite material of claim 3, wherein the carbide is present in an amount of 10% to 80% by volume.

5. The composite material of claim 1, wherein the carbide has an average grain size of no greater than 10 μm.

6. The composite of any of claims 1-5, wherein the material of the metal-based doped layer further comprises a sulfide.

7. The composite material of claim 6, wherein the sulfide comprises molybdenum sulfide or modified molybdenum sulfide.

8. Composite material according to claim 6 or 7, characterized in that the volume percentage of sulphide is between 5% and 50%.

9. Composite material according to claim 6 or 7, characterized in that the volume percentage of said sulfides is greater than 0 and not greater than 30% and the volume percentage of said carbides is not lower than 10%.

10. Composite material according to any of claims 6-9, characterized in that the average particle size of the sulphide is not more than 10 μm.

11. The composite of any of claims 1-10, wherein the metal-based doped layer has a thickness of not less than 0.05 mm.

12. The composite of claim 11, wherein the metal-based doped layer has a thickness of 0.1mm to 10 mm.

13. The composite material according to any one of claims 1-12, wherein the first steel material is a carbon steel or an alloy steel;

the second steel material is carbon steel or alloy steel;

wherein the alloy steel comprises stainless steel.

14. The composite material according to any one of claims 1-13, characterized in that the average grain size of the first steel material is not more than 30 μ ι η;

and/or the average grain size of the second steel material is not more than 30 μm.

15. A preparation method of a composite material is characterized by comprising the following steps:

forming a green body of a substrate layer, wherein the substrate layer is made of a first steel material;

forming a green body of a metal-based doping layer on the surface of the green body of the substrate layer, wherein the green body of the metal-based doping layer and the green body of the substrate layer are laminated, and the material of the metal-based doping layer comprises a second steel material and carbide;

and sintering and heat-treating the green body of the base material layer and the green body of the metal-based doping layer which are arranged in a laminated manner to obtain the composite material.

16. The method for preparing a composite material according to claim 15, wherein forming a green body of the substrate layer specifically comprises:

providing a first feed containing the first steel material, and performing first powder injection molding by using the first feed to obtain a green body of the substrate layer;

the forming of the green body of the metal-based doping layer on the surface of the green body of the substrate layer specifically includes:

and providing a second feeding material containing the second steel material and the carbide, and performing secondary powder injection molding on the surface of the green body of the substrate layer by adopting the second feeding material to obtain a green body of the metal-based doping layer.

17. The method for preparing a composite material according to claim 15, wherein forming a green body of the substrate layer specifically comprises:

providing powder of the first steel material, and performing primary powder pressing forming by adopting the powder of the first steel material to obtain a green body of the substrate layer;

forming a green body of the metal-based doping layer on the surface of the green body of the substrate layer, specifically comprising:

and providing mixed powder containing the second steel material and the carbide, and performing secondary powder pressing forming on the surface of the green body of the substrate layer by adopting the mixed powder to obtain the green body of the metal-based doping layer.

18. The method for preparing a composite material according to any one of claims 15 to 17, wherein the green body of the substrate layer and the green body of the metal-based doped layer, which are disposed in a stacked manner, are sintered and heat-treated to obtain the composite material, and specifically comprises:

sintering and heat-treating the green body of the base material layer and the green body of the metal-based doping layer which are arranged in a laminated manner to obtain an intermediate-form composite material;

and carrying out hot isostatic pressing treatment on the composite material in the intermediate form to obtain the composite material.

19. A method for the preparation of a composite material according to any one of claims 15 to 18, wherein the sintering temperature is between 1100 ℃ and 1400 ℃ and the holding time is between 2 hours and 3 hours.

20. A method for the preparation of a composite material according to any one of claims 15 to 19, characterized in that said heat treatment comprises a solution treatment at a solution temperature of 1000 ℃ to 1100 ℃ for a time of 1 hour to 3 hours and an aging treatment;

the aging temperature of the aging treatment is 400-500 ℃, and the time is 3-5 hours.

21. The method of any one of claims 15-20, wherein the material of the metal-based doped layer further comprises a sulfide.

22. A rotary mechanism, wherein at least part of the material of the rotary mechanism comprises a composite material as claimed in any one of claims 1 to 14 or a composite material produced by a method as claimed in any one of claims 15 to 21.

23. A rotary mechanism according to claim 22 comprising a cam and/or gear of a material comprising a composite material according to any one of claims 1 to 14 or a composite material produced by a method according to any one of claims 15 to 21.

24. An electronic device characterized by comprising the rotating mechanism of claim 22 or 23.

25. The electronic device of claim 24, wherein the electronic device is a foldable electronic device, the foldable electronic device comprising the rotating mechanism and two body portions, the two body portions being connected by the rotating mechanism.

Technical Field

The present disclosure relates to composite materials and application technologies thereof, and particularly to a composite material, a method for manufacturing the composite material, a rotating mechanism, and an electronic device.

Background

With the continuous evolution and development of electronic equipment, different from a sandwich structure or a box structure of a board straightening machine used on a large scale in the market at present, a flexible folding smart phone becomes a focus of current mobile phone competition as a new mobile phone form, becomes an important branch of the mobile phone field in the future, and has a larger-size screen after being flexibly folded and unfolded, so that a part of tablet personal computers can be replaced. Folding electronic devices (such as folding mobile phones, folder for short) are divided into two types: the inner folding machine is that the screen is inside and can be seen after being unfolded; the folding machine, i.e. the screen, is outside and the screen is still visible in the closed state. Whatever the type of folder, what really functions during the unfolding and closing is a rotating mechanism that links the two or three sections being folded.

The rotating mechanism is used as one of core components of the folding machine, the folding machine normally uses opening and closing operation which is completed by the rotating mechanism, the requirement on the reliability of the rotating mechanism is very high, particularly, relative motion between different parts in the normal opening, closing and closing processes of the rotating mechanism inevitably causes relative friction to generate certain abrasion, the abrasion can weaken the opening, closing and closing resultant force and long-term reliability of the rotating mechanism to a certain extent, and therefore, the abrasion between the parts of the rotating mechanism in the mutual motion process needs to be reduced as little as possible. This places very high demands on the material of certain parts of the rotating mechanism, both in terms of strength and hardness, and is able to produce wear after many times of frictional wear without affecting the performance of the rotating shaft.

However, the materials of the friction wear type parts in the rotating mechanism of the existing electronic device are difficult to meet the current wear-resistant requirements, and the long-term reliability of wear resistance of the parts still needs to be improved.

Therefore, how to improve the long-term wear resistance of the materials of the friction wear type parts in the rotating mechanism becomes a problem to be solved urgently.

Disclosure of Invention

The application aims to provide a composite material, a preparation method thereof, a rotating mechanism and electronic equipment, and long-term wear resistance of the rotating mechanism can be improved.

According to a first aspect of the present application, there is provided a composite material comprising a substrate layer and a metal-based doping layer which are disposed in a stacked manner; wherein the material of the substrate layer is a first steel material; the material of the metal-based doped layer includes a second steel material and a carbide.

The composite material is a layered composite material, and the layered composite material comprises a base material layer and a metal-based doped layer which are arranged in a stacked mode. The material of the substrate layer is a first steel material, the first steel material has certain strength and hardness, the effect of maintaining certain strength and toughness of the composite material can be achieved through the arrangement of the substrate layer, and the effect of guaranteeing the basic service performance of the composite material is achieved. The materials of the metal-based doping layer comprise a second steel material and carbide, a layered structure formed by mixing the second steel material and the carbide is arranged on the surface of the substrate layer in a covering mode, the hardness of the composite material can be enhanced, and the wear resistance is improved.

Alternatively, the composite material may be applied to an electronic device, further applied to a rotating mechanism of an electronic device, further applied to a friction wear type component in a rotating mechanism, for example, may be applied to a cam and/or a gear, i.e., the material of the cam and/or the gear may include the composite material. The composite material can be used for manufacturing friction and wear parts such as cams and/or gears, and the like, and can further enhance the hardness and long-term wear resistance of the material on the basis of not reducing the strength and hardness of the material by arranging the base material layer and the metal-based doping layer coated on the surface of the base material layer, thereby effectively avoiding the phenomenon that the existing friction and wear parts such as cams and/or gears are poor in long-term wear resistance or are easy to break in the wear-resistant motion process due to the reduction of basic performance caused in the improvement process of the material.

Alternatively, the carbide may be in the form of powder or particles. In general, a composite material in which a plurality of types of particles are mixed is often used as a conventional doped composite material. The composite material of the invention adopts the concept of overlapping the carbide particle doped steel material and the material with a multilayer laminated structure, can combine the advantages of particle doping and the multilayer laminated structure, avoids the damage to the basic performance of the base material, is convenient for compounding and forming, and is beneficial to obtaining the laminated composite material meeting the performance requirements.

Alternatively, in order to achieve long-term wear resistance, the metal-based doped layer needs to have a certain thickness, for example, the thickness of the metal-based doped layer is not less than 0.05 mm. If the thickness of the metal-based doped layer is too small, the layered material is too thin, and performance is easily reduced in long-term motion, the effect of improving long-term wear resistance can not be achieved, so that the appropriate thickness of the metal doped layer is beneficial to ensuring the wear resistance of the material, and when the composite material is applied to friction wear type parts in a rotating mechanism, the long-term wear resistance required by folding and opening for 15-25 ten thousand times can be achieved under the thickness.

In one possible implementation, the carbide is selected from one or more mixtures of silicon carbide, tungsten carbide, titanium carbide, niobium carbide, chromium carbide, boron carbide, or vanadium carbide. The specific type of carbide may also be varied to meet the long term wear resistance requirements of the composite material. The carbide may be selected from the above types, but is not limited thereto, and other types having similar properties or characteristics may be used according to the actual situation.

Optionally, the carbide is selected from one or more mixtures of silicon carbide, tungsten carbide or titanium carbide. The metal-based doping layer is formed by mixing silicon carbide, titanium carbide or tungsten carbide and a second steel material, so that the source is wide, the cost is low, the hardness is high, and the long-term wear resistance of the composite material is improved.

In one possible implementation, the volume percentage of the carbide is not less than 10%.

In one possible implementation, the carbide is present in an amount of 10% to 80% by volume.

By controlling the volume percentage content of the carbide within a proper range, the method is beneficial to controlling the wear resistance of the metal-based doped layer, and the composite material has good long-term wear resistance, good mechanical properties and the like.

In one possible implementation, the carbide may be in the form of a powder or granules. Specifically, the powdery or granular carbide has an average particle diameter of not more than 10 μm. Therefore, the cost is reduced, and the bonding force between the metal-based doping layer and the substrate layer is improved.

In one possible implementation, the material of the metal-based doped layer further includes a sulfide. The material of the metal-based doped layer may include a second steel material, a carbide, and a sulfide. Through the addition of carbide and sulfide, the composite material can not only increase the hardness and long-term wear resistance, but also realize the self-lubricating effect, and is more beneficial to improving the long-term wear resistance of the composite material.

In one possible implementation, the sulfide includes molybdenum sulfide or modified molybdenum sulfide. Of course, sulfide can be used in other types under the condition of meeting the requirements of long-term wear resistance, self-lubricating property and the like of the composite material.

In one possible implementation, the volume percentage of the sulfide is 5% to 50%.

In a possible implementation, the volume percentage of the sulfide is greater than 0 and not greater than 30%, and the volume percentage of the carbide is not less than 10%.

By controlling the volume percentage content of the carbide and the sulfide within a proper range, the method is beneficial to controlling the wear resistance and the self-lubricating effect of the metal-based doped layer, and the composite material has good long-term wear resistance, good mechanical properties and the like.

In one possible implementation, the carbide may be in the form of a powder or granules. Specifically, the average particle diameter of the sulfide is not more than 10 μm. Therefore, the cost is reduced, and the bonding force between the metal-based doping layer and the substrate layer is improved.

In one possible implementation, the thickness of the metal-based doped layer is not less than 0.05 mm.

In one possible implementation, the metal-based doped layer has a thickness of 0.1mm to 10 mm. By controlling the thickness of the metal-based doped layer within a proper range, the wear-resisting property of the material is ensured, and the cost can be reduced.

In one possible implementation, the first steel material is carbon steel or alloy steel; the second steel material is carbon steel or alloy steel; wherein the alloy steel comprises stainless steel.

In one possible implementation, the first and second steel materials may be in the form of a powder or granules. Specifically, the average grain size of the first steel material is not more than 30 μm; and/or the average grain size of the second steel material is not more than 30 μm.

According to a second aspect of the present application, there is provided a method of preparing a composite material comprising the steps of: forming a green body of a substrate layer, wherein the substrate layer is made of a first steel material; forming a metal-based doped layer green body on the surface of the substrate layer green body, wherein the metal-based doped layer green body is laminated with the substrate layer green body, and the metal-based doped layer material comprises a second steel material and a carbide; and sintering and heat treating the green body of the base material layer and the green body of the metal-based doping layer which are arranged in a laminated manner to obtain the composite material.

As explained in relation to the composite material according to the first aspect, the method for preparing the composite material is based on the same inventive concept as the composite material, and thus has at least all the features and advantages as described in relation to the composite material, and the composite material obtained by the method for preparing the composite material can achieve the effect of effectively improving the long-term wear resistance of the composite material, and will not be described in detail herein.

Specifically, in the preparation process of the composite material, a method of powder injection molding layer by layer for multiple times can be adopted, and a method of powder compression molding layer by layer for multiple times can also be adopted.

In one possible implementation, the green body forming the substrate layer specifically includes: and providing a first feeding containing the first steel material, and performing primary powder injection molding by adopting the first feeding to obtain a green body of the substrate layer.

The green body for forming the metal-based doping layer on the surface of the green body of the substrate layer specifically includes: and providing a second feeding material comprising the second steel material and the carbide, and performing secondary powder injection molding on the surface of the green body of the substrate layer by adopting the second feeding material to obtain a green body of the metal-based doping layer.

Then, the green body of the substrate layer and the green body of the metal-based doping layer which are arranged in a stacked manner are sintered and heat-treated, so that the composite material can be obtained.

In one possible implementation, the temperature of the sintering is between 1100 ℃ and 1400 ℃ and the holding time is between 2 hours (hour, h) and 3 hours. Note that, herein, for convenience of description, the following hours are denoted by h.

In one possible implementation mode, the heat treatment comprises solution treatment and aging treatment, wherein the solution temperature of the solution treatment is 1000-1100 ℃, and the time is 1-3 h; the aging temperature of the aging treatment is 400-500 ℃, and the time is 3-5 h.

In another possible implementation, the green body forming the substrate layer specifically includes: and providing powder of the first steel material, and performing primary powder pressing molding by using the powder of the first steel material to obtain a green body of the substrate layer.

The green body for forming the metal-based doping layer on the surface of the green body of the substrate layer specifically includes: and providing mixed powder containing the second steel material and the carbide, and performing secondary powder press molding on the surface of the green body of the substrate layer by adopting the mixed powder to obtain a green body of the metal-based doping layer.

Then, the green body of the substrate layer and the green body of the metal-based doping layer which are arranged in a stacked manner are sintered and heat-treated, so that the composite material can be obtained.

In one possible implementation mode, the sintering temperature is 1100-1400 ℃, and the holding time is 2-3 h.

In one possible implementation mode, the heat treatment comprises solution treatment and aging treatment, wherein the solution temperature of the solution treatment is 1000-1100 ℃, and the time is 1-3 h; the aging temperature of the aging treatment is 400-500 ℃, and the time is 3-5 h.

In a possible implementation manner, the sintering and heat treatment are performed on the green body of the substrate layer and the green body of the metal-based doped layer which are arranged in a stacked manner, so as to obtain the composite material, and the composite material specifically comprises: sintering and heat-treating the green body of the base material layer and the green body of the metal-based doping layer which are arranged in a laminated manner to obtain an intermediate-form composite material; and carrying out hot isostatic pressing treatment on the composite material in the intermediate form to obtain the composite material.

In one possible implementation, the material of the metal-based doped layer further includes a sulfide.

According to a third aspect of the present application, there is provided a rotating mechanism, at least part of the material of which comprises the above-mentioned composite material, or the composite material produced by the above-mentioned method.

In a possible implementation, the rotating mechanism comprises a cam and/or a gear, and the material of the cam and/or the gear comprises the composite material or the composite material prepared by the method.

According to a fourth aspect of the present application, there is provided an electronic apparatus including the above-described rotating mechanism.

As explained in the foregoing first aspect with respect to the composite material and the second aspect with respect to the method for producing the composite material, the rotating mechanism and the electronic apparatus including the rotating mechanism are based on the same inventive concept as the foregoing composite material and the method for producing the same, and thus have at least all the features and advantages described in the foregoing composite material and the method for producing the same, and the rotating mechanism and the electronic apparatus including the rotating mechanism can achieve the effect of effectively improving the long-term wear resistance, and will not be described in detail herein.

In one possible implementation manner, the electronic device is a folding electronic device, and the folding electronic device includes the above-mentioned rotating mechanism and two main body portions, and the two main body portions are connected through the rotating mechanism.

The technical scheme provided by the application can achieve the following beneficial effects:

the composite material is a layered composite material, and the layered composite material comprises a base material layer and a metal-based doping layer which is arranged on the surface of the base material layer in a covering mode. The material of the substrate layer is a first steel material, the first steel material has certain strength and hardness, the effect of maintaining certain strength and toughness of the composite material can be achieved through the arrangement of the substrate layer, and the effect of guaranteeing the basic service performance of the composite material is achieved. The material of the metal-based doping layer comprises a second steel material and carbide, and a layered structure formed by mixing the second steel material and the carbide is covered on the surface of the substrate layer, so that the effects of enhancing the hardness of the composite material and improving the wear resistance can be achieved. On one hand, if only the base material layer is arranged, although the basic service performance of the material can be ensured, the long-term wear resistance is not good; on the other hand, if only the metal-based doped layer is provided, although the wear resistance can be improved, the obtained material is brittle, insufficient in toughness, and easily broken.

Therefore, the layered composite material can further enhance the hardness and long-term wear resistance of the composite material on the basis of not reducing the strength and hardness of the base material layer or the composite material by doping the carbide and the steel material and by superposing the layered materials with different structures or properties, such as the base material layer and the metal-based doping layer, thereby achieving the effect of effectively improving the long-term wear resistance of the composite material.

Therefore, the rotating mechanism and the electronic device comprising the composite material of the present application have at least the same advantages as the composite material described above, and are not described in detail herein.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the application.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings needed to be used in the embodiments of the present application will be briefly described below, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.

Fig. 1 is a schematic structural diagram of an electronic device in the prior art;

FIG. 2(a) is a schematic view of a flexible folding handset in an ideal state;

fig. 2(b) is a schematic view of a flexible folding handset in an intermediate state;

fig. 2(c) is a schematic view of a flexible folding handset in a final state;

fig. 3 is a schematic structural diagram of a rotating mechanism in a flexible folding mobile phone in the prior art;

FIG. 4 is a schematic illustration of a gear structure in a prior art turning gear;

FIG. 5 is a schematic view of a cam structure in a prior art rotary mechanism;

FIG. 6 is a schematic diagram of the breakage of the components of the rotating mechanism after carburization in the prior art;

FIG. 7 is a schematic illustration of a composite material provided in accordance with an exemplary embodiment of the present application;

FIG. 8 is a schematic view of a metal-based doped layer structure in a composite material according to an exemplary embodiment of the present disclosure;

FIG. 9 is a schematic diagram of a structure of a metal-based doped layer in a composite material according to another exemplary embodiment of the present disclosure;

FIG. 10 is a schematic flow chart of a powder injection molding process for producing a composite material according to an exemplary embodiment of the present disclosure;

fig. 11 is a schematic flow chart of a composite material prepared by powder compaction according to an exemplary embodiment of the present disclosure.

Wherein the reference numerals are as follows:

1-a body portion; 2-a rotation mechanism; 3-a flexible display screen; 301-a bend; 302-a stationary part;

100-a composite material; 101-a substrate layer; 102-a metal-based doped layer;

201-a second steel material; 202-carbide; 203-sulfide.

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and together with the description, serve to explain the principles of the application.

Detailed Description

For better understanding of the technical solutions of the present application, the following detailed descriptions of the embodiments of the present application are provided with reference to the accompanying drawings. It should be understood that the embodiments described are only a few embodiments of the present application, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

Unless defined or indicated otherwise, technical and scientific terms used herein have the same meaning as is familiar to those skilled in the art.

[ electronic apparatus ]

In order to facilitate understanding of the composite material provided in the embodiments of the present application, an application scenario of the composite material is first described below, and the composite material may be applied to an electronic device, for example, a foldable electronic device (mobile terminal). Specifically, the electronic device may include, but is not limited to, a foldable cell phone, a tablet, a notebook, a car computer, a foldable display screen device (e.g., a television), a wearable device, a Personal Digital Assistant (PDA), and the like. In addition, the electronic device of the present application is not limited to the above-described device, but may include a newly developed electronic device. The embodiment of the present application is not particularly limited to the specific form of the electronic device.

Illustratively, as shown in fig. 1, the electronic device may be a folding electronic device, such as a flexible folding handset, including an inner folding machine, an outer folding machine, a triple folding machine, and the like.

The flexible folding mobile phone can comprise a rotating mechanism 2 (also called as a rotating shaft mechanism or a rotating shaft), two main body parts 1 and a flexible display screen, wherein the two main body parts 1 can comprise a first shell and a second shell which are connected through the rotating mechanism 2, and the first shell and the second shell can relatively rotate by utilizing the rotating mechanism 2, so that the folding and the unfolding of the folding mobile phone are realized. The middle bent part of the flexible folding mobile phone shown in fig. 1 needs to be normally opened and closed by using the rotating shaft mechanism 2, that is, the folding and unfolding of the folding mobile phone can be realized by using the rotating mechanism 2.

The structure illustrated in the embodiment of the present application does not specifically limit the foldable mobile phone. In other embodiments of the present application, the handset may include more or fewer components than shown, or combine certain components, or split certain components, or a different arrangement of components. For example, the mobile phone may further include a camera or the like.

Further, as shown in fig. 2(c), the flexible foldable mobile phone may include a rotating mechanism 2, two main body portions 1 and a flexible display 3, where the two main body portions 1 may be housings, such as a first housing and a second housing, the two main body portions 1 are connected through the rotating mechanism 2, the flexible display 3 may include two fixing portions 302 and a bending portion 301, the two fixing portions 302 may be respectively fixedly connected with the two main body portions 1, and the bending portion 301 may be disposed opposite to the rotating mechanism 2. The rotating mechanism 2 shown in fig. 2(c) is a very schematic diagram of the rotating mechanism.

Please continue to refer to fig. 2, which is a schematic diagram of the application and development of the rotating mechanism. Fig. 2(a) shows that in an ideal situation, the flexible display 3 is free to bend without any constraints. Fig. 2(b) shows that in the intermediate state, the non-bending portion of the flexible display 3, i.e. the fixing portion of the flexible display 3 is fixed to the structural member such as the main body portion 1 by bonding, while the bending portion (bending region) of the flexible display 3 is free from constraint, and is bent from the structural member of the flexible display 3 itself, which is similar to the ideal state. Fig. 2(c) shows that in the final state, the non-bending part of the flexible display screen 3, namely two fixing parts 302, are respectively bonded and fixed with the main body part 1, the bending part 301 of the flexible display screen 3 is connected with the rotating mechanism 2, so that the bending and stretching functions are realized, the rotating mechanism 2 can actively match the flexible display screen to change the length of the flexible display screen, the bending state of the flexible display screen can be simulated, and the strength supporting and appearance shielding effects can be achieved.

Further schematic illustrations of the turning mechanism can be seen in fig. 3, for example. The rotating mechanism can be approximately in a symmetrical left part and a right part, the left part and the right part can rotate around a middle guide shaft, and the left part and the right part can be coupled together in a sliding mode between the sliding block and the rotating part when rotating. And a connecting line with a certain length L between the two sliding blocks is kept constant, and the position of the connecting line can be correspondingly superposed with the position of the flexible display screen. Therefore, after the structural part in the main body part is fixedly connected with the sliding part, the rotating part can be in sliding fit with the main body part, the total length of the foldable electronic equipment in the rotating and folding process can be unchanged, and the flexible display screen cannot bear the driving force required by the sliding of the rotating shaft.

It should be noted that the rotating mechanism illustrated in fig. 2 and fig. 3 in the embodiment of the present application is merely an illustration, and does not constitute a specific limitation to the rotating mechanism, the rotating mechanism 2 may be a rotating shaft commonly used in a known foldable mobile phone, and the present application does not make a specific limitation to the structure and the connection relationship thereof, so the structure thereof is not described in detail herein. Also, the present application is not particularly limited with respect to the specific structure, connection relationship, material, or the like of the two main body portions, the flexible display, and the like, and thus will not be described in detail herein.

Those skilled in the art understand that, in order to provide the required functions for the user, the electronic device may include several devices arranged inside the device, which is not particularly limited in this application, and those skilled in the art may adjust the position or specific structure of each device according to the actual requirement.

[ rotating mechanism ]

From the above, the rotating mechanism plays an important role in folding the mobile phone, and the folding and unfolding of the folding mobile phone in normal use need to be completed by depending on the rotating mechanism. However, generally speaking, the structure of the rotating mechanism is complex, the number of parts can be from thirty to thousands, the rotating mechanism not only needs to perform the opening and closing functions, but also needs to support a part of the screen, and is not allowed to loosen to a certain extent, which requires a certain function of preventing the rotating shaft from loosening due to normal opening and closing.

The complex structure of the rotating mechanism makes it include more relative motion friction pairs, such as gear and gear, cam and cam, etc., that is, relative friction wear between gears, or friction wear between cam and cam, or friction wear between cam and other parts. Some of the motion friction pairs belong to surface contact, some of the motion friction pairs belong to line contact, and some of the motion friction pairs belong to point contact, and the contact forms have stronger relevance to the structural design of the rotating shaft, the manufacturing precision of parts, the assembly precision of the rotating shaft and the like. This requires a very high level of gear material and cam material, and requires both a certain strength and a very high hardness, and can withstand several hundred thousand or several hundred thousand times (for example, 15 to 25 ten thousand times) of frictional wear without causing wear that affects the performance of the rotating shaft.

The shape of the gear can be as shown in fig. 4, and the tooth surface in the gear is a relative motion friction surface, so that the requirement on the material of the tooth surface is at least high. The shape of the cam can be as shown in fig. 5, and the irregular arc surface in the cam is a relative motion friction surface, so that the requirement on at least the material of the irregular arc surface is high.

In the prior art, the materials of gears and cams are mainly steel materials, especially stainless steel materials, and in order to save cost, the Metal powder Injection Molding (MIM) process is mainly selected at present. The Vickers hardness of the stainless steel materials is above 300HV, however, the stainless steel materials are only directly used, so that the current wear resistance requirements are difficult to meet, and meanwhile, the wear resistance also needs to have certain lubricating performance and cannot be met, which becomes a main problem of friction wear parts in the current rotating shaft. Specifically, the materials of the frictional wear-type components in the conventional rotating mechanism are mainly described in detail below by taking the materials of the gears and the cams in the rotating mechanism as an example, and it should be understood that other related frictional wear-type components have the same or similar problems.

In the prior art, the processing methods of stainless steel materials of cams and gears mainly include carburizing treatment, Physical Vapor Deposition (PVD) treatment, and a combination treatment of carburizing treatment and PVD treatment. In particular:

(1) at present, MIM 420 stainless steel and MIM 17-4 stainless steel are the main materials used for a rotating shaft gear and a cam of a folder, and in practical use, the materials need to be hardened in a mode of adopting a carburizing process mostly, particularly low-temperature plasma carburizing, but the lowest temperature is about 400 ℃. Among them, plasma carburizing is a third carburizing method which is adopted after gas carburizing and vacuum carburizing. The treatment process is carried out under the pressure of 100-1000Pa, and the high-voltage pulse power supply ionizes the atmosphere containing carbon to form ions to bombard the surface of the product to achieve the carburization effect; thereby effectively controlling the hardened layer and reducing the deformation.

A part of stainless steel material was selected to be carburized, and hardness of the carburized material was as shown in Table 1.

TABLE 1 carburizing treatment

As can be seen from Table 1, after carburization, the hardness of most materials can reach over 900HV, which is greatly improved compared with the hardness of 300HV of the original stainless steel.

However, although some stainless steel materials after carburization can improve hardness values, carburization still belongs to a high-temperature process, and in any form of carburization, the properties of a matrix, particularly the strength and hardness of the matrix, may be greatly influenced, and the normal use of parts is finally influenced.

And selecting a part of stainless steel materials again to perform sintering, carburizing, heat treatment, combination and the like, and performing the Rockwell hardness test on a SUS (Steel Use stainless)420 sample. The result shows that the hardness and the strength performance of the stainless steel substrate are reduced due to the high-temperature carburization process, the multiple-cycle opening and closing test cannot be met, and the specific test result is shown in table 2.

TABLE 2 Rockwell Hardness of SUS 420 specimen (Rockwell Hardness, HRC)

As can be seen from table 2, the average hardness HRC of the heat treatment, heat treatment + carburization 1, and heat treatment + carburization 2 (thickness) decreased in order, indicating that the performance decreased continuously. This indicates that the bulk hardness of the material decreases to some extent after carburization.

In addition, as shown in fig. 6, practical application results show that the carburized stainless steel cam causes the cam to break during normal wear-resistant movement, the cause of the breakage may be the influence of the heating process of carburization on the strength of the base body, and the strength reduction causes serious reduction of long-term reliability.

(2) In the prior art, for the stainless steel, PVD hardening treatment is performed, for example, Diamond Like Carbon (DLC) film treatment, which has a certain wear resistance. Furthermore, DLC is often used for wear resistance of tool and mould surfaces with very good results.

Although the Vickers hardness value of DLC is higher, generally above 1300HV, the hardness is far higher than that of the base material of MIM stainless steel. However, the DLC film is thin, generally less than 3 μm, and is difficult to satisfy 15-25 ten thousand long-term mutual motion abrasion, and cannot completely satisfy the current requirements.

(3) The carburization treatment and the DLC film layer treatment are combined, the stainless steel is firstly carburized, and then the DLC treatment is carried out, so that the comprehensive wear resistance of the material is improved to a certain extent. However, even if the two schemes are combined, the problems of weakening the influence of carburization on the hardness and strength of the base material, common long-term reliability of the thinner DLC and the like still exist, and the market demand for rapid development is difficult to meet.

As can be seen, MIM stainless steel has a low bulk hardness and a vickers hardness of 300HV or more, and therefore needs to be treated. The temperature rise and temperature reduction process of carburization has certain weakening effect on the strength and hardness of the MIM stainless steel body; the hardness of the DLC film layer is high, but the film layer is too thin to realize the wear resistance of tens of thousands of relative movements; at present, all MIM stainless steel and surface treatment modes thereof are difficult to realize wear resistance of relative movement for tens of thousands of times, and are difficult to realize self-lubrication at present. Although conventional DLC has a certain lubricating effect, the DLC film layer has a thinner actual DLC component, and thus it is difficult to actually and effectively function.

Therefore, how to realize the material of the friction wear type parts in the rotating mechanism, such as gears and cams, for example, the MIM stainless steel material can increase the hardness and improve the long-term wear resistance without reducing the strength and hardness of the material, and is a problem to be solved at present. In addition, if a material which can increase the hardness and the long-term wear resistance and can realize the self-lubricating effect can be provided, the material has higher application value and market prospect, and the application prospect is wider. If the hardness and the long-term wear resistance can be increased and the self-lubricating effect can be realized, the surface layers of the gears and the cams made of the MIM stainless steel need to have thicker ultrahigh-hardness layers and have a certain self-lubricating effect.

Based on this, in order to overcome the deficiencies of the prior art, the technical solution of the embodiments of the present application provides a composite material, which can be used for a rotating mechanism in a folding electronic device, and further can be used for friction wear type parts such as gears, cams, and the like in the rotating mechanism. The friction and wear parts such as gears, cams and the like which adopt the composite material can realize the effects of higher hardness and better long-term wear resistance, and can realize the long-term wear resistance required by folding and opening at least 15-25 ten thousand times.

[ composite Material ]

In some embodiments, the composite material will be described in detail below with reference to specific embodiments and accompanying drawings.

Referring to fig. 7-9, embodiments of the present disclosure provide a composite material, in which the composite material 100 is a laminated composite material and has a multi-layer structure, that is, the composite material 100 may be formed by laminating two or more layers. Specifically, the composite material 100 may include a base material layer 101 and a metal-based doping layer 102 that are stacked; that is, the substrate layer 101 and the metal-based doping layer 102 are both of a layered structure, and the substrate layer 101 and the metal-based doping layer 102 are bonded or disposed in a laminated manner.

The material of the substrate layer 101 may be a first steel material;

the material of metal-based doped layer 102 may include a second steel material 201 and a carbide 202.

It is understood that the metal-based doped layer 102 is a layered structure formed by mainly combining a metal material and a doped material. The metal material may be a second steel material, the doped material may be an inorganic material capable of increasing the wear resistance of the material, and further, the doped material may be carbide.

In the layered composite material, the metal-based doping layer may be a surface layer, and the base material layer may be referred to as a base layer. This stratiform combined material passes through the compound setting of metal base doping layer and substrate layer, and wherein the substrate layer can play the effect of maintaining certain intensity and toughness, can guarantee combined material's basic performance, contains the carbide that hardness is higher in the metal base doping layer, can strengthen material's hardness, can play the effect that improves the wearability, and the metal base doping layer has certain thickness, can ensure long-term wear resistance. On one hand, if only the base material layer is arranged, although the basic service performance of the material can be ensured, the long-term wear resistance is not good; on the other hand, if only the metal-based doped layer is provided, although the wear resistance can be improved, the obtained material is brittle, insufficient in toughness, and easily broken. Therefore, through the addition of carbide and the matched arrangement of layered materials with different structures or properties, such as a metal-based doped layer and a substrate layer, the long-term wear-resisting property required by folding and opening for at least 15-25 ten thousand times can be realized.

Therefore, compared with the existing stainless steel material treated by the treatment processes such as carburization and the like, the composite material provided by the embodiment of the application can be widely applied to friction and wear parts such as gears, cams and the like in a rotating mechanism, can realize the long-term wear resistance required by folding and opening for at least 15-25 ten thousand times, can relieve the problems of poor long-term wear resistance, influence on service performance and the like of the existing parts, and is beneficial to prolonging the service life of the friction and wear parts such as the gears, the cams and the like.

In the metal-based doped layer, the carbide generally has the characteristics of high hardness, high melting point, high temperature resistance, stable chemical property and the like, and can be used as an excellent abrasive. The specific type of carbide may also be varied to meet the long term wear resistance requirements of the composite material. Specifically, in some embodiments, the carbide may be selected from one or more mixtures of silicon carbide, titanium carbide, tungsten carbide, tantalum carbide, niobium carbide, chromium carbide, boron carbide, or vanadium carbide. Illustratively, the carbide may be silicon carbide, may be titanium carbide, may be tungsten carbide, may be tantalum carbide, may be niobium carbide, may be chromium carbide, may be boron carbide, may be vanadium carbide, may be a mixture of silicon carbide and titanium carbide in any proportion, may be a mixture of silicon carbide, titanium carbide and tungsten carbide in any proportion, may be a mixture of titanium carbide, niobium carbide and chromium carbide in any proportion, and the like.

It should be understood that the specific type of carbide is not limited to the above listed ones, and other types of carbide, such as modified materials of the above mentioned carbides, or other types of carbide, etc., may be used in the case of satisfying the long-term wear resistance requirements of the composite material.

When the carbide includes a mixture formed by mixing a plurality of components such as silicon carbide, titanium carbide, tungsten carbide, tantalum carbide and the like, the components can be mixed according to any proportion; that is, when the carbide includes a mixture of two or more kinds, the specific ratio or content of each component is not particularly limited and can be adjusted by those skilled in the art according to actual conditions.

In some embodiments, the carbide is preferably silicon carbide (SiC), titanium carbide (TiC), or tungsten carbide (WC). The metal-based doping layer is formed by mixing silicon carbide, titanium carbide or tungsten carbide and a second steel material, so that the source is wide, the cost is low, the hardness is high, and the long-term wear resistance of the composite material is improved.

The doping level of the carbides in the metal-based doped layer needs to be in a suitable range in order to achieve long-term wear resistance. Specifically, in some embodiments, the volume percent of the carbide is not less than 10%, i.e., the volume percent of the carbide doping is 10% or more and 100% or less.

It is noted that, herein, unless otherwise stated, percentages, ratios or parts referred to are by volume. For example, the content of carbides refers to the volume percentage content of carbides, which may also be referred to as the volume percentage content of carbides, which may be 10-80%, may also be expressed as 10-80 vol.%, or may be expressed as 10-80 vol.%. For convenience of description, the following is mainly expressed in 10-80%.

In addition, the percentages referred to (including volume percentages) are based on the total volume of the composition, if not otherwise specified. For example, the metal-based doped layer may contain carbides in an amount greater than or equal to 10% and less than 100% by volume, based on the total volume of the doped layer.

In some embodiments, the carbide is present in an amount of 10 to 80 volume percent, further 20 to 70 volume percent, further 30 to 60 volume percent, further 40 to 50 volume percent; typically, but not by way of limitation, the volume percent content of carbides may be, for example, 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, and any value in the range of any two of these points.

By controlling the volume percentage content of the carbide within a proper range, the method is beneficial to controlling the wear resistance of the metal-based doped layer, and the composite material has good long-term wear resistance, good mechanical properties and the like.

In some embodiments, the carbide may be in the form of a powder or granules. Accordingly, the first steel material and the second steel material may be in the form of powder or granules. The form of the first steel material and the second steel material is not limited to this, and may be, for example, a wire rod.

It will be appreciated that the doping pattern of the metal-based doped layer is preferably particle doped, i.e. the metal-based doped layer may be a layered composite of carbide particles doped with the second steel material. Therefore, the composite material is convenient to compound and form, and is beneficial to obtaining the layered composite material meeting the performance requirement.

The carbide particle size (grain size) in the metal-based doped layer needs to be in a suitable range in order to achieve long-term wear resistance or to meet the process requirements of the fabrication process. In some embodiments, the carbides have an average grain size no greater than 10 μm (≦ 10 μm), and the carbides may have an average grain size on the micro-scale or nano-scale. Illustratively, the average particle size of the carbide may be, for example, 1nm to 10 μm, 5nm to 10 μm, 10nm to 10 μm, 100nm to 10 μm, 10nm to 8 μm, 100nm to 5 μm, or the like. The specific value of the average grain size of the carbide can be selected and set according to the actual process requirements, and is not limited too much.

By adopting the granular carbide with proper grain size, the cost can be reduced, and the bonding force between the metal-based doping layer and the substrate layer can be promoted. On one hand, if the particle size of the particles is too small, the cost of milling is high; on the other hand, if the particle size of the particles is too large, the strength of the doped layer is reduced, and in order to meet the binding force between the layered structures, the required process conditions are harsh, and the process cost is high.

In order to make the composite material capable of increasing hardness and long-term wear resistance and realizing self-lubricating effect, a doping material with certain self-lubricating effect, such as sulfide, needs to be doped in the metal-based doping layer. Specifically, referring to fig. 8, in some embodiments, the material of metal-based doped layer 102 further comprises sulfide 203; that is, the material of metal-based doped layer 102 may include second steel material 201, carbide 202, and sulfide 203. The carbide 202 has high hardness, which is helpful for improving the wear resistance of the composite material, and the sulfide 203 is a good lubricating material, which can play a self-lubricating role.

Therefore, the layered composite material provided by the embodiment of the invention mainly comprises the metal-based doping layer (surface layer) and the base material layer (base layer), wherein the base layer can play a role in maintaining certain strength and toughness, the surface layer can play a role in wear resistance and self lubrication, the surface layer has a certain thickness, and the long-term wear resistance required by folding and opening for at least 15-25 ten thousand times can be realized at the thickness. Further, in which the doped material of the surface layer is mainly composed of a carbide having high hardness such as silicon carbide or the like and a sulfide having high lubricity such as molybdenum sulfide, the two particulate materials are doped in a base steel material such as a stainless steel material, thereby forming a stainless steel-based particle-doped composite material to obtain a metal-based doped layer. The metal-based doped layer is combined with a substrate layer, such as a stainless steel layer, to form a layered composite material having excellent long-term wear resistance.

In the metal-based doped layer, sulfide has the characteristics of good dispersibility, no adhesion, oxidation resistance, suitability for mechanical working conditions of high temperature, high pressure, high rotating speed and high load, capability of prolonging the service life and the like. The specific type of sulfide can also be varied while meeting the requirements of long-term wear resistance, self-lubricity, etc. of the composite material. Specifically, in some embodiments, the sulfide includes molybdenum sulfide (which may also be referred to as molybdenum disulfide) or a modified molybdenum sulfide.

The modified molybdenum sulfide is a material obtained by using molybdenum sulfide as a base material and enhancing or improving certain properties of the molybdenum sulfide by various physical or chemical methods. For example, the modified molybdenum sulfide may be modified with a metal, and the metal may be selected from metal materials such as nickel, manganese, cobalt, and the like. On the basis of not influencing the self-lubricating property of molybdenum sulfide, the embodiment of the present application does not limit the specific modification mode of the modified molybdenum sulfide, and can be selected and set by those skilled in the art according to the actual situation. Further, commercially available products can be used for both of the molybdenum sulfide and the modified molybdenum sulfide.

Illustratively, the sulfide may be molybdenum sulfide. The molybdenum sulfide is used as an important solid lubricant, can be used as a lubricant for various parts, and can play a role in lubrication, wear resistance and friction reduction.

It is to be understood that the specific type of the sulfide is not limited to the above-listed ones, and that other types of the sulfide may be used in the case of satisfying the requirements of the long-term wear resistance, self-lubricity, etc. of the composite material.

In order to achieve better self-lubricating property and long-term wear resistance, the doping amount of sulfide in the metal-based doping layer needs to be in a proper range. Specifically, in some embodiments, the volume percent of the sulfide compound is 5-50%. It is understood that the total volume percentage of sulfide, carbide, and second steel material in the metal-based doped layer needs to be less than or equal to 100%.

In some embodiments, where the material of the metal-based doped layer comprises the second steel material, the carbide, and the sulfide may be present in an amount of 5-50% by volume, further in an amount of 5-30% by volume, further in an amount of 10-30% by volume; the volume percentage content of the carbide is not less than 10%, further 10-80%, further 20-70%, further 30-60%, further 40-50%; the balance may be the second steel material.

In some embodiments, the volume percent sulfide may be 5-50%, and typically, but not by way of limitation, the volume percent sulfide may be, for example, 5%, 10%, 20%, 30%, 40%, 50%, and any value in the range of any two of these values.

By controlling the volume percentage content of the carbide and the sulfide within a proper range, the method is beneficial to controlling the wear resistance and the self-lubricating effect of the metal-based doped layer, and the composite material has good long-term wear resistance, good mechanical properties and the like.

In some embodiments, the sulfide may be in the form of a powder or granules. That is, the form of both the carbide and the sulfide is preferably powdery or granular.

The particle size (grain size) of the sulfide in the metal-based doped layer needs to be in a suitable range in order to achieve long-term wear resistance or to meet the process requirements of the fabrication process. In some embodiments, the average particle size of the sulfide is no greater than 10 μm (< 10 μm), and the average particle size of the sulfide can be micron-sized or nanometer-sized. Illustratively, the average particle size of the sulfide may be, for example, 1nm to 10 μm, 5nm to 10 μm, 10nm to 10 μm, 100nm to 10 μm, 10nm to 8 μm, 100nm to 5 μm, or the like. The specific value of the average particle size of the sulfide can be selected and set according to the actual process requirements, and is not limited too much.

By adopting the granular sulfide with proper grain size, the cost can be reduced, and the bonding force between the metal-based doping layer and the substrate layer can be promoted. On one hand, if the particle size of the particles is too small, the cost of milling is high; on the other hand, if the particle size of the particles is too large, the strength of the doped layer is reduced, and in order to meet the binding force between the layered structures, the required process conditions are harsh, and the process cost is high.

In order to achieve long-term wear resistance, the metal doped layer needs to have a certain thickness. Specifically, in some embodiments, the thickness of the metal-based doping layer is not less than 0.05mm (≧ 0.05 mm). The appropriate thickness of the metal doped layer helps to ensure the wear resistance of the material, and the long-term wear resistance required by folding and opening of 15-25 ten thousand times can be realized at the thickness.

In some embodiments, the metal-based doped layer has a thickness of 0.1 to 10mm, further 0.1 to 8mm, further 0.2 to 8mm, further 0.5 to 6 mm; typically, but not by way of limitation, the thickness of the metal-based doped layer may be, for example, 0.1mm, 0.2mm, 0.5mm, 0.8mm, 1mm, 2mm, 3mm, 4mm, 5mm, 6mm, 7mm, 8mm, 9mm, 10mm, and any value in the range of any two of these point values.

By controlling the thickness of the metal-based doped layer within a proper range, the wear-resisting property of the material is ensured, and the cost can be reduced. When the thickness of the metal-based doped layer is too small, the effects of enhancing wear resistance and self-lubrication cannot be achieved, and the required long-term wear resistance cannot be achieved; when the thickness of the metal-based doping layer is too large, the doping layer is too thick, the cost is high, and the performance is not obviously improved.

According to product requirements, the first steel material and the second steel material can be the same steel material or steel materials with different components. It should be noted that, in the embodiments of the present application, the specific number of layers of the composite material is also not limited, and the composite material may have a two-layer structure, or may have a three-layer or more-layer structure.

Specifically, in some embodiments, the first steel material and the second steel material are each independently carbon steel or alloy steel, i.e., the first steel material may be carbon steel or alloy steel, the second steel material may be carbon steel or alloy steel, and the specific compositional content of the first steel material and the second steel material may be the same or different.

Wherein the alloy steel comprises stainless steel. The stainless steel has the characteristics of good corrosion resistance, high hardness and the like. The specific type or grade of stainless steel has many forms.

Illustratively, the stainless steel may be 17-4 stainless steel, the 17-4 stainless steel is a MIM stainless steel grade, and the 0Cr17Ni4Cu4Nb is a martensitic precipitation hardening stainless steel, and the chemical composition in mass percent is as follows: c, carbon C: less than or equal to 0.07, manganese Mn: 1.00 or less, silicon Si: less than or equal to 1.00, chromium Cr: 15.5-17.5, nickel Ni: 3.0-5.0, phosphorus P: less than or equal to 0.04, sulfur S: less than or equal to 0.03, Cu: 3.0-5.0, niobium + tantalum Nb + Ta: 0.15-0.45 wt%, and the balance Fe.

Illustratively, the stainless steel can be 420 stainless steel, and the 420 stainless steel is a stainless steel grade, and the chemical compositions in percentage by mass are as follows: c, carbon C: 0.16 to 0.25, Mn: 1.00 or less, silicon Si: less than or equal to 1.00, chromium Cr: 12.0 to 14.0, Ni: less than or equal to 0.75, phosphorus P: less than or equal to 0.04, sulfur S: less than or equal to 0.03, and the balance of Fe.

Illustratively, the stainless steel can be 316 stainless steel, and the 316 stainless steel is a stainless steel grade, and the chemical components by mass percent are as follows: less than or equal to 0.08 percent of C, less than or equal to 1.00 percent of Si, less than or equal to 2.00 percent of Mn, less than or equal to 0.035 percent of P, less than or equal to 0.03 percent of S, 10.0 to 14.0 percent of Ni, 16.0 to 18.5 percent of Cr, 2.0 to 3.0 percent of Mo, and the balance of Fe.

It should be noted that the specific grade or type of stainless steel is not limited to the above listed grades, and other grades of stainless steel may be used to meet the performance requirements of the composite material.

In order to meet the process requirements of the preparation process or to achieve the required performance requirements, the grain sizes (particle sizes) of the first steel material and the second steel material also need to be within a suitable range. In some embodiments, the first steel material has an average particle size of not more than 30 μm (≦ 30 μm), may be 1 to 30 μm, may further be 2 to 15 μm, may further be 2 to 20 μm, may further be 10 to 20 μm, and the like.

And/or the average grain size of the second steel material is not more than 30 μm (less than or equal to 30 μm), can be 1-30 μm, further can be 2-15 μm, further can be 2-20 μm, further can be 10-20 μm, and the like. The specific value of the average grain size of the first steel material and the second steel material can be selected and set according to the actual process requirements, and is not limited too much.

[ method for producing composite Material ]

The molding process of the above composite material will be described in detail below.

In particular, in some embodiments, there is provided a method of making a composite material comprising the steps of:

forming a green body of a substrate layer, wherein the substrate layer is made of a first steel material; and forming a green body of the metal-based doping layer on the surface of the green body of the substrate layer, wherein the green body of the metal-based doping layer is laminated with the green body of the substrate layer, and the material of the metal-based doping layer comprises a second steel material and carbide.

And sintering and heat treating the green body of the base material layer and the green body of the metal-based doping layer which are arranged in a laminated manner to obtain the composite material.

The preparation method is simple to operate, easy to implement and easy to realize large-scale production. Meanwhile, the prepared composite material comprises the substrate layer and the metal-based doping layer which are sequentially stacked, and has the advantages as described in the composite material part.

In the embodiments of the present invention, the metal-based doping layer may be formed on one surface of the substrate layer, or the metal-based doping layers may be formed on both surfaces of the substrate layer. Preferably, a metal-based doping layer is formed on one surface of the substrate layer.

In some embodiments, the material of the metal-based doped layer includes a second steel material, a carbide, and a sulfide.

It should be understood that in the method for preparing the composite material, the specific structure and components of the composite material and the obtained beneficial effects can be referred to the previous description of the composite material, and are not repeated herein.

In some embodiments, the method of forming the substrate layer and the metal-based doping layer may be various, including but not limited to powder injection molding, pressure molding (e.g., powder press molding), curing molding, and the like.

The following explains key terms in the molding process of the composite material.

Powder Injection Molding (PIM) includes ceramic Powder Injection Molding (CIM) and Metal Powder Injection Molding (MIM). Specifically, powder injection molding: firstly, selecting ceramic powder or metal powder meeting CIM requirements and an adhesive, then mixing the powder and the adhesive into uniform feed by adopting a proper method at a certain temperature, granulating, then carrying out injection molding to obtain a molded blank, degreasing, sintering and compacting to obtain a final finished product.

Metal powder injection molding: is a molding method in which a plasticized mixture of metal powder and its binder is injected into a mold. The method comprises the steps of mixing the selected powder with a binder, granulating the mixture, and then performing injection molding on the mixture to obtain the required shape.

The press molding may include press molding and isostatic pressing. Wherein, compression molding (or dry compression molding): the powder with good fluidity and proper grain level is put into a mould and pressed into a green body with a certain shape by applying external force.

Isostatic pressing: the method of forming by utilizing incompressibility and uniform pressure transmission of a liquid medium is also called hydrostatic forming, and is divided into hot isostatic pressing and cold isostatic pressing.

Hot isostatic pressing is also known as high temperature isostatic pressing: the metal foil is used to replace the rubber film, and the gas is used to replace the liquid, so that the powder in the metal foil is uniformly pressed, the commonly used gas is inert gas such as helium, argon and the like, and the processed object is pressed to a high temperature of hundreds of ℃ to 2000 ℃ under the air pressure of 100-300MPa to be molded and sintered.

Feeding: the metal powder and the organic binder are mixed into uniform feed material by adopting a proper method under a certain temperature condition, and the organic binder can be gasified and disappear under the condition of high temperature in the subsequent sintering process.

It should be noted that the binder used in feeding is not limited in particular, and the binder may be any binder commonly used in the art, and may be selected and set by those skilled in the art according to actual situations, and will not be described in detail here.

In the molding method, the powder injection molding and the powder compression molding have the advantages of simple method, easy operation, high feasibility, good reliability, lower cost, high production efficiency and the like. Accordingly, the molding process of the composite material of the embodiments of the present invention is preferably a powder injection molding or pressure molding technique.

Fig. 10 is a schematic flow chart of powder injection molding to prepare the composite material, and as shown in fig. 10, the upper and lower layers (the substrate layer and the metal-based doping layer) can be formed by two-time injection molding by using the powder injection molding to prepare the layered composite material.

Specifically, in some embodiments, the composite material is prepared using powder injection molding, including the steps of:

(a) providing a first feed containing a first steel material, and performing primary powder injection molding by adopting the first feed to obtain a green body of the substrate layer;

(b) providing a second feed containing a second steel material and carbide, and performing secondary powder injection molding on the surface of the green body of the substrate layer by adopting the second feed to obtain a green body comprising the stacked substrate layer and a metal-based doped layer;

(c) and sintering and heat-treating the green body of the base material layer and the green body of the metal-based doping layer which are arranged in a laminated manner to obtain the composite material.

It should be noted that, in other embodiments, step (b) may also be: and providing a second feed containing a second steel material, carbide and sulfide, and performing secondary powder injection molding on the surface of the green body of the substrate layer by adopting the second feed to obtain a green body comprising the stacked substrate layers and the metal-based doping layer.

In some embodiments, the sintering temperature is 1100-; the sintering temperature mainly refers to a peak sintering temperature.

The heat preservation time is 2-3h, and further can be 2h, 2.5h or 3 h.

In some embodiments, the heat treatment comprises solution treatment and aging treatment, wherein the solution temperature of the solution treatment is 1000-1100 ℃, further 1020-1080 ℃, further 1030-1060 ℃, further 1035-1060 ℃; the time is 1-3h, further 1h, 2h or 3 h.

The aging temperature of the aging treatment is 400-500 ℃, further 420-480 ℃, further 440-470 ℃ and further 445-460 ℃; the time is 3-5h, and further may be 3h, 4h or 5 h.

According to the embodiment of the invention, the inventor conducts a great deal of thorough investigation and experimental verification on specific operation conditions of powder injection molding, sintering, heat treatment and the like, and finds that the quality and the performance of the formed laminated composite material are better, the production efficiency is higher, the energy consumption is lower, the finally obtained composite material can meet the required long-term wear resistance, and the product performance and the user experience are good.

Fig. 11 is a schematic flow chart of powder press molding for preparing the composite material, and as shown in fig. 11, the upper layer and the lower layer (the substrate layer and the metal-based doped layer) can be pressed and molded in a powder spreading manner by using the powder press molding for preparing the layered composite material.

Specifically, in other embodiments, the composite material is prepared by powder compaction, comprising the steps of:

(a) providing first steel material powder, and performing first powder pressing forming by using the first steel material powder to obtain a green body of the substrate layer;

(b) providing mixed powder containing a second steel material and carbide, and performing secondary powder pressing forming on the surface of the green body of the substrate layer by adopting the mixed powder to obtain a green body comprising the stacked substrate layer and a green body comprising the metal-based doping layer;

(c) and sintering and heat-treating the green body of the base material layer and the green body of the metal-based doping layer which are arranged in a laminated manner to obtain the composite material.

It should be noted that, in other embodiments, step (b) may also be: and providing mixed powder containing a second steel material, carbide and sulfide, and performing secondary powder pressing forming on the surface of the green body of the substrate layer by adopting the mixed powder to obtain a green body comprising the stacked substrate layer and the metal-based doped layer.

In some embodiments, the sintering temperature is 1100-; the sintering temperature mainly refers to a peak sintering temperature.

The heat preservation time is 2-3h, and further can be 2h, 2.5h or 3 h.

In some embodiments, the heat treatment comprises solution treatment and aging treatment, wherein the solution temperature of the solution treatment is 1000-1100 ℃, further 1020-1080 ℃, further 1030-1060 ℃, further 1035-1060 ℃; the time is 1-3h, further 1h, 2h or 3 h.

The aging temperature of the aging treatment is 400-500 ℃, further 420-480 ℃, further 440-470 ℃ and further 445-460 ℃; the time is 3-5h, and further may be 3h, 4h or 5 h.

In some embodiments, the heat treatment is followed by a hot isostatic pressing treatment.

According to the embodiment of the invention, the inventor carries out a great deal of thorough investigation and experimental verification on specific operation conditions of powder press forming, sintering, heat treatment and the like, and finds that the quality and the performance of the formed laminated composite material are better, the production efficiency is higher, the energy consumption is lower, the finally obtained composite material can meet the required long-term wear resistance, and the product performance and the user experience are good.

In summary, the composite material, the preparation method thereof, the rotating mechanism and the electronic device provided by the embodiment of the invention adopt a mode of preparing the layered composite material to prepare the metal-based doped layer containing materials such as carbide and the like, rather than adopting a mode of high-temperature carburization; this has no effect on the hardness and strength of the substrate. The surface coating is replaced by a high-hardness self-lubricating material layer (namely a metal-based doping layer) with the thickness of more than or equal to 0.05mm (or 0.1mm), so that the coating has better wear resistance and self-lubricating property. The addition of the ceramic phase of the metal-based doped layer on the surface layer is beneficial to improving the surface hardness, and the wear resistance is better.

The effects of the present invention will be described below with reference to specific examples, but the scope of the present invention is not limited by the following examples. In the examples of the present invention, various raw materials can be obtained in a commercially available manner. The first embodiment, the third embodiment, the fifth embodiment and the seventh embodiment adopt the powder injection molding mode for preparation, and the second embodiment, the fourth embodiment and the sixth embodiment adopt the powder compression molding mode. The volume percentages of the second steel material, carbide, and sulfide in the metal-based doped layers of examples one, two, and three are different; the specific type of carbide in the metal-based doped layers of examples one, four and five is different; the metal-based doped layers of examples six and seven included only the second steel material and carbide.

Example one

Preparation of raw materials

1. Substrate layer: 17-4 stainless steel feed material mainly composed of stainless steel powder, wherein the average grain size of the stainless steel powder is about 2-15 μm;

2. metal-based doping layer (surface layer): 17-4 of stainless steel powder, silicon carbide powder and molybdenum sulfide powder, which are mixed according to the volume percentage of 40%, 30% and 30% to form mixed particle powder; wherein the average particle size of the stainless steel powder is about 2-15 μm, the silicon carbide powder particles are all below 10 μm, and the molybdenum sulfide powder particles are also below 10 μm. The mixed powder and the high polymer material adhesive are uniformly mixed to form mixed powder feed.

Process for preparing component

1. Firstly injecting 17-4 stainless steel feed by MIM powder;

2. injecting mixed powder for feeding;

thereby forming two feeding structures which are arranged in a layer shape.

3. Sintering the double-layer feeding structure material, wherein the peak value sintering temperature is 1150 ℃, and the heat preservation time is 2 hours;

4. and (3) carrying out heat treatment on the sintered piece, wherein the solid solution temperature is 1040 ℃, the time is 2 hours, the aging temperature is 460 ℃, and the time is 4 hours.

Thirdly, the formed material structure

The material of the surface layer is 17-4 stainless steel doped with silicon carbide and molybdenum sulfide particles, and the material of the base material layer (bottom layer) is 17-4 stainless steel; the comprehensive hardness is above 1400HV, the distribution of molybdenum sulfide on the surface layer plays a certain role of lubrication, and the friction coefficient of the material is below 0.1.

Wherein the average thickness of the metal-based doped layer after sintering is 0.15 mm.

In the embodiment, the hardness of the silicon carbide is about 2100HV, the hardness of the stainless steel base material is more than 350HV, the silicon carbide is still used for the comprehensive hardness to play a role of wear resistance, and meanwhile, due to the distribution of the molybdenum sulfide metal base doped layer, the molybdenum sulfide metal base doped layer plays a role of lubricating parts made of the material, has great benefits on wear resistance, and can play a role of replacing lubricating oil to a certain extent.

Therefore, compared with the original stainless steel and the existing stainless steel silicon carbide-doped particles, the wear resistance of the stainless steel is greatly improved.

Example two

Preparation of raw materials

1. Substrate layer: 420 stainless steel powder is used as the stainless steel feed material which is mainly composed of the stainless steel powder, and the average grain size of the stainless steel powder is about 2-15 mu m;

2. metal-based doping layer (surface layer): 420 percent of stainless steel powder, 40 percent of silicon carbide powder and 30 percent of molybdenum sulfide powder are mixed by volume percentage to form mixed particle powder, wherein the average particle size of the stainless steel powder is about 2-15 mu m, the particle size of the silicon carbide powder is below 10 mu m, and the particle size of the molybdenum sulfide powder is below 10 mu m.

Process for preparing component

1. Firstly, powder pressing 420 stainless steel powder;

2. pressing mixed powder required by the surface layer on the 420 stainless steel powder;

thus forming two powder structures which are arranged in a layer.

3. Sintering the double-layer powder structure material, wherein the peak value sintering temperature is 1130 ℃, and the heat preservation time is 2 hours;

4. and (3) carrying out heat treatment on the sintered piece, wherein the solid solution temperature is 1035 ℃ and the time is 2 hours, the aging temperature is 445 ℃ and the time is 3.5 hours.

Thirdly, the formed material structure

The material of the surface layer is 420 stainless steel doped with silicon carbide and molybdenum sulfide particles, and the material of the bottom layer is 420 stainless steel; the comprehensive hardness is above 1450HV, the distribution of molybdenum sulfide on the surface layer plays a certain role of lubrication, and the friction coefficient of the material is below 0.1.

Wherein the average thickness of the sintered surface layer is 0.12 mm.

In the embodiment, the hardness of the silicon carbide is about 2100HV, the hardness of the stainless steel base material is more than 350HV, the silicon carbide is still used for the comprehensive hardness to play a role of wear resistance, and meanwhile, due to the distribution of molybdenum sulfide on the surface layer, the silicon carbide lubricating material plays a role of lubricating parts made of the silicon carbide lubricating material, has great benefits on wear resistance, and can replace lubricating oil to a certain extent.

Therefore, compared with the original stainless steel and the possible existing stainless steel silicon carbide-doped particles, the wear resistance of the stainless steel is greatly improved; particularly, the proportion of the silicon carbide is increased, so that the hardness and the wear resistance are improved.

EXAMPLE III

Preparation of raw materials

1. Substrate layer: 316 stainless steel powder is used as the stainless steel feed material which is mainly composed of stainless steel powder, and the average grain diameter of the stainless steel powder is below 30 mu m;

2. metal-based doping layer (surface layer): 17-4 stainless steel powder, silicon carbide powder and molybdenum sulfide powder, wherein the stainless steel powder has an average particle size of below 30 μm, the silicon carbide powder particles are below 10 μm and the molybdenum sulfide powder particles are below 10 μm, which are mixed in the volume percentages of 20%, 70% and 10% to form mixed particle powder. The mixed powder and the high polymer material adhesive are uniformly mixed to form mixed powder feed.

Process for preparing component

1. MIM powder injection 316 stainless steel feed;

2. injecting 17-4 stainless steel base mixed powder feed;

thereby forming two feeding structures which are arranged in a layered manner;

3. sintering the double-layer feeding structure material, wherein the peak value sintering temperature is 1140 ℃, and the heat preservation time is 2 hours;

4. and (3) carrying out heat treatment on the sintered piece, wherein the solid solution temperature is 1030 ℃ and the time is 2 hours, the aging temperature is 450 ℃ and the time is 4 hours.

Thirdly, the formed material structure

The surface layer is 17-4 stainless steel doped with silicon carbide and molybdenum sulfide particles, and the bottom layer is 316 stainless steel; the comprehensive hardness is above 1400HV, the distribution of molybdenum sulfide on the surface layer plays a certain role of lubrication, and the friction coefficient of the material is below 0.1.

Wherein the average thickness of the sintered surface layer is 1.2 mm.

In the embodiment, a ceramic-like layer is formed on the surface layer, the volume percentage content of silicon carbide reaches 70%, the metal only plays a role of bonding ceramics and connecting with the bottom layer metal, the surface of the metal ceramic mainly comprises ceramic phases, and the hardness of the surface layer can reach more than 1800HV, so that the metal ceramic is extremely good for wear resistance.

The embodiment is different from other embodiments in that the ceramic phase is lifted, so that extremely wear-resistant metal ceramic is formed on the surface, the hardness of the surface layer is greatly improved, and the wear resistance is facilitated. The stainless steel materials of the upper layer and the lower layer are different, but the stainless steel materials contain the same first main element Fe and second main element Cr.

Example four

Preparation of raw materials

1. Substrate layer: 17-4 stainless steel feed material mainly composed of stainless steel powder, wherein the average grain size of the stainless steel powder is 10-20 μm;

2. metal-based doping layer (surface layer): 17-4 stainless steel powder, tungsten carbide powder and molybdenum sulfide powder, wherein the stainless steel powder, the tungsten carbide powder and the molybdenum sulfide powder are mixed according to the volume percentages of 30%, 50% and 20% to form mixed particle powder, the average particle size of the stainless steel powder is 10-20 mu m, the average particle size of the tungsten carbide powder is below 10 mu m, and the average particle size of the molybdenum sulfide powder is below 10 mu m.

Process for preparing component

1. Firstly, powder pressing 17-4 stainless steel powder in a mould;

2. pressing the mixed powder required by the surface layer on 17-4 stainless steel powder in the same die;

thus forming two powder structures which are arranged in a layer.

3. Sintering the double-layer powder structure material. Wherein the peak value sintering temperature is 1300 ℃, and the heat preservation time is 3 hours;

4. the sintered piece is subjected to heat treatment, the solid solution temperature is 1060 ℃, the time is 2 hours, the aging temperature is 450 ℃, and the time is 4.5 hours.

5. And (4) carrying out isostatic pressing treatment on the prepared parts.

Thirdly, the formed material structure

The surface layer is 17-4 stainless steel doped with tungsten carbide and molybdenum sulfide particles, and the bottom layer is 17-4 stainless steel; the comprehensive hardness is more than 1500HV, the distribution of molybdenum sulfide on the surface layer plays a certain role of lubrication, and the friction coefficient of the material is less than 0.1.

Wherein the average thickness of the sintered surface layer is 2 mm.

In the embodiment, the hardness of the tungsten carbide is about 2100HV, the hardness of the stainless steel base material is more than 350HV, the tungsten carbide is still used for the comprehensive hardness, and meanwhile, due to the distribution of molybdenum sulfide on the surface layer, the tungsten carbide lubricating material has a lubricating effect on parts made of the tungsten carbide lubricating material, has a great benefit on wear resistance, and replaces lubricating oil to a certain extent.

The main difference between this embodiment and the other embodiments is that this embodiment uses tungsten carbide powder, which also has high hardness and can maintain a certain toughness of the surface layer.

EXAMPLE five

Preparation of raw materials

1. Substrate layer: 316 stainless steel powder is used as the stainless steel feed material which is mainly composed of stainless steel powder, and the average grain diameter of the stainless steel powder is below 30 mu m;

2. metal-based doping layer (surface layer): 316 stainless steel powder, titanium carbide powder and molybdenum sulfide powder, wherein the average grain size of the stainless steel powder is below 30 μm, the average grain size of the titanium carbide powder is below 10 μm, and the average grain size of the molybdenum sulfide powder is below 10 μm, are mixed in volume percentages of 10%, 80% and 10% to form granular powder. The mixed powder and the high polymer material adhesive are uniformly mixed to form mixed powder feed.

Process for preparing component

1. MIM powder injection 316 stainless steel feed;

2. injecting mixed powder for feeding;

thereby forming two feeding structures which are arranged in a layer shape.

3. Sintering the double-layer feeding structure material, wherein the peak value sintering temperature is 1350 ℃, and the heat preservation time is 2 hours;

4. and (3) carrying out heat treatment on the sintered piece, wherein the solid solution temperature is 1030 ℃ and the time is 2 hours, the aging temperature is 450 ℃ and the time is 4 hours.

Thirdly, the formed material structure

The surface layer is 316 stainless steel doped with titanium carbide and molybdenum sulfide particles, and the bottom layer is 316 stainless steel; the comprehensive hardness is above 1400HV, the distribution of molybdenum sulfide on the surface layer plays a certain role of lubrication, and the friction coefficient of the material is below 0.1.

Wherein the average thickness of the sintered surface layer is 2 mm.

In this embodiment, a ceramic-like layer is formed on the surface layer, the volume percentage content of titanium carbide (with the hardness of 3000HV or more) reaches 80%, the metal only plays a role of bonding ceramic and connecting with the metal at the bottom layer, the surface forms cermet mainly containing ceramic phase, and the hardness of the surface layer can reach 2500HV or more. This has a great advantage in terms of wear resistance.

The embodiment is different from other embodiments in that the ceramic phase is lifted, so that extremely wear-resistant metal ceramic is formed on the surface, the hardness of the surface layer is greatly improved, and the wear resistance is facilitated.

EXAMPLE six

Preparation of raw materials

1. Substrate layer: 17-4 stainless steel feed material mainly composed of stainless steel powder, wherein the average grain size of the stainless steel powder is 10-20 μm;

2. metal-based doping layer (surface layer): 17-4 stainless steel powder and silicon carbide powder, wherein the stainless steel powder and the silicon carbide powder are mixed according to the volume percentage of 50% and 50% to form particle powder, the average particle size of the stainless steel powder is 10-20 mu m, and the particle size of the silicon carbide powder is below 10 mu m.

Process for preparing component

1. Firstly, powder pressing 17-4 stainless steel powder in a mould;

2. pressing the mixed powder required by the surface layer on 17-4 stainless steel powder in the same die;

thus forming two powder structures which are arranged in a layer.

3. Sintering the double-layer powder structure material, wherein the peak value sintering temperature is 1300 ℃, and the heat preservation time is 3 hours;

4. the sintered piece is subjected to heat treatment, the solid solution temperature is 1060 ℃, the time is 2 hours, the aging temperature is 450 ℃, and the time is 4.5 hours.

5. And carrying out hot isostatic pressing on the manufactured parts.

Thirdly, the formed material structure

The surface layer is 17-4 stainless steel doped with silicon carbide particles, and the bottom layer is 17-4 stainless steel; the comprehensive hardness is more than 1500 HV.

Wherein the average thickness of the sintered surface layer is 2 mm.

In this embodiment, a ceramic-like layer is formed on the surface layer, the volume percentage content of silicon carbide (with the hardness of 2100HV or more) reaches 50%, the metal only plays a role of bonding ceramics and connecting with the metal at the bottom layer, the surface forms cermet mainly containing ceramic phase, and the hardness of the surface layer can reach 1600HV or more. This has a great advantage in terms of wear resistance.

In this example, only silicon carbide was doped, molybdenum sulfide was not added, and a layered composite material was also formed.

EXAMPLE seven

Preparation of raw materials

1. Substrate layer: 316 stainless steel powder is used as the stainless steel feed material which is mainly composed of stainless steel powder, and the average grain diameter of the stainless steel powder is below 30 mu m;

2. metal-based doping layer (surface layer): 17-4 stainless steel powder and tungsten carbide powder, wherein the stainless steel powder and the tungsten carbide powder are mixed according to the volume percentage of 20% and 70% to form particle powder, the average particle size of the stainless steel powder is below 30 mu m, and the particle size of the tungsten carbide powder is below 10 mu m. The mixed powder and the high polymer material adhesive are uniformly mixed to form mixed powder feed.

Process for preparing component

1. MIM powder injection 316 stainless steel feed;

2. injecting 17-4 stainless steel base mixed powder feed;

thereby forming two feeding structures which are arranged in a layered manner;

3. sintering the double-layer feeding structure material, wherein the peak value sintering temperature is 1400 ℃, and the heat preservation time is 2 hours;

4. and (3) carrying out heat treatment on the sintered piece, wherein the solid solution temperature is 1030 ℃ and the time is 2 hours, the aging temperature is 450 ℃ and the time is 4 hours.

Thirdly, the formed material structure

The surface layer is 17-4 stainless steel doped with tungsten carbide particles, and the bottom layer is 316 stainless steel; the comprehensive hardness is above 2000 HV.

Wherein the average thickness of the sintered surface layer is 1.2 mm.

In the embodiment, the surface layer forms a ceramic-like layer, the volume percentage content of the tungsten carbide reaches 70%, the metal only plays a role of bonding the ceramic and a role of connecting the bottom layer metal, and the surface forms the cermet mainly comprising the ceramic phase, so that the wear resistance is greatly improved.

The embodiment mainly uses ceramic-phase tungsten carbide without molybdenum sulfide, is favorable for reducing cost and realizing wear resistance, and can be applied to different application scenes.

It should be noted that the term "and/or"/"used herein is only one kind of association relationship describing associated objects, and means that there may be three relationships, for example, a and/or B, and may mean: a exists alone, A and B exist simultaneously, and B exists alone. As used in the examples of this application and the appended claims, the singular forms "a", "an", and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise.

The use of "first," "second," and similar terms in the present application do not denote any order, quantity, or importance, but rather the terms are used to distinguish one element from another. The terms "connected" or "coupled" and the like are not restricted to physical or mechanical connections, but may include electrical connections, whether direct or indirect.

In the description of the present application, it is to be understood that the terms "upper", "lower", and the like indicate orientations or positional relationships and are used only for indicating relative positional relationships, and when the absolute position of a described object is changed, the relative positional relationships may be changed accordingly. It will also be understood that when an element such as a layer or substrate is referred to as being "on" or "under" another element, it can be directly on or under the other element or indirectly on or under the other element via intervening elements.

It is noted that a portion of this patent application contains material which is subject to copyright protection. The copyright owner reserves the copyright rights whatsoever, except for making copies of the patent files or recorded patent document contents of the patent office.