阅读说明：本技术 一种用于高盐环境的内啮合齿轮及其制备方法 (Internal gear for high-salt environment and preparation method thereof ) 是由 周超 王守仁 王高琦 孙秀怀 张建鹏 李重阳 刘文龙 薛成龙 李金坤 于 2021-07-13 设计创作，主要内容包括：本发明涉及一种用于高盐环境的内啮合齿轮及其制备方法,其包括芯材、覆设在芯材表面的内、中、外涂层。芯材采用40Cr材料制作。按照重量百分比计：内涂层含有39.5％至40.5％的Ni60和59.5％至60.5％的WC。中间涂层含有70.5％至72.5％的Ni60、26.5％至27.5％的WC和1％至2％的CeO-(2)。外涂层含有87.5％至89.5％的Ni60、9.5％至10.5％的Mo和1％至2％的CeO-(2)。本发明针对温度高、盐浓度大运行环境下,内啮合齿轮耐磨性能差、使用寿命短的问题,通过在齿轮的轮齿表面增材获得含有不同梯度涂层的齿轮结构,使齿轮具有不同的梯度性能,实现提高齿轮的耐磨耐腐蚀性能的目的,提高了齿轮的使用寿命,保证了齿轮泵安全、高效的运行。(The invention relates to an inner meshing gear used in high salt environment and a preparation method thereof. The core material is made of 40Cr material. According to the weight percentage: the inner coating contains 39.5% to 40.5% Ni60 and 59.5% to 60.5% WC. The intermediate coating contains 70.5 to 72.5% of Ni60, 26.5 to 27.5% of WC and 1 to 2% of CeO 2 . The outer coating contains 87.5-89.5% of Ni60, 9.5-10.5% of Mo and 1-2% of CeO 2 . Aiming at the problems of poor wear resistance and short service life of an internal gear under the operating environment with high temperature and high salt concentration, the invention obtains different ladders by adding materials on the surface of the gear teeth of the gearThe gear structure of degree coating makes the gear have different gradient performance, realizes improving the wear-resisting corrosion resisting property's of gear purpose, has improved the life of gear, has guaranteed safe, the efficient operation of gear pump.)

1. A ring gear for high salt environment, includes core material, its characterized in that: the coating also comprises an inner coating, a middle coating and an outer coating which are sequentially coated on the surface of the core material; the core material is made of 40Cr material;

the components and the proportion of each coating are set as follows according to the weight percentage;

the inner coating contains 39.5% to 40.5% Ni60 and 59.5% to 60.5% WC;

the intermediate coating contains 70.5 to 72.5% of Ni60, 26.5 to 27.5% of WC and 1 to 2% of CeO₂；

The outer coating contains 87.5-89.5% of Ni60, 9.5-10.5% of Mo and 1-2% of CeO₂。

2. A ring gear for use in high salt environments as claimed in claim 1, wherein: the layer thickness of the inner coating is between 40mm and 60 mm.

3. A ring gear for use in high salt environments as claimed in claim 1, wherein: the thickness of the intermediate coating is between 20mm and 40 mm.

4. A ring gear for use in high salt environments as claimed in claim 1, wherein: the thickness of the outer coating is between 10mm and 30 mm.

5. A method for preparing a ring gear used in a high salt environment is characterized in that: the core material of the gear is made of 40Cr material, an inner coating, a middle coating and an outer coating are sequentially arranged on the surface of the core material from inside to outside, and the coating comprises the following components in percentage by weight:

mixing Ni60 powder and WC powder to prepare the composite powder of the inner coating, wherein the weight proportion of the Ni60 powder is 39.5-40.5%, and the weight proportion of the WC powder is 59.5-60.5%;

using Ni60 powder, WC powder and CeO₂Powder is mixed to prepare the composite powder of the intermediate coating, wherein the weight ratio of Ni60 powder is 70.5 to 72.5 percent, the weight ratio of WC powder is 26.5 to 27.5 percent, and the CeO₂The weight ratio of the powder is 1 to 2 percent;

using Ni60 powder, Mo powder and CeO₂Mixing the powders to obtain composite powder for preparing the outer coating, wherein the weight ratio of Ni60 powder is 87.5-89.5%, the weight ratio of Mo powder is 9.5-10.5%, and the CeO₂The weight ratio of the powder is 1 to 2 percent;

the preparation method comprises the following steps:

(1) pretreating the surface of the core material to remove oil stains, oxide layers and impurities on the surface;

(2) an inner coating is added and coated on the surface of the core material by adopting a 3D printing means, and the surface of the core material is polished to be flat after the inner coating is shaped;

(3) the surface of the inner coating is additively coated with an intermediate coating by adopting a 3D printing means, and the surface of the intermediate coating is polished to be flat after the intermediate coating is shaped;

(4) and (3) performing additive coating on the surface of the intermediate coating by adopting a 3D printing means, and polishing the surface of the intermediate coating to be flat after the outer coating is shaped.

6. A method of making a ring gear for use in high salt environments as set forth in claim 5, wherein: the composite powder with the inner coating prepared according to the proportion is sequentially subjected to ball milling treatment, absolute ethyl alcohol cleaning treatment and drying treatment.

7. A method of making a ring gear for use in high salt environments as claimed in claim 5 or 6, wherein: the composite powder prepared into the intermediate coating in proportion is sequentially subjected to ball milling treatment, absolute ethyl alcohol cleaning treatment and drying treatment.

8. A method of making a ring gear for use in high salt environments as set forth in claim 7, wherein: the composite powder prepared into the outer coating in proportion is sequentially subjected to ball milling treatment, absolute ethyl alcohol cleaning treatment and drying treatment.

9. A method of making a ring gear for use in high salt environments as set forth in claim 5, wherein: the composite powder prepared into the outer coating in proportion is sequentially subjected to ball milling treatment, absolute ethyl alcohol cleaning treatment and drying treatment.

10. A method of making a ring gear for use in high salt environments as set forth in claim 9, wherein: the composite powder with the inner coating prepared according to the proportion is sequentially subjected to ball milling treatment, absolute ethyl alcohol cleaning treatment and drying treatment.

Technical Field

The invention relates to the technical field of 3D printing additive manufacturing, in particular to an inner meshing gear which is manufactured by using a 3D printing additive technology and can be used in a high-salt environment and a preparation method thereof.

Background

The development and utilization of marine resources are concerned, and the key friction pair in marine engineering equipment bears not only the abrasion caused by mutual contact between the friction pair, but also the corrosion of seawater, and the interaction between the corrosion of seawater and the abrasion between the friction pair, which accelerates the damage of the key friction pair, and finally leads to the failure of the key friction pair.

The seawater after desalination has high temperature and high salt concentration, and when the seawater is transported by adopting the internal gear pump, the gear pair which is meshed with each other can bear abrasion caused by friction, and the interaction between the abrasion and the corrosion can greatly accelerate the abrasion failure speed of the gear due to the serious corrosion caused by the seawater with high salt concentration.

Aiming at the problems under the working condition of seawater, most of the previous solutions adopt different technologies to prepare wear-resistant and corrosion-resistant coatings on the surfaces of friction pairs. However, although the problem can be improved by only preparing a wear-resistant and corrosion-resistant coating on the surface of the friction pair, the single-layer coating has short service life, and defects, such as cracks, air holes and the like, can also exist in the process of preparing the single-layer coating, and the defects can easily cause seawater to permeate through the coating, so that the failure of the coating is accelerated, and even the coating is peeled off.

Disclosure of Invention

Aiming at the problems of poor wear resistance and short service life of an internal gear under the operating environment with high temperature and high salt concentration, the invention provides the internal gear used in the high-salt environment and the preparation method thereof. The gear structure containing different gradient coatings is obtained by adding materials on the surface of the gear teeth of the gear, so that the gear has different gradient properties, the purpose of improving the wear resistance and corrosion resistance of the gear is realized, the service life of the gear is prolonged, and the safe and efficient operation of the gear pump is ensured. Utilize 3D printing technique directly to print out the gear, still have low in manufacturing cost, advantage that the manufacturing process is nimble.

The technical scheme adopted by the invention for solving the technical problems is as follows: an inner ring gear used in high salt environment comprises a core material, an inner coating coated on the surface of the core material, an intermediate coating and an outer coating. In a specific embodiment, the core material is made into a cylindrical shape by a bar stock, an inner coating on the surface of the core material is additionally arranged to form a gear-shaped appearance, and then a middle coating and an inner coating are sequentially additionally arranged on the surface of the contour of the gear-shaped appearance.

The core material is made of 40Cr material. The weight percentages are set as follows.

The inner coating contains 39.5% to 40.5% Ni60 and 59.5% to 60.5% WC.

The intermediate coating contains 70.5 to 72.5% of Ni60, 26.5 to 27.5% of WC and 1 to 2% of CeO₂。

The outer coating contains 87.5-89.5% of Ni60, 9.5-10.5% of Mo and 1-2% of CeO₂。

Further, the layer thickness of the inner coating is between 40mm and 60mm, preferably in the interval of 45mm to 55 mm.

Further, the thickness of the intermediate coating is between 20mm and 40mm, preferably in the interval of 25mm to 35 mm.

Further, the thickness of the outer coating is between 10mm and 30mm, preferably in the interval 15mm to 25 mm.

In general, the actual thickness of the inner coating layer is set to be greater than the thickness of the intermediate coating layer, which is greater than the thickness of the outer coating layer. For example, the thickness of the inner coating layer is set to about 50mm, the thickness of the intermediate coating layer is set to about 30mm, and the thickness of the inner coating layer is set to about 20 mm.

A core material of the gear is made of 40Cr material, and an inner coating, a middle coating and an outer coating are sequentially arranged on the surface of the core material from inside to outside.

The coating layers are prepared from Ni60 powder, WC powder and CeO in a weight ratio₂Two or three of the powder and the Mo powder are compounded. Considering that in the manufacturing process, a few parts of particles are agglomerated due to electronegativity, the powder flow is influenced, and a certain loss is caused, the specific proportion of each powder component in percentage by weight is determined as follows.

The composite powder of the inner coating is prepared by mixing Ni60 powder and WC powder, wherein the weight ratio of the Ni60 powder is 39.5-40.5%, and the weight ratio of the WC powder is 59.5-60.5%.

Using Ni60 powder, WC powder and CeO₂Powder is mixed to prepare the composite powder of the intermediate coating, wherein the weight ratio of Ni60 powder is 70.5 to 72.5 percent, the weight ratio of WC powder is 26.5 to 27.5 percent, and the CeO₂The weight ratio of the powder is 1 to 2 percent.

Using Ni60 powder, Mo powder and CeO₂Mixing the powders to obtain composite powder for preparing the outer coating, wherein the weight ratio of Ni60 powder is 87.5-89.5%, the weight ratio of Mo powder is 9.5-10.5%, and the CeO₂The weight ratio of the powder is 1 to 2 percent.

The surface of the core material is pretreated to remove oil stains, oxide layers and impurities on the surface.

And (3) coating an inner coating on the surface of the core material in an additive manner by adopting a 3D printing means, and polishing the surface of the core material to be smooth after the inner coating is shaped.

And (3) the surface of the inner coating is subjected to material increase coating by adopting a 3D printing means, and the surface of the middle coating is polished to be smooth after the middle coating is shaped.

And (3) performing additive coating on the surface of the intermediate coating by adopting a 3D printing means, and polishing the surface of the intermediate coating to be flat after the outer coating is shaped.

Further, the composite powder with the inner coating prepared according to the proportion is subjected to ball milling treatment, so that the composite powder is uniformly mixed, and the particles are further refined. Then pouring the composite powder into absolute ethyl alcohol for cleaning. And finally, placing the composite powder into a drying oven for drying treatment, and using the composite powder after the drying treatment is finished and waiting for material increase.

Further, the composite powder of the intermediate coating prepared by the proportion is subjected to ball milling treatment, so that the composite powder is uniformly mixed, and the particles are further refined. Then pouring the composite powder into absolute ethyl alcohol for cleaning. And finally, placing the composite powder into a drying oven for drying treatment, and using the composite powder after the drying treatment is finished and waiting for material increase.

Further, the composite powder of which the outer coating is prepared according to the proportion is subjected to ball milling treatment, so that the composite powder is uniformly mixed, and the particles are further refined. Then pouring the composite powder into absolute ethyl alcohol for cleaning. And finally, placing the composite powder into a drying oven for drying treatment, and using the composite powder after the drying treatment is finished and waiting for material increase.

The invention has the beneficial effects that: the gear that this patent relates, it is to under the big operational environment of temperature height, salt concentration, problem that inside engagement gear wear resistance is poor, life is short, obtains the gear structure who contains different gradient coatings through the teeth of a cogwheel surface vibration material disk at the gear, makes the gear have different gradient performance, realizes improving the wear-resisting corrosion resisting property's of gear purpose, has improved the life of gear, has guaranteed gear pump safety, efficient operation. Utilize 3D printing technique directly to print out the gear, still have low in manufacturing cost, advantage that the manufacturing process is nimble.

Drawings

Fig. 1 is a schematic structural view (cross-section) of a ring gear according to the present invention.

In the figure: 1 core material, 2 inner coating layers, 3 middle coating layers and 4 outer coating layers.

Detailed Description

The structures, proportions, and dimensions shown in the drawings and described in the specification are for understanding and reading the present disclosure, and are not intended to limit the scope of the present disclosure, which is defined in the claims, and are not essential to the skilled in the art. In addition, the terms "upper", "lower", "front", "rear" and "middle" used in the present specification are for clarity of description, and are not intended to limit the scope of the present invention, and the relative relationship between the terms and the relative positions may be changed or adjusted without substantial technical changes.

A ring gear for use in a high salt environment as shown in fig. 1 includes a core material 1, an undercoat layer 2 coated on the surface of the core material 1, an intermediate coat layer 3, and an overcoat layer 4. In the embodiment shown in the figure, the core material 1 is made into a cylindrical shape by a bar material, the inner coating 2 arranged on the surface of the core material 1 is additionally arranged to form a gear-shaped appearance, and then the surface of the contour of the gear-shaped appearance is additionally provided with the middle coating 3 and the inner coating 4 in sequence.

The core material is made of 40Cr material, and a hole and a key groove are formed in the center of the disk surface.

The coating layers are prepared from Ni60 powder, WC powder and CeO in a weight ratio₂Two or three of the powder and the Mo powder are compounded. Considering that a very small part of particles are agglomerated due to electronegativity during the manufacturing process, the powder flow is affected, and certain loss is caused, the composition and the ratio of each coating layer are determined as follows.

The inner coating contains 39.5% to 40.5% Ni60 and 59.5% to 60.5% WC.

The intermediate coating contains 70.5 to 72.5% of Ni60, 26.5 to 27.5% of WC and 1 to 2% of CeO₂。

The outer coating contains 87.5 to 89.5% of Ni60, 9.5 to 10.5% of Mo and 1 to 2% of CeO₂。

In conventional designs, the layer thickness of the inner coating is between 40mm and 60mm, preferably in the interval from 45mm to 55 mm. The thickness of the intermediate coating is between 20mm and 40mm, preferably in the interval 25mm to 35 mm. The thickness of the outer coating is between 10mm and 30mm, preferably in the interval 15mm to 25 mm.

It is required that the thickness of the actually provided inner coating layer is larger than that of the intermediate coating layer, which is larger than that of the outer coating layer. For example, the thickness of the inner coating layer is set to about 50mm, the thickness of the intermediate coating layer is set to about 30mm, and the thickness of the inner coating layer is set to about 20 mm.

The method for manufacturing the above-mentioned gear is as follows:

1. and (3) processing the composite powder which is proportioned to form each coating.

After Ni60 powder and WC powder are mixed according to a proportion to prepare composite powder of an inner coating, the composite powder is firstly subjected to ball milling treatment, so that the composite powder is uniformly mixed, and particles are further refined. Then pouring the composite powder into absolute ethyl alcohol for cleaning. And finally, placing the composite powder into a drying box for drying treatment, and after the drying treatment is finished, waiting for an additive inner coating to be used, wherein the inner coating is additionally arranged on the surface of the core material, and the outline of the inner coating is formed into a gear-shaped outline.

Using Ni60 powder, WC powder and CeO₂After the powder is mixed according to the proportion to prepare the composite powder of the intermediate coating, firstly, the composite powder is subjected to ball milling treatment, so that the composite powder is uniformly mixed, and the particles are further refined. Then pouring the composite powder into absolute ethyl alcohol for cleaning. And finally, placing the composite powder into a drying oven for drying treatment, and using the composite powder after the drying treatment is finished and waiting for adding an intermediate coating.

Using Ni60 powder, Mo powder and CeO₂After the powder is mixed according to the proportion to prepare the composite powder of the outer coating, the composite powder is firstly subjected to ball milling treatment, so that the composite powder is uniformly mixed, and the particles are further refined. Then pouring the composite powder into absolute ethyl alcohol for cleaning. Finally, the composite powder is put into a drying oven for drying treatment, and the like after the drying treatment is finishedWhen the outer coating is added, the paint is used.

2. And (5) processing.

(1) And (4) pretreating the surface of the core material to remove oil stains, oxide layers and impurities on the surface.

(2) And (3) performing additive coating on the surface of the core material by using a 3D printing means, wherein the shape of the inner coating is additionally provided with a gear shape. And after the internal coating is shaped, the surface of the internal coating is polished to be smooth, so that the requirement of additionally arranging the intermediate coating is met.

(3) And (3) performing additive coating on the surface of the inner coating by using a 3D printing means, attaching the intermediate coating to the surface of the inner coating in the shape of the gear, and polishing the surface of the intermediate coating to be flat after the intermediate coating is shaped so as to meet the requirement of adding the outer coating.

(4) And (3) performing additive coating on the surface of the intermediate coating by using a 3D printing means, attaching the intermediate coating to the surface of the intermediate coating in the shape of the gear, and polishing the surface of the outer coating to be flat after the outer coating is shaped so as to meet the surface quality requirement of the internal gear.

In this patent, if the profile of the gear is constituted by an inner coating, the thickness of the inner coating is the thickness of the non-toothed portion, which is understood to mean the radial thickness from the bottom of the tooth to the surface of the core material of the formed gear profile.

The core material is 40Cr bar stock, and the outer diameter size of the selected bar stock is determined according to the size of the actually required gear. And (3) additive manufacturing of an inner coating on the surface of the bar by adopting a 3D printing technology, wherein the thickness of the inner coating is about 50mm (no gear teeth are calculated), and then polishing and flattening the inner coating surface to prepare a lower middle layer coating. And (3) performing additive manufacturing on the surface of the inner coating to obtain an intermediate coating, wherein the thickness of the intermediate coating is 30mm, and then polishing and flattening the surface of the intermediate coating to prepare an outer coating. And (3) performing additive manufacturing on the surface of the intermediate coating to form an inner coating, wherein the thickness of the inner coating is 20mm, and then polishing the surface of the inner coating to be flat, thereby finally manufacturing the required part.

The proportioning components of each coating are changed in a gradient manner, and the thickness is also set according to the gradient.

The wear-resistant and corrosion-resistant gradient coating formed in the scheme has the main advantages of high wear resistance, corrosion resistance, good toughness, strong binding force, difficult shedding and long service life.

The Ni-based self-fluxing alloy powder has good adaptability to various base materials, is easy to obtain a compact coating with low oxide content, smooth surface, low dilution rate, small porosity and easy metallurgical bonding with a matrix, and has good wettability, corrosion resistance and oxidation resistance. Meanwhile, the price is moderate and the cost performance is high.

The WC content in the inner coating is higher, so that the hardness of the inner coating is high, the toughness of the inner coating is optimal, and the working requirement of the gear in stable working is met.

The WC content in the intermediate coating is reduced, the WC can be well wetted by Ni metal melt, and the WC and Ni-based alloy powder can form composite powder to enhance the wear resistance of the surface of a metal material. In addition, CeO₂The addition of the tungsten carbide alloy can effectively improve the microstructure of a cladding layer, so that the shape of WC hard phase particles is improved and uniformly distributed in the coating, and the coating has the characteristics of metal toughness, good manufacturability, high hardness, wear resistance, corrosion resistance, oxidation resistance and the like of a ceramic material. The Mo material is high temperature resistant, corrosion resistant and wear resistant.

Mo is added into the outer coating, so that the wear resistance and corrosion resistance of the coating can be ensured, the wear rate is reduced under the working condition of seawater, and in addition, CeO₂The addition of the composite material can effectively improve the microstructure of the cladding layer, refine grains and improve the hardness and toughness of the coating.

The invention avoids the mutation of the organization and the performance from the matrix to the coating by controlling the gradient change of the components of each coating, improves the combination condition between the interfaces of the coatings, can further improve the bearing capacity and the wear resistance and the corrosion resistance of the coatings, and also meets the service requirement of the internal gear under special working conditions.

The foregoing embodiments are merely illustrative of the principles and utilities of the present invention and are not intended to limit the invention. Many modifications may be made to the present invention without departing from the spirit or scope of the general inventive concept, and it will be apparent to those skilled in the art that changes and modifications may be made to the above-described embodiments without departing from the spirit or scope of the invention. Accordingly, it is intended that all equivalent modifications or changes which can be made by those skilled in the art without departing from the spirit and technical spirit of the present invention be covered by the claims of the present invention.