阅读说明：本技术 一种金属3D打印用TiC颗粒增强铝合金粉末及其制备方法 (TiC particle reinforced aluminum alloy powder for metal 3D printing and preparation method thereof ) 是由 徐文雷 丁华 冯波 阳大云 袁成逸 冯雪桥 于 2021-09-16 设计创作，主要内容包括：本发明提供一种金属3D打印用TiC颗粒增强铝合金粉末及其制备方法,具体涉及金属增材制造技术领域。包括：制备Al-Ti-C预制块及铝合金基体配料；将铝合金基体配料熔化并升温至1200～1600℃,在惰性气体保护下加入Al-Ti-C预制块并搅拌,然后降温至1000～1200℃,得到含有TiC颗粒增强体的铝合金熔体；对含有TiC颗粒增强体的铝合金熔体进行气体雾化造粉,得到TiC颗粒增强铝合金粉末。本发明的金属3D打印用TiC颗粒增强铝合金粉末,TiC增强颗粒采用原位合成的方法形成于铝合金基体中,TiC增强颗粒与铝合金基体的界面结合强度高、无污染,可有效解决外加陶瓷颗粒与基体界面结合弱问题,同时可以细化选区激光熔化(SLM)3D打印后的组织,避免热裂纹的产生,提高铝合金的力学性能,满足高强度铝合金3D打印要求。(The invention provides TiC particle reinforced aluminum alloy powder for metal 3D printing and a preparation method thereof, and particularly relates to the technical field of metal additive manufacturing. The method comprises the following steps: preparing Al-Ti-C precast blocks and aluminum alloy matrix ingredients; melting the aluminum alloy matrix ingredients, heating to 1200-1600 ℃, adding the Al-Ti-C precast block under the protection of inert gas, stirring, and then cooling to 1000-1200 ℃ to obtain an aluminum alloy melt containing the TiC particle reinforcement; and carrying out gas atomization powder making on the aluminum alloy melt containing the TiC particle reinforcement to obtain TiC particle reinforced aluminum alloy powder. The TiC particles are formed in the aluminum alloy matrix by adopting an in-situ synthesis method, the interface bonding strength of the TiC reinforcing particles and the aluminum alloy matrix is high, no pollution is caused, the problem of weak bonding between the external ceramic particles and the matrix interface can be effectively solved, the structure of a 3D printed area by laser melting (SLM) can be refined, the generation of hot cracks is avoided, the mechanical property of the aluminum alloy is improved, and the 3D printing requirement of the high-strength aluminum alloy is met.)

1. A preparation method of TiC particle reinforced aluminum alloy powder for metal 3D printing is characterized by comprising the following steps:

preparing Al-Ti-C precast blocks and ingredients of an aluminum alloy matrix;

melting the aluminum alloy matrix with the prepared materials, heating to 1200-1600 ℃, adding the Al-Ti-C precast block under the protection of inert gas, standing until the fire light disappears, stirring, and cooling to 1000-1200 ℃ to obtain an aluminum alloy melt containing the TiC particle reinforcement;

and carrying out gas atomization powder making on the aluminum alloy melt containing the TiC particle reinforcement to obtain TiC particle reinforced aluminum alloy powder.

2. The method of claim 1, wherein the Al-Ti-C preform comprises a molar ratio of 1: 1: (0.5-1.0) Ti powder, graphite powder and Al powder.

3. A TiC particle reinforced aluminum alloy powder for metal 3D printing according to claim 2, wherein the Ti powder has a particle size of 200-320 meshes, the graphite powder has a particle size of 800-1200 meshes, and the Al powder has a particle size of 100-200 meshes.

4. The method of claim 1, wherein the aluminum alloy matrix comprises one or more of the following alloying elements in percentage by mass: 0.2-12% of Si, 0.2-8.0% of Mg, 0.1-1.0% of Mn, 0.2-8.0% of Cu and 0.20-9.0% of Zn.

5. A preparation method of TiC particle reinforced aluminum alloy powder for metal 3D printing according to claim 4, wherein the Cu element is added as an aluminum-copper intermediate alloy, the Si element is added as an aluminum-silicon intermediate alloy, the Mn element is added as an aluminum-manganese intermediate alloy, the Mg element is added as a pure magnesium ingot, and the Zn alloy is added as a pure zinc ingot.

6. The method of preparing TiC particle reinforced aluminum alloy powder for metal 3D printing according to claim 1, wherein the aluminum alloy matrix is melted by vacuum melting.

7. The method of claim 1, wherein the TiC particle-reinforced aluminum alloy powder is prepared by gas atomization of the TiC particle-reinforcement-containing aluminum alloy melt with argon gas.

8. The method of claim 1, further comprising screening the TiC particle-reinforced aluminum alloy powder.

9. A TiC particle-reinforced aluminum alloy powder, produced by the production method according to any one of claims 1 to 8.

10. A TiC particle reinforced aluminum alloy powder according to claim 9, wherein the TiC particle reinforcement is present in an amount of 1 to 6% by mass.

Technical Field

The invention relates to the technical field of metal additive manufacturing, in particular to TiC particle reinforced aluminum alloy powder for metal 3D printing and a preparation method thereof.

Background

The additive manufacturing technology (also called 3D printing technology) is based on a three-dimensional design model designed in advance by a computer, the model is sliced and layered through computer software, then printing materials are overlapped layer by layer according to slice graphs and finally stacked into a complete entity, and the method is one of key core technologies in the field of intelligent manufacturing. The method has the advantages of high forming speed, unconstrained structural design, capability of realizing complex structural parts which are difficult to manufacture by the traditional processing method, high material utilization rate, reduction of processing procedures, shortening of processing period and the like, and is widely applied to the fields of automobile manufacturing, mold and tool clamp processing, aerospace, medical appliances and the like at present.

The aluminum alloy has the advantages of low density, high specific strength and specific modulus, corrosion resistance, good heat conductivity and the like, and has become a light alloy powder material widely applied in the field of 3D printing, but the currently commonly used 3D printing aluminum alloy powder such as AlSi12, AlSi10Mg, AlSi7Mg and other varieties has the defects of low mechanical strength, unsatisfactory high-temperature performance and the like, and can not meet the printing requirements of high-strength parts. Although a lot of high-strength aluminum alloy materials exist at present, the high-strength aluminum alloy materials are generally used for preparing aluminum alloy sections, and the high-strength aluminum alloy materials are directly used for 3D printing materials, and because the temperature range of the solidification interval is wide, thick columnar crystals are easily formed and thermal cracks are easily generated due to rapid melting and solidification in the Selective Laser Melting (SLM)3D printing process, the popularization and application of the high-strength aluminum alloy in the SLM3D printing field are directly limited, and therefore, the development of high-strength aluminum alloy powder suitable for SLM3D printing becomes a difficult problem to be solved urgently.

In order to solve the problems of easy heat cracking and the like in SLM3D printing of high-strength aluminum alloy, a plurality of research structures at home and abroad are widely researched, and the following four technical routes exist at present.

1) Specially-developed 3D printing Scalmalloy high-strength aluminum alloy powder by Airbus and APWORKS, wherein the alloy component system is Al-Mg-Sc-Zr, and Al is formed in a melt in the 3D printing process₃The (Sc/Zr) particles are used as heterogeneous nucleating agents to refine the solidification structure of the aluminum alloy during rapid solidification, thereby avoiding the generation of thermal cracks and improving the strength and the plasticity of the aluminum alloy. However, the global reserve of the rare earth element Sc is small, the price is high, the commercial application of the Sc is limited, and the Sc is mainly applied to the fields of aerospace, super sports cars and the like at present.

2) Nanometer ZrH is introduced into Al7075 powder by HRL laboratory of university of California in America through electrostatic assembly technology₂The problem of heat cracking is solved by refining the matrix structure with particles, but the mechanical properties are low due to the existence of more pores in the part during the forming process.

3) TiB in titanium boride particle reinforced aluminum alloy powder for additive manufacturing (GB/T38972-₂The particle reinforced aluminum alloy powder is mainly manufactured by a molten salt method, so that more molten slag is generated in the smelting process, the slag is difficult to completely remove, and the molten slag residue is easy to generate in parts after 3D printing is completed, so that the performance of the aluminum alloy is reduced.

4) Grinding the nano-ceramic particles (such as SiC and TiB) by ball milling₂TiC, etc.) into the aluminum alloy powder for 3D printing to enhance the comprehensive performance of the aluminum alloy part.However, the nano particles have huge specific surface area, so that the particle agglomeration phenomenon is easily caused, and the mechanical property of the material is reduced; meanwhile, the aluminum alloy and the nano ceramic particles have poor interface wettability and low interface bonding strength, and are easy to crack in the service process of parts so as to fail in advance.

Although the above technical routes have made certain breakthrough in the research and application of high-strength 3D printing aluminum alloy powder, the above technical routes have their own defects and shortcomings.

Disclosure of Invention

In view of the defects of the prior art, the invention aims to provide a preparation method of novel TiC particle reinforced aluminum alloy powder for metal 3D printing, TiC reinforced particles are synthesized in an aluminum alloy melt in situ, an aluminum alloy matrix and the TiC reinforced particles are well combined in an interface and have a refined structure, and the problem of heat cracking of high-strength aluminum alloy in the 3D printing process is effectively solved.

In order to achieve the above objects and other related objects, the present invention provides the following technical solutions: a preparation method of TiC particle reinforced aluminum alloy powder for metal 3D printing comprises the following steps:

s1, preparing Al-Ti-C precast blocks and ingredients of an aluminum alloy matrix;

s2, melting the aluminum alloy matrix of the prepared material, heating to 1200-1600 ℃, adding the Al-Ti-C precast block under the protection of inert gas, standing until the fire disappears, stirring, and cooling to 1000-1200 ℃ to obtain an aluminum alloy melt containing the TiC particle reinforcement;

s3, carrying out gas atomization powder making on the aluminum alloy melt containing the TiC particle reinforcement to obtain TiC particle reinforced aluminum alloy powder.

In some embodiments of the invention, the Al-Ti-C preform comprises a molar ratio of 1: 1: (0.5-1.0) Ti powder, graphite powder and Al powder.

In some embodiments of the present invention, the Ti powder has a particle size of 200 to 320 mesh, the graphite powder has a particle size of 800 to 1200 mesh, and the Al powder has a particle size of 100 to 200 mesh.

In some embodiments of the present invention, the aluminum alloy matrix comprises one or more of the following alloying elements in percentage by mass: 0.2-12% of Si, 0.2-8.0% of Mg, 0.1-1.0% of Mn, 0.2-8.0% of Cu and 0.20-9.0% of Zn.

In some embodiments of the present invention, the Cu element is added as an aluminum-copper master alloy, the Si element is added as an aluminum-silicon master alloy, the Mn element is added as an aluminum-manganese master alloy, the Mg element is added as a pure magnesium ingot, and the Zn element is added as a pure zinc ingot.

In some embodiments of the invention, the aluminum alloy substrate is melted by vacuum melting.

In some embodiments of the invention, the TiC particle reinforcement-containing aluminum alloy melt is gas atomized to produce powder by argon.

In some embodiments of the invention, further comprising sieving the TiC particulate reinforced aluminum alloy powder.

In another aspect, the present invention also provides a TiC particle reinforced aluminum alloy powder prepared according to the preparation method as described above.

In some embodiments of the invention, the TiC particle reinforcement is 1-6% by mass.

Compared with the prior art, the invention has the following partial beneficial effects:

firstly, TiC reinforced particles grow in situ in an aluminum alloy melt by an in-situ synthesis method, the interface bonding strength of the TiC reinforced particles and an aluminum alloy matrix is high, no pollution is caused, and the problem of weak bonding between external ceramic particles and the matrix interface can be effectively solved; secondly, the invention adopts one-time vacuum melting, has less slag, easy removal, high material utilization rate and low cost, and is suitable for large-scale production; in addition, the TiC particle reinforced aluminum alloy powder for 3D printing prepared by the invention is synthesized in situ, and micro-nano TiC particles formed in the SLM3D printing process can be used as heterogeneous nucleating agents, so that the structure is effectively refined, the phenomenon of heat cracking is avoided, and the strength and the plasticity of the material are improved; in addition, the TiC particle reinforced aluminum alloy powder for 3D printing prepared by the invention can adjust the mechanical property of the material by adjusting the content of TiC particles, and meets the requirements of 3D printing performance of different parts.

The advantageous effects of the present invention are not limited to this, and other advantages are described in detail in the embodiment section of the specification.

Detailed Description

The embodiments of the present invention are described below with reference to specific embodiments, and other advantages and effects of the present invention will be easily understood by those skilled in the art from the disclosure of the present specification. The invention is capable of other and different embodiments and of being practiced or of being carried out in various ways, and its several details are capable of modification in various respects, all without departing from the spirit and scope of the present invention. It is to be noted that the features in the following embodiments and examples may be combined with each other without conflict. It is also to be understood that the terminology used in the examples is for the purpose of describing particular embodiments only, and is not intended to limit the scope of the present invention. Test methods in which specific conditions are not specified in the following examples are generally carried out under conventional conditions or under conditions recommended by the respective manufacturers.

When numerical ranges are given in the examples, it is understood that both endpoints of each of the numerical ranges and any value therebetween can be selected unless the invention otherwise indicated. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs and the description of the present invention, and any methods, apparatuses, and materials similar or equivalent to those described in the examples of the present invention may be used to practice the present invention.

The invention provides a preparation method of TiC particle reinforced aluminum alloy powder for metal 3D printing, which comprises the following steps:

s1, preparing Al-Ti-C precast blocks and ingredients of an aluminum alloy matrix;

s2, melting the aluminum alloy matrix of the prepared material, heating to 1200-1600 ℃, adding the Al-Ti-C precast block under the protection of inert gas, standing until the fire disappears, stirring, and cooling to 1000-1200 ℃ to obtain an aluminum alloy melt containing the TiC particle reinforcement;

s3, carrying out gas atomization powder making on the aluminum alloy melt containing the TiC particle reinforcement to obtain TiC particle reinforced aluminum alloy powder.

In an embodiment, in step S1, the Al-Ti-C precast block includes Ti powder, graphite powder, and Al powder, and the molar ratio of the Ti powder to the graphite powder is, for example, 1: 1: (0.5 to 1.0). The Al-Ti-C prefabricated block is prepared, for example, by mixing Ti powder, graphite powder and Al powder in a molar ratio, mechanically mixing, and compacting into a block. Wherein, the granularity of Ti powder can be 200-320 meshes, the granularity of graphite powder can be 800-1200 meshes, and the granularity of Al powder can be 100-200 meshes.

In a specific embodiment, the aluminum alloy substrate in step S1 may be an aluminum alloy substrate including one or more alloying elements, for example, one or more of the following alloying elements may be included in the aluminum alloy substrate in percentage by mass: for example, the alloy contains 0.2 to 12% of Si element, for example, 0.2 to 8.0% of Mg element, for example, 0.1 to 1.0% of Mn element, for example, 0.2 to 8.0% of Cu element, for example, 0.2 to 9.0% of Zn element, and the like, and may contain other elements. In the aluminum alloy matrix, Cu element is added in the form of aluminum-copper intermediate alloy; si element is added in the form of aluminum-silicon intermediate alloy; mn element is added in the form of aluminum-manganese intermediate alloy; mg element is added in the form of pure metal magnesium ingot; zn element is added in the form of pure metal zinc ingot. When the aluminum alloy matrix is prepared according to alloy components, the burning loss rate of each alloy element needs to be considered.

In a specific embodiment, the specific process of step S2 is, for example, to weigh the Al-Ti-C precast block according to the mass percentage of the TiC particle reinforcement in the TiC particle reinforced aluminum alloy powder being 1-6%. Then, the aluminum-silicon intermediate alloy, the aluminum-manganese intermediate alloy, the aluminum-copper intermediate alloy and the metallic aluminum which are proportioned in the step 1 are put into a smelting furnace for smelting, such as a vacuum smelting furnace, more specifically, a vacuum induction smelting furnace. After the aluminum alloy matrix is melted, heating to 1200-1600 ℃, adding an Al-Ti-C precast block under the protection of inert gas such as argon, heating the Al-Ti-C precast block to react and emit white flame, standing for a period of time, stirring and beginning to cool after the flame disappears, and when the temperature is reduced to 1000-1200 ℃, adding the metal magnesium and the metal zinc which are well proportioned and standing for a period of time to obtain the aluminum alloy melt containing the TiC particle reinforcement. The stirring of the aluminum alloy melt is for example electromagnetic stirring, so that TiC particles can be better dispersed in the aluminum alloy melt, and the problem of agglomeration of the TiC particles is effectively relieved.

In one embodiment, in step S3, the aluminum alloy melt containing TiC particle reinforcement may be subjected to gas atomization and powdering using argon gas, for example, at a pressure of 1 MPa. The specific process of gas atomization powder making is, for example, conveying an aluminum alloy melt containing a TiC particle reinforcement to a conduit, introducing the aluminum alloy melt into an atomization system, and then atomizing and cooling the melt by using argon under the atomization pressure of 1MPa to obtain TiC particle reinforcement aluminum alloy powder. The TiC particle reinforced aluminum alloy powder obtained under the atomization condition has good sphericity and uniform powder particle size distribution.

In a specific embodiment, the method further includes step S4, screening the TiC particle reinforced aluminum alloy powder. The purpose of screening is in order to screen out the TiC granule reinforcing aluminum alloy powder of suitable particle size, makes it more be applicable to SLM3D and prints. The screening can be accomplished by, for example, twice screening, and screens with different apertures are selected for twice screening, so that the TiC particle reinforced aluminum alloy powder in the required particle size range can be screened out. For example, the aperture of the screen mesh for the first screening is 15 microns, powder with the particle size smaller than 15 microns is screened out, the aperture of the screen mesh for the second screening is 53 microns, powder with the particle size larger than 53 microns is screened out, and the TiC particle reinforced aluminum alloy powder with the particle size between 15 microns and 53 microns is obtained through twice screening, wherein the TiC particle reinforced aluminum alloy powder with the particle size meets the SLM3D printing requirement. Meanwhile, aluminum alloy powder in other particle size ranges can be screened according to the requirements of SLM3D printing equipment.

The invention will now be described by way of the following examples.

Example 1

The TiC particle reinforced aluminum alloy powder A for metal 3D printing is prepared by the following steps:

(1) preparation of Al-Ti-C precast block

Mixing Ti powder, graphite powder and Al powder according to a molar ratio of 1: 1: 1, preparing materials, wherein the granularity of Ti powder is 200-320 meshes, the granularity of graphite powder is 800-1200 meshes, and the granularity of aluminum powder is 100-200 meshes, and then, uniformly mixing by a mechanical method and compacting into blocks for later use.

(2) Ingredients

The elements are mixed according to the following mass percentage: 4.5 wt% of Cu, 0.8 wt% of Si, 0.6 wt% of Mg, 0.6 wt% of Mn, 1.0 wt% of reinforcing body TiC (added in a way of Al-Ti-C precast block), and the balance of Al. Wherein, Cu, Si and Mn are respectively proportioned in the forms of aluminum-copper intermediate alloy, aluminum-silicon intermediate alloy and aluminum-manganese intermediate alloy, and magnesium and aluminum are respectively proportioned in the forms of pure magnesium and pure aluminum. And calculating the required amounts of the aluminum-copper intermediate alloy, the aluminum-silicon intermediate alloy, the aluminum-manganese intermediate alloy, the pure magnesium, the pure aluminum and the Al-Ti-C precast block, and then weighing for later use.

(3) Melting

Vacuum medium-frequency induction melting is adopted, the preset vacuum degree is 3Pa, weighed aluminum ingots, aluminum-silicon intermediate alloy, aluminum-copper intermediate alloy and aluminum-manganese intermediate alloy are sequentially added, melting is carried out under the condition of argon protection, aluminum alloy matrix melt is obtained, then the temperature is raised to 1300 ℃, Al-Ti-C precast blocks are added into the melt, the precast blocks are heated to react, TiC particles are synthesized in situ in the aluminum alloy matrix, white fire light is emitted, electromagnetic stirring is carried out after the fire light disappears, the temperature is reduced to 1000 ℃, pure magnesium ingots are added, and slag is removed after standing for 20min, so that the aluminum alloy melt containing TiC particle reinforcement is obtained.

(4) Gas atomization powder making

And (3) conveying the aluminum alloy melt containing the TiC particle reinforcement to a guide pipe, introducing the aluminum alloy melt into an atomization system, and carrying out atomization cooling on the melt by adopting argon at the atomization pressure of 1MPa to obtain TiC particle reinforced aluminum alloy powder.

(5) Sieving

And (3) screening the TiC particle reinforced aluminum alloy powder, wherein the aperture of the screen mesh screened for the first time is 15 micrometers, and the aperture of the screen mesh screened for the second time is 53 micrometers, so as to obtain the TiC particle reinforced aluminum alloy powder A for 3D printing, which is synthesized in situ and has the particle size of 15-53 micrometers.

Example 2

The TiC particle reinforced aluminum alloy powder B for metal 3D printing is prepared by the following steps:

(1) preparation of Al-Ti-C precast block

Mixing Ti powder, graphite powder and Al powder according to a molar ratio of 1: 1: 1, preparing materials, wherein the granularity of Ti powder is 200-320 meshes, the granularity of graphite powder is 800-1200 meshes, and the granularity of aluminum powder is 100-200 meshes, and then, uniformly mixing by a mechanical method and compacting into blocks for later use.

(2) Ingredients

The elements are mixed according to the following mass percentage: 4.5 wt% of Cu, 0.8 wt% of Si, 0.6 wt% of Mg, 0.6 wt% of Mn, 2.0 wt% of reinforcing body TiC (added in a way of Al-Ti-C precast block), and the balance of Al. Wherein Cu is added as an aluminum-copper intermediate alloy, Si is added as an aluminum-silicon intermediate alloy, Mn is added as an aluminum-manganese intermediate alloy, and magnesium is added as a pure magnesium ingot. Calculating the amount of the needed aluminum-copper intermediate alloy, aluminum-silicon intermediate alloy, aluminum-manganese intermediate alloy, magnesium ingot, aluminum ingot and Al-Ti-C precast block, and then weighing for later use.

(3) Melting

Vacuum medium-frequency induction melting is adopted, the preset vacuum degree is 3Pa, weighed aluminum ingots, aluminum-silicon intermediate alloy, aluminum-copper intermediate alloy and aluminum-manganese intermediate alloy are sequentially added, melting is carried out under the condition of argon protection, aluminum alloy matrix melt is obtained, then the temperature is raised to 1300 ℃, Al-Ti-C precast blocks are added into the melt, the precast blocks are heated to react, TiC particles are synthesized in situ in the aluminum alloy matrix, white fire light is emitted, electromagnetic stirring is carried out after the fire light disappears, the temperature is reduced to 1000 ℃, pure magnesium ingots are added, and slag is removed after standing for 20min, so that the aluminum alloy melt containing TiC particle reinforcement is obtained.

(4) Gas atomization powder making

And (3) conveying the aluminum alloy melt containing the TiC particle reinforcement to a guide pipe, introducing the aluminum alloy melt into an atomization system, and carrying out atomization cooling on the melt by adopting argon at the atomization pressure of 1MPa to obtain TiC particle reinforced aluminum alloy powder.

(5) Sieving

And (3) screening the TiC particle reinforced aluminum alloy powder, wherein the aperture of the screen mesh screened for the first time is 15 micrometers, and the aperture of the screen mesh screened for the second time is 53 micrometers, so as to obtain the TiC particle reinforced aluminum alloy powder B for 3D printing, which is synthesized in situ and has the particle size of 15-53 micrometers.

Example 3

The TiC particle reinforced aluminum alloy powder C for metal 3D printing is prepared by the following steps:

(1) preparation of Al-Ti-C precast block

Mixing Ti powder, graphite powder and Al powder according to a molar ratio of 1: 1: 1, preparing materials, wherein the granularity of Ti powder is 200-320 meshes, the granularity of graphite powder is 800-1200 meshes, and the granularity of aluminum powder is 100-200 meshes, and then, uniformly mixing by a mechanical method and compacting into blocks for later use.

(2) Ingredients

The elements are mixed according to the following mass percentage: 4.5 wt% of Cu, 0.8 wt% of Si, 0.6 wt% of Mg, 0.6 wt% of Mn, 3.0 wt% of reinforcing body TiC (added in a way of Al-Ti-C precast block), and the balance of Al. Wherein Cu is added as an aluminum-copper intermediate alloy, Si is added as an aluminum-silicon intermediate alloy, Mn is added as an aluminum-manganese intermediate alloy, and magnesium is added as a pure magnesium ingot. Calculating the amount of the needed aluminum-copper intermediate alloy, aluminum-silicon intermediate alloy, aluminum-manganese intermediate alloy, magnesium ingot, aluminum ingot and Al-Ti-C precast block, and then weighing for later use.

(3) Melting

Vacuum medium-frequency induction melting is adopted, the preset vacuum degree is 3Pa, weighed aluminum ingots, aluminum-silicon intermediate alloy, aluminum-copper intermediate alloy and aluminum-manganese intermediate alloy are sequentially added, melting is carried out under the condition of argon protection, aluminum alloy matrix melt is obtained, then the temperature is raised to 1300 ℃, Al-Ti-C precast blocks are added into the melt, the precast blocks are heated to react, TiC particles are synthesized in situ in the aluminum alloy matrix, white fire light is emitted, electromagnetic stirring is carried out after the fire light disappears, the temperature is reduced to 1000 ℃, pure magnesium ingots are added, and slag is removed after standing for 20min, so that the aluminum alloy melt containing TiC particle reinforcement is obtained.

(4) Gas atomization powder making

And (3) conveying the aluminum alloy melt containing the TiC particle reinforcement to a guide pipe, introducing the aluminum alloy melt into an atomization system, and carrying out atomization cooling on the melt by adopting argon at the atomization pressure of 1MPa to obtain TiC particle reinforced aluminum alloy powder.

(5) Sieving

And (3) screening the TiC particle reinforced aluminum alloy powder, wherein the aperture of the screen mesh screened for the first time is 15 micrometers, and the aperture of the screen mesh screened for the second time is 53 micrometers, so as to obtain the TiC particle reinforced aluminum alloy powder C for 3D printing, which is synthesized in situ and has the particle size of 15-53 micrometers.

Comparative example

The preparation method of the aluminum alloy powder D for metal 3D printing comprises the following steps:

(1) ingredients

The elements are mixed according to the following mass percentage: 4.5 wt% Cu, 0.8 wt% Si, 0.6 wt% Mg, 0.6 wt% Mn, and the balance Al. Wherein Cu is added as an aluminum-copper intermediate alloy, Si is added as an aluminum-silicon intermediate alloy, Mn is added as an aluminum-manganese intermediate alloy, and magnesium is added as a pure magnesium ingot. Calculating the amount of the needed aluminum-copper intermediate alloy, aluminum-silicon intermediate alloy, aluminum-manganese intermediate alloy, magnesium ingot and aluminum ingot, and then weighing for later use.

(2) Melting

Vacuum medium-frequency induction melting is adopted, the preset vacuum degree is 3Pa, weighed aluminum ingots, aluminum-silicon intermediate alloy, aluminum-copper intermediate alloy and aluminum-manganese intermediate alloy are sequentially added, melting is carried out under the condition of argon protection, aluminum alloy matrix melt is obtained, then electromagnetic stirring is carried out, the temperature is reduced to 1000 ℃, pure magnesium ingots are added, standing is carried out for 20min, and slag is removed, so that the aluminum alloy melt is obtained.

(3) Gas atomization powder making

And conveying the aluminum alloy melt to a guide pipe, introducing the aluminum alloy melt into an atomization system, and carrying out atomization cooling on the melt by adopting argon at the atomization pressure of 1MPa to obtain aluminum alloy powder.

(4) Sieving

And (3) screening the aluminum alloy powder, wherein the aperture of the screen for the first screening is 15 micrometers, and the aperture of the screen for the second screening is 53 micrometers, so as to obtain the aluminum alloy powder D for 3D printing with the particle size of 15-53 micrometers.

Performance testing

The TiC particle reinforced aluminum alloy powder prepared in the embodiments 1-3 and the aluminum alloy powder obtained in the comparative example are subjected to sample printing on Selective Laser Melting (SLM)3D printing equipment by using appropriate printing parameters, are processed into tensile test bars after T6 heat treatment, and are subjected to mechanical property test according to the GB/T228-.

Table 13D mechanical property test of printed tensile test bars

As can be seen from Table 1, the tensile strength of the in-situ synthesized TiC particle-reinforced aluminum alloy powder A-C after 3D printing is 452-564 MPa, the yield strength is 412-527 MPa, and the elongation after fracture is 10.5-16.5%, and the strength is further improved with the increase of the addition amount of TiC particles, but the elongation after fracture is reduced, but the mechanical property data are superior to the 3D printing mechanical property of the comparative aluminum alloy powder D.

In conclusion, the TiC reinforced particles grow in situ in the aluminum alloy melt by the in-situ synthesis method, the interface bonding strength of the TiC reinforced particles and the aluminum alloy matrix is high, no pollution is caused, and the problem of weak bonding between the external ceramic particles and the matrix interface can be effectively solved; secondly, the invention adopts one-time vacuum melting, has less slag, easy removal, high material utilization rate and low cost, and is suitable for large-scale production; moreover, the TiC particle reinforced aluminum alloy powder for 3D printing prepared by the invention is synthesized in situ, and micro-nano TiC particles formed in the SLM3D printing process can be used as heterogeneous nucleating agents, so that the structure is effectively refined, the phenomenon of thermal cracking is avoided, and the strength and the plasticity of the material are improved; in addition, the TiC particle reinforced aluminum alloy powder for 3D printing prepared by the invention can adjust the mechanical property of the material by adjusting the content of TiC particles, and meets the requirements of 3D printing performance of different parts.

The foregoing embodiments are merely illustrative of the principles and utilities of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or change the above-mentioned embodiments without departing from the spirit and scope of the present 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.