Copper-based superalloy / cobalt-based superalloy heterogeneous composite material and preparation method thereof

Abstract

The invention discloses a copper-based high-temperature alloy / cobalt-based high-temperature alloy heterogeneous composite material and a preparation method thereof, and belongs to the technical field of heterogeneous alloy materials. According to the preparation method, the copper-based high-temperature alloy powder and the cobalt-based high-temperature alloy powder serve as raw materials, the copper-based high-temperature alloy / cobalt-based high-temperature alloy heterogeneous composite material is prepared through the laser powder bed melting technology, and compared with traditional preparation technologies such as friction stir welding and a hot rolling method, die-free manufacturing and direct manufacturing of parts with complex sizes can be achieved; and particularly, accurate regulation and control of components and structures can be achieved for forming of heterogeneous composite material interface joints, the related production period is short, the raw material utilization rate is increased, and the method is suitable for application and popularization.

Description

Technical Field

[0001] The present invention belongs to the technical field of heterogeneous alloy materials, and in particular relates to a copper-based high-temperature alloy / cobalt-based high-temperature alloy heterogeneous composite material and a preparation method thereof. Background Art

[0002] Complex working conditions such as aerospace and nuclear reactors that require both high strength and high thermal conductivity place extremely high demands on the performance of the materials used. In such harsh environments, traditional homogeneous materials usually cannot meet all performance requirements. Therefore, multi-metal structures composed of two or more metals have important application value in such complex working conditions. Heterogeneous alloy materials are composite materials that combine multiple metals with excellent performance. Because this material effectively combines the performance advantages of different metals and improves the various performances of key components at the same time. It is widely used in aerospace, transportation, automobiles, military and other fields. At present, heterogeneous alloys can be made by many traditional methods, such as stir friction welding, hot rolling, and chemical vapor deposition. However, the additive manufacturing method of layer-by-layer printing has attracted much attention because it can prepare larger heterogeneous alloy materials in a shorter time. Laser powder bed melting technology has the advantage of simple powder spreading and high molding accuracy in the preparation of heterogeneous alloys. Therefore, by changing the type of powder for powder spreading, laser powder bed melting technology can be used to quickly prepare heterogeneous alloy materials. At the same time, for the printing of parts with complex structures, laser powder bed melting technology can accurately adjust the printing position to achieve on-demand precision manufacturing.

[0003] Liquid rocket engines and aero engines play an irreplaceable role in modern aerospace and aerospace engineering, providing key power support for space exploration, satellite launches and flight missions. The combustion chamber is the core component of this type of high-performance engine. The materials required for these engines must have multiple properties at the same time, including high-temperature strength, high-temperature oxidation resistance, corrosion resistance, high thermal conductivity and mechanical toughness. Copper alloys are known for their high thermal conductivity and excellent heat dissipation performance, which helps to quickly conduct and dissipate heat. Cobalt-based alloys have excellent thermal stability and high-temperature resistance, and can effectively serve at high temperatures. The combination of these two alloys can give full play to the advantages of their respective characteristics. Copper-based alloys are responsible for the rapid conduction of the generated heat, while cobalt-based alloys bear the mechanical properties under long-term high-temperature environments. In this study, laser powder bed melting technology was used to use an optimized process to suppress the segregation of carbon elements at the interface, thereby reducing cracks at the interface, and realizing the macro-defect-free additive manufacturing of copper-based and cobalt-based alloy heterogeneous composites, and a copper-based high-temperature alloy / cobalt-based high-temperature alloy heterogeneous composite with excellent performance was obtained. Summary of the invention

[0004] The purpose of this section is to summarize some aspects of embodiments of the present invention and briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this section and the specification abstract and the invention title of this application to avoid blurring the purpose of this section, the specification abstract and the invention title, and such simplifications or omissions cannot be used to limit the scope of the present invention.

[0005] In view of the problems existing in the prior art, the present invention is proposed, which specifically relates to a copper-based high-temperature alloy / cobalt-based high-temperature alloy heterogeneous composite material based on laser powder bed melting technology and a preparation method thereof. The invention realizes macro-defect-free additive manufacturing of copper-based and cobalt-based alloy heterogeneous composite materials, and obtains copper-based high-temperature alloy / cobalt-based high-temperature alloy heterogeneous composite materials with excellent performance.

[0006] In view of the above problems and / or the problems existing in the prior art, the present invention is proposed.

[0007] Therefore, the purpose of the present invention is to overcome the deficiencies in the prior art and provide a method for preparing a copper-based high-temperature alloy / cobalt-based high-temperature alloy heterogeneous composite material.

[0008] In order to solve the above technical problems, the present invention provides the following technical solutions: comprising:

[0009] Laser powder bed melting technology is used to spread powder and preheat the substrate. In a protective atmosphere, copper-based high-temperature alloy spherical powder is used as raw material to print a copper-based high-temperature alloy layer on the surface of the substrate.

[0010] Then, the powder is replaced, the powder is re-spread, and the powder is preheated. In a protective atmosphere, the cobalt-based superalloy spherical powder is used as a raw material to print the cobalt-based superalloy layer A at the interface of the copper-based superalloy / cobalt-based superalloy;

[0011] Then, a cobalt-based high-temperature alloy layer B is printed; that is, a copper-based high-temperature alloy / cobalt-based high-temperature alloy heterogeneous composite material is obtained;

[0012] Wherein, the number of layers of the cobalt-based high-temperature alloy layer A is 10 to 30.

[0013] As a preferred solution of the method for preparing the copper-based high-temperature alloy / cobalt-based high-temperature alloy heterogeneous composite material described in the present invention, the copper-based high-temperature alloy includes one or more of GRCop-42 and GRCop-84.

[0014] As a preferred solution of the method for preparing the copper-based high-temperature alloy / cobalt-based high-temperature alloy heterogeneous composite material described in the present invention, the cobalt-based high-temperature alloy includes one or more of GH5188 and GH5606.

[0015] As a preferred solution of the method for preparing the copper-based high-temperature alloy / cobalt-based high-temperature alloy heterogeneous composite material described in the present invention, the copper-based high-temperature alloy powder and the cobalt-based high-temperature alloy powder are both micron-sized spherical powders.

[0016] As a preferred solution of the method for preparing the copper-based high-temperature alloy / cobalt-based high-temperature alloy heterogeneous composite material described in the present invention, the protective atmosphere includes one or more of argon and nitrogen.

[0017] As a preferred scheme for the preparation method of the copper-based high-temperature alloy / cobalt-based high-temperature alloy heterogeneous composite material described in the present invention, the process parameters of the laser powder bed melting used for the copper-based high-temperature alloy layer are: laser power of 340-370W, scanning rate of 650-900mm / s, printing spacing of 100μm, layer thickness of 30μm, and rotation of each layer by 67°.

[0018] As a preferred scheme for the preparation method of the copper-based high-temperature alloy / cobalt-based high-temperature alloy heterogeneous composite material described in the present invention, the process parameters of the laser powder bed melting used for the cobalt-based high-temperature alloy layer A are: laser power of 290-350W, scanning rate of 900-1400mm / s, printing spacing of 100μm, layer thickness of 30μm, and each layer rotated 67°.

[0019] As a preferred scheme for the preparation method of the copper-based high-temperature alloy / cobalt-based high-temperature alloy heterogeneous composite material described in the present invention, the process parameters of the laser powder bed melting used for the cobalt-based high-temperature alloy layer B are: laser power of 230-260W, scanning rate of 650-900mm / s, printing spacing of 100μm, layer thickness of 30μm, and rotation of each layer by 67°.

[0020] As a preferred solution of the method for preparing the copper-based high-temperature alloy / cobalt-based high-temperature alloy heterogeneous composite material described in the present invention, wherein: the substrate comprises a cobalt-based high-temperature alloy.

[0021] Another object of the present invention is to overcome the deficiencies in the prior art and provide a copper-based high-temperature alloy / cobalt-based high-temperature alloy heterogeneous composite material. Starting from the substrate, it includes, in sequence,

[0022] Copper-based high-temperature alloy layer;

[0023] Cobalt-based superalloy layer A at the copper-based superalloy / cobalt-based superalloy interface;

[0024] Cobalt-based high-temperature alloy layer B;

[0025] The number of the copper-based high-temperature alloy layers is equal to the number of the cobalt-based high-temperature alloy layers, and the number of the cobalt-based high-temperature alloy layers A is 10 to 30.

[0026] Beneficial effects of the present invention:

[0027] (1) The present invention uses copper-based high-temperature alloy powder and cobalt-based high-temperature alloy powder as raw materials, and prepares copper-based high-temperature alloy / cobalt-based high-temperature alloy heterogeneous composite materials through laser powder bed melting technology. Compared with traditional preparation processes such as stir friction welding and hot rolling, the present invention can realize moldless manufacturing and direct manufacturing of large and small complex parts; in particular, the molding of the interface connection of the heterogeneous composite material can realize precise control of the composition and structure, and the production cycle involved is short, the raw material utilization rate is improved, and it is suitable for promotion and application.

[0028] (2) The copper-based high-temperature alloy / cobalt-based high-temperature alloy heterogeneous composite material prepared by the present invention preferably uses a cobalt alloy that exhibits better stress fracture performance under long time and high temperature.

[0029] (3) When printing the first X layers of cobalt-based high-temperature alloy layers (10≤X≤30) at the interface of the copper-based high-temperature alloy / cobalt-based high-temperature alloy heterogeneous composite material prepared by the present invention, the segregation of carbon elements at the interface is suppressed by effectively controlling the process parameters, thereby reducing the generation of cracks at the interface, thereby achieving macro-defect-free additive manufacturing of copper-based and cobalt-based alloy composite materials with large physical property differences. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work. Among them:

[0031] Figure 1 Schematic diagram of the structure of the copper-based high-temperature alloy / cobalt-based high-temperature alloy heterogeneous composite material prepared in Example 1

[0032] Figure 2 This is a microhardness distribution diagram of the copper-based high-temperature alloy / cobalt-based high-temperature alloy heterogeneous composite material prepared in Example 1;

[0033] Figure 3 This is a picture of the heterogeneous grain morphology of the copper-based high-temperature alloy / cobalt-based high-temperature alloy heterogeneous composite material prepared in Examples 1 to 6.

[0034] Figure 4 The engineering stress-strain curves of the copper-based high-temperature alloy / cobalt-based high-temperature alloy heterogeneous composite materials prepared in Examples 1 to 6 are shown. DETAILED DESCRIPTION

[0035] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the embodiments of the specification.

[0036] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0037] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The term "in one embodiment" that appears in different places in this specification does not necessarily refer to the same embodiment, nor is it a separate or selective embodiment that is mutually exclusive with other embodiments.

[0038] The raw materials used in the present invention are all commercially available unless otherwise specified.

[0039] The laser powder bed melting step of the present invention adopts the EOS M290 3D printer provided by the German EOS company, which is equipped with a Yb fiber laser and a powder forming system, including functional units such as a building cabin, a powder movement mechanism, and a powder bar. According to the provisions of GB / T10623-2008 on the terminology of mechanical properties of metal materials, the tensile sample processing is based on the standard of ASTM-E8, and a 50kN universal tensile testing machine (Instron 5966) is used for tensile testing, equipped with a video extensometer, and the loading rate is 10 -3 / s.

[0040] Example 1

[0041] This embodiment provides a method for preparing a copper-based high-temperature alloy / cobalt-based high-temperature alloy heterogeneous composite material, and its structural schematic diagram is shown in Figure 1 , specifically:

[0042] 1) The size is 150×150×10cm 3 The rolled GH5188 cobalt-based alloy plate was used as the substrate. The surface of the substrate was first polished with sandpaper, and then the surface oil stains were cleaned with anhydrous ethanol.

[0043] 2) The building cabin was filled with high-purity argon (<1000ppm) to prevent oxidation of the sample during the printing process; GRCop-42 copper-based high-temperature alloy powder with an average particle size of 15 to 53μm was weighed and put into the powder tank; the laser power of the laser powder bed melting equipment was adjusted to 370W and the scanning rate was 650mm / s. A high-power continuous wave laser beam formed a molten pool on the substrate, and the powder was quickly melted and solidified to deposit 175 layers (of the same composition) of GRCop-42 copper-based high-temperature alloy on the cobalt-based high-temperature alloy substrate (GH5188).

[0044] 3) Put GH5188 cobalt-based high-temperature alloy powder with an average particle size of 15 to 53 μm into the powder cylinder, re-spread the powder, preheat the substrate, set the laser power to 320 W, the scanning power to 1150 mm / s, and print the first 20 layers of cobalt-based high-temperature alloy at the interface.

[0045] 4) Set the laser power to 260 mm / s and the scanning rate to 650 mm / s to print the remaining 155 layers (with the same composition) of GH5188 cobalt-based high-temperature alloy.

[0046] In this embodiment, a total of 350 layers of samples are deposited on a cobalt-based high-temperature alloy substrate (GH5188), each single layer is 30 μm thick, the printing pitch is 100 μm, and each layer is rotated 67°.

[0047] Figure 2 : is the microhardness distribution diagram of the product obtained in this example. It can be seen that the microhardness of the obtained product increases when the microhardness transitions from the GRCop-42 copper-based high-temperature alloy layer to the GH5188 cobalt-based high-temperature alloy layer.

[0048] Figure 3 This is the heterogeneous grain morphology of the copper-based high-temperature alloy / cobalt-based high-temperature alloy heterogeneous composite material prepared in this embodiment. It can be seen that the heterogeneous structure is divided into three layers, namely the CuCrNb region, the GH5188 / CuCrNb interface region and the GH5188 region, which illustrates the gradient transition of the grain morphology.

[0049] The engineering stress-strain curve of the product obtained in this example is shown in Figure 4 The results showed that the tensile strength of the product was 519 MPa, the yield strength was 328 MPa, and the elongation was 18.6%.

[0050] Example 2

[0051] The difference between this embodiment and embodiment 1 is that the laser power in step 3) is adjusted to 290 W, and the rest of the preparation process is the same as that in embodiment 1, to obtain a copper-based high-temperature alloy / cobalt-based high-temperature alloy heterogeneous composite material.

[0052] The engineering stress-strain curve of the product obtained in this example is shown in Figure 4 The results showed that the tensile strength of the product was 482MPa, the yield strength was 341MPa, and the elongation was 3.4%.

[0053] Example 3

[0054] The difference between this embodiment and embodiment 1 is that the laser power in step 3) is adjusted to 350 W, and the rest of the preparation process is the same as that in embodiment 1, to obtain a copper-based high-temperature alloy / cobalt-based high-temperature alloy heterogeneous composite material.

[0055] The engineering stress-strain curve of the product obtained in this example is shown in Figure 4 The results showed that the tensile strength of the product was 480MPa, the yield strength was 307MPa, and the elongation was 3.9%.

[0056] Example 4

[0057] The difference between this embodiment and embodiment 1 is that the scanning power of step 3) is adjusted to 900 mm / s, and the rest of the preparation process is the same as that of embodiment 1, and a copper-based high-temperature alloy / cobalt-based high-temperature alloy heterogeneous composite material is obtained.

[0058] The engineering stress-strain curve of the product obtained in this example is shown in Figure 4 The results showed that the tensile strength of the product was 466MPa, the yield strength was 318MPa, and the elongation was 2.8%.

[0059] Example 5

[0060] The difference between this embodiment and embodiment 1 is that the scanning power of step 3) is adjusted to 1400 mm / s, and the rest of the preparation process is the same as that of embodiment 1, and a copper-based high-temperature alloy / cobalt-based high-temperature alloy heterogeneous composite material is obtained.

[0061] The engineering stress-strain curve of the product obtained in this example is shown in Figure 4 The results showed that the tensile strength of the product was 514MPa, the yield strength was 304MPa, and the elongation was 13.1%.

[0062] Comparative Example 1

[0063] The difference between this comparative example and Example 1 is that the scanning rate of step 3) is adjusted to 650 mm / s, and the rest of the preparation process is the same as that of Example 1, to obtain a copper-based high-temperature alloy / cobalt-based high-temperature alloy heterogeneous composite material.

[0064] After testing, the tensile strength of the product obtained in this comparative example is 402 MPa, the yield strength is 324 MPa, and the elongation is 1.6%. Compared with Example 1, the tensile strength and yield strength are reduced by 117 MPa and 4 MPa respectively, and the elongation is reduced by 17%.

[0065] The performance of the materials prepared in the above embodiments and comparative examples was tested, and the comparison results with those in Example 1 are shown in Table 1.

[0066] Table 1

[0067] Tensile strength(MPa) Yield strength (MPa) Elongation(%) Example 1 519 328 18.6 Example 2 482 341 3.4 Example 3 480 307 3.9 Example 4 466 318 2.8 Example 5 514 304 13.1 Comparative Example 1 402 324 1.6

[0068] It can be seen from the above table that the adjustment of the laser power and scanning power of the first 20 layers of cobalt-based superalloy layers at the interface has a significant effect on the performance of the copper-based superalloy / cobalt-based superalloy heterogeneous composite material. This is because the volume laser energy density will change when the laser density and scanning rate are adjusted. When the laser energy density is large, the presence of thermal capillary force and recoil pressure inside the molten pool will lead to the existence of keyholes. When the laser energy density is low, the powder is not completely melted, which will form a molten hole mainly composed of unmelted powder particles, accompanied by a small amount of pores; as the scanning rate increases, the cracks at the interface are significantly reduced. When the laser power is 320W and the scanning rate is 1150mm / s, the cracks in each group of samples are significantly reduced, and equiaxed crystals are formed, which further inhibits the formation of cracks. In this process, the uniform distribution of CuCrNb and GH5188 is achieved, and a deeper molten pool is obtained, which provides more space for the flow of metal liquid and forms a wider transition layer, thereby further improving the interface bonding strength. According to the results in the above table, the best technical effect can be obtained when the laser power of the first 20 layers of cobalt-based high-temperature alloy at the interface in the present invention is 320W and the scanning power is 1150mm / s.

[0069] Example 6

[0070] The difference between this embodiment and embodiment 1 is that X is adjusted to 10, and the rest of the preparation process is the same as that of embodiment 1, to prepare a copper-based high-temperature alloy / cobalt-based high-temperature alloy heterogeneous composite material.

[0071] Example 7

[0072] The difference between this embodiment and embodiment 1 is that X is adjusted to 30, and the rest of the preparation process is the same as that of embodiment 1, to prepare a copper-based high-temperature alloy / cobalt-based high-temperature alloy heterogeneous composite material.

[0073] The mechanical properties of the materials prepared in the above embodiment were tested, and the results compared with those in Example 1 are shown in Table 2.

[0074] Table 2

[0075]

[0076]

[0077] It can be seen from the above table that adjusting the number of layers at the junction of the two metals has a significant effect on the performance of the copper-based high-temperature alloy / cobalt-based high-temperature alloy heterogeneous composite materials. This is because the cobalt-based high-temperature alloy layer at the interface serves as a transition layer. When X=10, the transition layer is too thin to achieve a complete gradient transformation of the grain structure, affecting the elongation of the material; when X=30, the transition layer is too thick, which increases the content of cobalt alloy printed by the non-optimal process at the interface, which in turn affects the overall mechanical properties; when X=20, the grain structure and material component gradient transformation of the copper alloy to the cobalt alloy can be effectively achieved, thereby obtaining the optimal performance.

[0078] Comparative Example 2

[0079] This comparative example provides a preparation method of 316L / CuSn10 bimetal, specifically:

[0080] 1) A 316L stainless steel substrate with a size of 125 mm × 125 mm × 40 mm and a surface sandblasted surface was selected as the substrate, and the surface oil stains were cleaned with anhydrous ethanol.

[0081] 2) The building cabin was filled with high-purity argon (<200ppm) to prevent oxidation of the sample during the printing process; 316L powder with an average particle size of 10-80μ was weighed and put into the powder tank; the laser power of the laser powder bed melting equipment was adjusted to 320W, the scanning rate was 650mm / s, the layer thickness was 50μm, the scanning spacing was 120μm, and each layer was rotated 67°. The high-power continuous wave laser beam formed a molten pool on the substrate, and the powder was quickly melted and solidified. 540 layers (of the same composition) of 316L stainless steel were deposited on the 316L stainless steel substrate, and then 10 layers (of the same composition) of 316L stainless steel were deposited by x scanning (unidirectional scanning along one axis). The other preparation processes were the same.

[0082] 3) Put CuSn10 powder with an average particle size of 10 to 80 μm into the powder tank, re-spread the powder, preheat the substrate, set the laser power to 400W, the scanning power to 500mm / s, the layer thickness to 50μm, and the scanning interval to 100μm, and deposit 10 layers of CuSn10 alloy layers (same composition) at the interface by x scanning (scanning in one direction along one axis), and then rotate each layer by 67°. The other preparation processes are the same, and continue to deposit 540 layers of CuSn10 alloy layers (same composition). The printing of 316L / CuSn10 bimetal is completed.

[0083] The tensile strength of the product obtained in Comparative Example 2 was 450 MPa, the yield strength was 315 MPa, and the elongation was 16.6%.

[0084] Comparative Example 3

[0085] This comparative example provides a preparation method of Inconel 718 / GRCop84 bimetal, specifically:

[0086] 1) Select Inconel718 stainless steel substrate as the substrate, first polish the surface of the substrate with sandpaper, and then clean the surface oil stains with anhydrous ethanol.

[0087] 2) The building cabin was filled with high-purity argon (<1000ppm) to prevent oxidation of the sample during printing; Inconel718L stainless steel powder was weighed and put into the powder tank; the laser power of the laser powder bed melting equipment was adjusted to 450W, the scanning rate was 0.5m / min, the layer thickness was 250μm, and the scanning spacing was 530μm. The high-power continuous wave laser beam formed a molten pool on the substrate, the powder melted and solidified rapidly, and 28 layers (of the same composition) of Inconel718 stainless steel alloy were deposited on the Inconel718 stainless steel substrate.

[0088] 3) Put GRCop-84 copper-based high-temperature alloy powder into the powder tank, re-spread the powder, preheat the substrate, set the laser power to 450W, the scanning power to 0.4m / min, the layer thickness to 530μm, the scanning interval to 530μm, and deposit 50 layers of GRCop-84 copper-based high-temperature alloy layers. Complete the printing of Inconel 718 / GRCop84 bimetal.

[0089] The tensile strength of the product obtained in Comparative Example 3 is 478 MPa, the yield strength is 220 MPa, and the elongation is 6.8%.

[0090] Comparative Example 4

[0091] The difference between this comparative example and Example 1 is that the layer thickness is adjusted to 100 μm, and the rest of the preparation process is the same as that of Example 1, to obtain a copper-based high-temperature alloy / cobalt-based high-temperature alloy heterogeneous composite material.

[0092] The mechanical properties of the material obtained in the above comparative example were tested, and the comparison results with those of Example 1 are shown in Table 3.

[0093] Table 3

[0094] Tensile strength(MPa) Yield strength (MPa) Elongation(%) Example 1 519 328 18.6 Comparative Example 2 450 315 16.6 Comparative Example 3 478 220 6.8 Comparative Example 4 245 239 2.1

[0095] It can be seen from the above table that the copper-based high-temperature alloy / cobalt-based high-temperature alloy heterogeneous composite material prepared by the present invention suppresses the segregation of carbon elements at the interface by effectively regulating the process parameters, thereby reducing the generation of cracks at the interface, and obtains a copper-based high-temperature alloy / cobalt-based high-temperature alloy heterogeneous composite material with excellent properties (including tensile strength, yield strength, elongation, etc.).

[0096] Adjusting the layer thickness has a significant effect on the performance of copper-based high-temperature alloy / cobalt-based high-temperature alloy heterogeneous composite materials. This is because in the L-PBF printing of the Co-Cu material system, the Marangoni convection-induced circulating flow in the molten pool is the main driving force for the migration of dissimilar elements. The size of the molten pool, especially the depth of the molten pool, directly affects the migration of elements, thereby affecting the bonding strength of dissimilar materials. The results show that the optimal laser energy density can only penetrate and melt a thin layer of Co alloy powder, in which Co reacts with Cu brought by the circulating flow of the molten pool. The thick Co-Cu reaction zone will cause the Co alloy powder to not be completely melted, forming melting holes mainly composed of unmelted powder particles, accompanied by a large number of pores. Therefore, the best technical effect can be obtained when the layer thickness in the present invention is 30μm.

[0097] In summary, the present invention uses copper-based high-temperature alloy powder and cobalt-based high-temperature alloy powder as raw materials, and prepares copper-based high-temperature alloy / cobalt-based high-temperature alloy heterogeneous composite materials through laser powder bed melting technology. Compared with traditional preparation processes such as stir friction welding and hot rolling, it can realize moldless manufacturing and direct manufacturing of large and small complex parts; especially for the molding of the interface connection of heterogeneous composite materials, it can realize precise control of composition and structure, and the production cycle involved is short, the utilization rate of raw materials is improved, and it is suitable for popularization and application.

[0098] The copper-based high-temperature alloy / cobalt-based high-temperature alloy heterogeneous composite material prepared by the present invention preferably uses a cobalt alloy that exhibits better stress fracture performance under long time and high temperature.

[0099] The copper-based high-temperature alloy / cobalt-based high-temperature alloy heterogeneous composite material prepared by the present invention, when printing the first X layers of cobalt-based high-temperature alloy layers (10≤X≤30) at the interface, suppresses the segregation of carbon elements at the interface by effectively regulating process parameters, thereby reducing the generation of cracks at the interface, thereby achieving macro-defect-free additive manufacturing of copper-based and cobalt-based alloy composite materials with large physical property differences.

[0100] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A method for preparing a copper-based high-temperature alloy / cobalt-based high-temperature alloy heterogeneous composite material, characterized in that: include, Laser powder bed melting technology is used to spread powder and preheat the substrate. In a protective atmosphere, copper-based high-temperature alloy spherical powder is used as raw material to print a copper-based high-temperature alloy layer on the surface of the substrate. Then, the powder is replaced, the powder is re-spread, and the powder is preheated. In a protective atmosphere, the cobalt-based superalloy spherical powder is used as a raw material to print the cobalt-based superalloy layer A at the interface of the copper-based superalloy / cobalt-based superalloy; Then, a cobalt-based high-temperature alloy layer B is printed; that is, a copper-based high-temperature alloy / cobalt-based high-temperature alloy heterogeneous composite material is obtained; The number of the copper-based high-temperature alloy layers is equal to the number of the cobalt-based high-temperature alloy layers, and the number of the cobalt-based high-temperature alloy layers A is 10 to 30.

2. The method for preparing the copper-based high-temperature alloy / cobalt-based high-temperature alloy heterogeneous composite material according to claim 1, characterized in that: The copper-based high-temperature alloy includes one or more of GRCop-42 and GRCop-84.

3. The method for preparing the copper-based high-temperature alloy / cobalt-based high-temperature alloy heterogeneous composite material according to claim 1, characterized in that: The cobalt-based high-temperature alloy includes one or more of GH5188 and GH5606.

4. The method for preparing the copper-based high-temperature alloy / cobalt-based high-temperature alloy heterogeneous composite material according to claim 1, characterized in that: The copper-based high-temperature alloy powder and the cobalt-based high-temperature alloy powder are both micron-sized spherical powders.

5. The method for preparing the copper-based high-temperature alloy / cobalt-based high-temperature alloy heterogeneous composite material according to claim 1, characterized in that: The protective atmosphere includes one or more of argon and nitrogen.

6. The method for preparing the copper-based high-temperature alloy / cobalt-based high-temperature alloy heterogeneous composite material according to claim 1, characterized in that: The process parameters of the laser powder bed melting used for the copper-based high-temperature alloy layer are: laser power of 340-370 W, scanning rate of 650-900 mm / s, printing spacing of 100 μm, layer thickness of 30 μm, and rotation of each layer of 67°.

7. The method for preparing the copper-based high-temperature alloy / cobalt-based high-temperature alloy heterogeneous composite material according to claim 1, characterized in that: The process parameters of the laser powder bed melting used for the cobalt-based high-temperature alloy layer A are: laser power of 290-350 W, scanning rate of 900-1400 mm / s, printing spacing of 100 μm, layer thickness of 30 μm, and rotation of each layer by 67°.

8. The method for preparing the copper-based high-temperature alloy / cobalt-based high-temperature alloy heterogeneous composite material according to claim 1, characterized in that: The process parameters of the laser powder bed melting used for the cobalt-based high-temperature alloy layer B are: laser power of 230-260 W, scanning rate of 650-900 mm / s, printing spacing of 100 μm, layer thickness of 30 μm, and rotation of each layer by 67°.

9. The method for preparing the copper-based high-temperature alloy / cobalt-based high-temperature alloy heterogeneous composite material according to claim 1, characterized in that: The substrate includes a cobalt-based high-temperature alloy.

10. A copper-based high-temperature alloy / cobalt-based high-temperature alloy heterogeneous composite material prepared by the preparation method according to any one of claims 1 to 9, characterized in that: Starting from the substrate, it includes, Copper-based high-temperature alloy layer; Cobalt-based superalloy layer A at the copper-based superalloy / cobalt-based superalloy interface; Cobalt-based high-temperature alloy layer B; The number of the copper-based high-temperature alloy layers is equal to the number of the cobalt-based high-temperature alloy layers, and the number of the cobalt-based high-temperature alloy layers A is 10 to 30.

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