CoCrNi medium-entropy alloy-based composite material and additive manufacturing method and application thereof

Abstract

The invention discloses a CoCrNi medium-entropy alloy-based composite material and an additive manufacturing method and application thereof, and belongs to the technical field of materials. The CoCrNi medium-entropy alloy-based composite material is obtained by carrying out additive manufacturing on composite powder formed by CoCrNi medium-entropy alloy powder and WC powder in a laser powder bed melting forming mode. The CoCrNi medium-entropy alloy-based composite material comprises a matrix with an FCC structure, and WC particles and submicron carbide M23C6 are distributed in the matrix; wherein the WC particles are in a partial molten state, and an element transition layer is arranged between the WC particles and the matrix. The medium-entropy alloy-based composite material has the characteristics of high strength, high toughness, excellent wear resistance, low cost and the like, can effectively solve the problems of lower strength and poorer wear resistance of CoCrNi medium-entropy alloy, and can be applied to aerospace lightweight bearing parts, high-performance wear-resistant parts, high-end tool molds and the like.

Description

Technical Field

[0001] This invention relates to the field of materials technology, and more specifically, to a CoCrNi medium-entropy alloy-based composite material and its additive manufacturing method and application. Background Technology

[0002] Additive manufacturing, especially laser powder bed melting (LPBF) technology, provides a revolutionary approach to manufacturing high-performance metal components with complex geometries. Among many advanced metallic materials, medium-entropy alloys such as CoCrNi have broad application prospects in aerospace, biomedicine, and energy and chemical industries due to their unique compositional design concepts. However, CoCrNi medium-entropy alloys prepared by traditional LPBF processes still face some performance bottlenecks. For example, their room temperature strength is still insufficient compared to some traditional high-strength alloys, limiting their application in extremely heavy-duty components; their inherent hardness and wear resistance are also poor, limiting their service life under conditions involving friction and wear.

[0003] In view of this, the present invention is proposed. Summary of the Invention

[0004] The purpose of this invention is to provide a CoCrNi medium-entropy alloy-based composite material and its additive manufacturing method and application, so as to solve or improve the above-mentioned technical problems.

[0005] This invention can be implemented as follows: In a first aspect, the present invention provides a CoCrNi medium-entropy alloy-based composite material, which is obtained by additive manufacturing of a composite powder formed by CoCrNi medium-entropy alloy powder and WC powder through laser powder bed melting forming. CoCrNi medium-entropy alloy matrix composites include a matrix with an FCC structure, in which WC particles and submicron carbides M are distributed. 23 C6; wherein the WC particles are in a partially molten state, and there is an elemental transition layer between the WC particles and the matrix.

[0006] In an optional embodiment, the composite powder has at least one of the following characteristics: Feature 1: The mass ratio of CoCrNi medium-entropy alloy powder to WC powder is 93:7 to 99:1; preferably, the mass ratio of CoCrNi medium-entropy alloy powder to WC powder is 95:5; Feature 2: The particle size of the CoCrNi medium-entropy alloy powder is 15μm~53μm; Feature 3: The particle size of WC powder is 15μm~53μm; Feature 4: The sphericity of WC powder is not less than 95%.

[0007] In an optional implementation, the width of the element transition layer is 5 μm to 10 μm.

[0008] In an optional implementation, submicron carbide M 23 The size of C6 is 100nm~400nm.

[0009] In an optional embodiment, the CoCrNi medium-entropy alloy-based composite material also has at least one of the following characteristics: Feature 5: The tensile strength of CoCrNi medium-entropy alloy matrix composites is 880MPa~1215MPa; Feature 6: The yield strength of CoCrNi medium-entropy alloy-based composite materials is 537MPa~897MPa; Feature 7: The elongation after fracture of CoCrNi medium-entropy alloy-based composite materials is 11.2%~53.5%; Feature 8: The impact toughness of the CoCrNi medium-entropy alloy matrix composite is 32.1 J / cm. 2 ~141.2 J / cm 2 ; Feature 9: The hardness of the CoCrNi medium-entropy alloy matrix composite material is 24.9 HRC~36.7 HRC; Feature 10: The volumetric wear rate of the CoCrNi medium-entropy alloy-based composite material is 2.1%. 10 -4 mm 3 / (N·m)~7.5 10 -4 mm 3 / (N·m).

[0010] In a second aspect, the present invention provides an additive manufacturing method for a CoCrNi medium-entropy alloy-based composite material as described in any of the foregoing embodiments, comprising the following steps: additive manufacturing of a composite powder formed by CoCrNi medium-entropy alloy powder and WC powder by laser powder bed melting.

[0011] In an optional embodiment, the composite powder is obtained by mechanically mixing CoCrNi medium-entropy alloy powder and WC powder at 10 rpm to 30 rpm for 4 h to 10 h.

[0012] In an optional embodiment, the composite powder is dried before being subjected to laser powder bed melting.

[0013] In an optional embodiment, the conditions for laser powder bed melting and forming include: laser power of 150W~350W, scanning speed of 500mm / s~1500mm / s, scanning spacing of 0.06mm~0.12mm, powder layer thickness of 0.03mm~0.08mm, and scanning strategy of strip scanning or partition scanning with layer-by-layer rotation.

[0014] In an optional embodiment, the volume energy density of laser powder bed melting is 60 J / mm². 3 ~80J / mm 3 .

[0015] In an optional embodiment, laser powder bed melting is performed under a protective atmosphere.

[0016] In an optional implementation, the material obtained from additive manufacturing is subjected to heat treatment.

[0017] In an optional embodiment, the heat treatment includes annealing at 1000℃~1100℃ for 1h~3h followed by water quenching or oil quenching.

[0018] In an optional embodiment, the heat treatment includes annealing at 1100°C for 2 hours followed by water quenching.

[0019] Thirdly, the present invention provides an application of the CoCrNi medium-entropy alloy-based composite material as described in any of the foregoing embodiments. For example, the CoCrNi medium-entropy alloy-based composite material can be used to prepare lightweight load-bearing components for aerospace, high-performance wear-resistant parts, and / or high-end tool molds, etc.

[0020] The beneficial effects of this invention include: The CoCrNi medium-entropy alloy matrix composite material provided by this invention is obtained by additive manufacturing of a composite powder formed from CoCrNi medium-entropy alloy powder and WC powder through laser powder bed melting. The CoCrNi medium-entropy alloy matrix composite material includes a matrix with an FCC structure, in which WC particles and submicron carbides M are distributed. 23 C6; wherein the WC particles are in a partially molten state, and there is an elemental transition layer between the WC particles and the matrix. This medium-entropy alloy matrix composite material has the characteristics of high strength, high toughness, excellent wear resistance and low cost, which can effectively solve the problems of low strength and poor wear resistance of CoCrNi medium-entropy alloys, and can be applied to lightweight load-bearing components in aerospace, high-performance wear-resistant parts, high-end tool molds, etc. Attached Figure Description

[0021] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 These are scanning electron microscope images of the CoCrNi medium-entropy alloy powder used in the embodiments and comparative examples of this invention. Figure 2 These are scanning electron microscope images of the WC powder used in the embodiments and comparative examples of the present invention; Figure 3 The X-ray diffraction patterns are those of the CoCrNi medium-entropy alloy-based composite material prepared in Example 3 of the present invention and the medium-entropy alloy material prepared in Comparative Example 1. Figure 4 This is a scanning electron microscope image of a large area of ​​the microstructure of the CoCrNi medium-entropy alloy-based composite material prepared in Example 3 of the present invention; Figure 5 This is a scanning electron microscope image of partially molten WC particles and their surroundings in the microstructure of the CoCrNi medium-entropy alloy matrix composite material prepared in Example 3 of the present invention. Figure 6 The line scan curves from the center of partially molten WC particles to the matrix in the microstructure of the CoCrNi medium-entropy alloy matrix composite material prepared in Example 3 of this invention are shown. Figure 7 This is a scanning electron microscope image of carbides precipitated in the CoCrNi medium-entropy alloy matrix obtained in Example 3 of the present invention. Figure 8 The room temperature tensile stress-strain curves of the CoCrNi medium-entropy alloy matrix composite material prepared in Example 3 of the present invention and the medium-entropy alloy material prepared in Comparative Example 1 are shown. Figure 9 This is a scanning electron microscope image of the room temperature tensile fracture surface of the CoCrNi medium-entropy alloy matrix composite material prepared in Example 3 of the present invention. Figure 10 This is a scanning electron microscope image of the room temperature impact fracture surface of the CoCrNi medium-entropy alloy matrix composite material prepared in Example 3 of the present invention. Figure 11 The two-dimensional contour curves of the wear pits after room temperature friction and wear are shown for the CoCrNi medium-entropy alloy matrix composite material prepared in Example 3 of the present invention and the medium-entropy alloy material prepared in Comparative Example 1. Figure 12This is a scanning electron microscope image of the overall room temperature tribological surface of the CoCrNi medium-entropy alloy-based composite material prepared in Example 3 of the present invention. Figure 13 This is a scanning electron microscope image of local wear pits on the room temperature friction and wear surface of the CoCrNi medium-entropy alloy-based composite material prepared in Example 3 of the present invention; Figure 14 This is a scanning electron microscope image of the microstructure of the medium-entropy alloy material prepared in Comparative Example 1 of this invention. Figure 15 This is a scanning electron microscope image of the room temperature tensile fracture surface of the medium-entropy alloy material prepared in Comparative Example 1 of the present invention. Figure 16 This is a scanning electron microscope image of the room temperature impact fracture surface of the medium-entropy alloy material prepared in Comparative Example 1 of the present invention. Figure 17 This is a scanning electron microscope image of the overall room temperature tribological wear surface of the medium-entropy alloy material prepared in Comparative Example 1 of the present invention. Figure 18 This is a scanning electron microscope image of local wear pits on the room temperature friction and wear surface of the medium-entropy alloy material prepared in Comparative Example 1 of this invention. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall apply. Reagents or instruments whose manufacturers are not specified are all conventional products that can be purchased commercially.

[0024] The CoCrNi medium-entropy alloy-based composite material, its preparation method, and its application provided by this invention will be described in detail below.

[0025] This invention provides a CoCrNi medium-entropy alloy-based composite material, which is obtained by additive manufacturing of a composite powder formed by CoCrNi medium-entropy alloy powder and WC powder through laser powder bed melting.

[0026] The aforementioned CoCrNi medium-entropy alloy-based composite material includes a matrix with an FCC structure, in which WC particles and submicron carbides M are distributed. 23 C6; wherein the WC particles are in a partially molten state, and there is an elemental transition layer between the WC particles and the matrix.

[0027] By introducing spherical hard WC particles as a reinforcing phase and combining them with specific LPBF process conditions, effective grain refinement and second-phase reinforcement of the CoCrNi matrix are achieved. This CoCrNi medium-entropy alloy-based composite material, while maintaining the inherent good toughness of medium-entropy alloys, exhibits significantly improved room-temperature strength, hardness, and wear resistance, overcoming the shortcomings of insufficient strength and wear resistance in single medium-entropy alloys. Furthermore, the submicron carbides M2 present in the CoCrNi medium-entropy alloy-based composite material... 23 C6 effectively hinders dislocation movement, significantly improving material strength while maintaining good toughness. The elemental transition layer can share the load borne by the matrix, achieving overall reinforcement of the composite material.

[0028] In some optional embodiments, the mass ratio of CoCrNi medium-entropy alloy powder to WC powder can be from 93:7 to 99:1, such as 93:7, 94:6, 95:5, 96:4, 97:3, 98:2, or 99:1, or other values ​​within the range of 93:7 to 99:1. In some preferred embodiments, the mass ratio of CoCrNi medium-entropy alloy powder to WC powder is 95:5.

[0029] The above conditions enable WC particles to achieve performance gains even at low addition levels, which is beneficial for improving the utilization efficiency of reinforcing particles. Furthermore, compared to traditional methods that rely on large amounts of expensive alloying elements for strengthening, this invention effectively reduces raw material costs while achieving equal or even better performance levels.

[0030] In some optional embodiments, the CoCrNi medium-entropy alloy powder is a spherical powder with a particle size of 15 μm to 53 μm. Preferably, spherical CoCrNi medium-entropy alloy powder prepared by gas atomization can be used to ensure good flowability and powder spreading effect.

[0031] In some optional embodiments, the WC powder is spherical powder with a particle size of 15μm to 53μm and a sphericity of not less than 95%. Preferably, high-purity WC powder with a sphericity (which can be 95%, 96%, 97%, 98%, or 99%, or other values ​​within the range of 95% to 99%) prepared by an radio frequency plasma powder preparation system can be selected. The spherical morphology is beneficial for uniform dispersion during mixing and reduces the angular effect during laser scanning, thereby inhibiting crack initiation.

[0032] In some optional embodiments, the width of the elemental transition layer is 5 μm to 10 μm (e.g., 5 μm, 6 μm, 7 μm, 8 μm, 9 μm, or 10 μm). If the width of the elemental transition layer is too small, it is not conducive to the precipitation of sufficient carbide M. 23 C6.

[0033] In some alternative implementations, submicron carbides M 23 The scale of C6 is 100nm~400nm, such as 100nm, 200nm, 300nm or 400nm, or other values ​​in the range of 100nm~400nm.

[0034] If carbide M 23 The size of C6 is greater than 400nm, which is not conducive to improving strength and ensuring toughness.

[0035] In some alternative embodiments, the tensile strength of the CoCrNi medium-entropy alloy matrix composite is 880 MPa to 1215 MPa.

[0036] In some alternative embodiments, the yield strength of the CoCrNi medium-entropy alloy matrix composite is 537 MPa to 897 MPa.

[0037] In some alternative embodiments, the elongation after fracture of the CoCrNi medium-entropy alloy matrix composite is 11.2% to 53.5%.

[0038] In some alternative embodiments, the impact toughness of the CoCrNi medium-entropy alloy matrix composite is 32.1 J / cm. 2 ~141.2 J / cm 2 .

[0039] In some alternative embodiments, the hardness of the CoCrNi medium-entropy alloy matrix composite material is 24.9 HRC to 36.7 HRC.

[0040] In some alternative embodiments, the volumetric wear rate of the CoCrNi medium-entropy alloy matrix composite is 2.1. 10 - 4 mm 3 / (N·m)~7.5 10 -4 mm 3 / (N·m).

[0041] Building upon the above, the medium-entropy alloy-based composite material provided by this invention possesses advantages such as high strength, high toughness, excellent wear resistance, and low cost, which can be reflected in the following aspects: (1) Grain refinement: The optimized LPBF process parameters can achieve a higher cooling rate and a smaller melt pool size, effectively suppressing grain growth. At the same time, spherical WC particles can act as heterogeneous nucleation sites during solidification, further refining the matrix grains. The fine-grained structure not only improves the strength of the material, but also maintains good toughness.

[0042] (2) Second-phase strengthening (dispersion strengthening / precipitation strengthening): Spherical WC particles partially dissolve under laser irradiation, releasing W and C elements that are dissolved in the CoCrNi matrix. During subsequent rapid solidification and heat treatment, these supersaturated dissolved elements are released as carbides at the submicron scale (100nm~400nm). 23 C6 is dispersed and precipitated within the matrix. These nanoprecipitates effectively hinder dislocation movement, significantly improving the material's strength, while the supersaturated solid solution formed by rapid cooling also helps maintain good toughness.

[0043] (3) Load transfer strengthening: There is a good interfacial metallurgical bond between the spherical WC particles and the CoCrNi matrix, and there is a distinct elemental transition layer with a width of 5μm~10μm. When the material is subjected to an external load, the strength and hardness of this elemental transition layer are much higher than those of the WC particles in the matrix, which can effectively bear and transfer stress, thereby sharing the load borne by the matrix and achieving overall strengthening of the composite material.

[0044] (4) Synergistic effect of solid solution strengthening: Partially dissolved W and C atoms are dissolved in the CoCrNi matrix with FCC structure, causing lattice distortion, increasing the resistance to dislocation movement, and providing additional solid solution strengthening effect.

[0045] (5) Hard phase support and anti-ploughing effect: The spherical WC particles uniformly distributed in the matrix have extremely high hardness. During the friction process, they can act as the main bearing phase, effectively resisting the micro-ploughing and micro-cutting action on the grinding parts, protecting the relatively soft metal matrix, and thus greatly reducing the wear rate.

[0046] (6) Synergistic effect of matrix toughness and particle anchoring: The good toughness of the CoCrNi matrix ensures that WC particles are firmly anchored in the matrix and are not easy to peel off even under cyclic load. The strong interfacial bonding can avoid the early detachment of the reinforcing phase during the wear process, so that WC particles can play a continuous and stable anti-wear role.

[0047] (7) Adaptive surface and wear debris control: In the early stage of wear, the softer matrix will undergo slight wear, making the protruding WC particles more visible and forming an ideal wear-resistant surface morphology with hard particles as support points. At the same time, the detached WC fragments may be further refined during the friction process and mixed with the matrix material. Under certain conditions, this can help form a transfer film or third body layer with lubricating or hardening effects, thereby improving the friction state and reducing wear.

[0048] (8) Refining the structure enhances the resistance to plastic deformation: The refined grains and dispersed nano-precipitates significantly improve the hardness and yield strength of the matrix itself, enhance the material surface's ability to resist plastic deformation and fatigue spalling, thereby improving the overall wear resistance.

[0049] Accordingly, the present invention also provides an additive manufacturing method for the above-mentioned CoCrNi medium-entropy alloy-based composite material, which may include the following steps: additive manufacturing of a composite powder formed by CoCrNi medium-entropy alloy powder and WC powder by laser powder bed melting.

[0050] It is important to emphasize that LPBF composites of hard WC particles with metal matrices typically present numerous challenges. For example, violent interfacial reactions can occur between WC particles and the molten metal, generating brittle phases and severely deteriorating the toughness of the composite material. Furthermore, traditional irregular or angular WC particles are prone to segregation, burn-off, or decomposition within the laser molten pool, leading to uneven distribution of the reinforcing phase, uncontrolled composition, and potentially microcracks, resulting in unstable or even diminished performance enhancements. Additionally, existing LPBF process parameters are mostly optimized for single alloy powders; when directly applied to composite material preparation, the molten pool kinetics change drastically, easily generating defects such as porosity and incomplete fusion. These combined issues mean that WC particle-reinforced metal matrix composites prepared via LPBF often fail to simultaneously possess high strength, high toughness, and excellent wear resistance.

[0051] Based on this, through long-term exploration and research on the preparation process and conditions, this invention has creatively proposed a scheme that can effectively prepare CoCrNi medium-entropy alloy-based composite materials with high strength, high toughness and excellent wear resistance, including the preparation of composite powder, the conditions for laser powder bed melting and forming, and the heat treatment process.

[0052] In some optional embodiments, the composite powder can be obtained by mechanically mixing CoCrNi medium-entropy alloy powder and WC powder at 10 rpm to 30 rpm (e.g., 10 rpm, 20 rpm, or 30 rpm) for 4 h to 10 h (e.g., 4 h, 5 h, 6 h, 7 h, 8 h, 9 h, or 10 h). The above mixing process can be carried out in a double cone high-efficiency mixer.

[0053] By performing low-speed, long-term mechanical mixing, WC particles can be uniformly dispersed around CoCrNi powder, forming a composite powder with uniform composition.

[0054] In some alternative implementations, the composite powder is dried before laser powder bed melting to remove moisture from the composite powder and avoid affecting the laser powder bed melting effect.

[0055] In some alternative implementations, the uniformly mixed composite powder can be loaded into the powder supply system of a metal laser powder bed melting equipment, a high-purity argon protective atmosphere can be established in the forming cavity, and then laser powder bed melting can be performed under specific conditions.

[0056] The conditions for laser powder bed melting and forming may include: laser power of 150W~350W, scanning speed of 500mm / s~1500mm / s, scanning spacing of 0.06mm~0.12mm, powder layer thickness of 0.03mm~0.08mm, and scanning strategy of strip scanning or partition scanning with layer-by-layer rotation.

[0057] The aforementioned laser powder bed melting conditions can effectively suppress harmful brittle interfacial reactions between reinforcing particles and the molten matrix, promoting the formation of a firmly bonded diffusion-type interface. Furthermore, they ensure a uniform and stable distribution of reinforcing particles within the matrix, eliminating microscopic defects and stress concentrations caused by particle segregation or irregular morphology, thus enabling the composite material to possess both high strength and high toughness.

[0058] The laser power can be 150W, 180W, 200W, 220W, 250W, 280W, 300W, 320W or 350W, or other values ​​within the range of 150W to 350W.

[0059] The scanning speed can be 500mm / s, 800mm / s, 1000mm / s, 1200mm / s or 1500mm / s, or other values ​​within the range of 500mm / s to 1500mm / s.

[0060] The scanning interval can be 0.06mm, 0.07mm, 0.08mm, 0.09mm, 0.10mm, 0.11mm or 0.12mm, or other values ​​within the range of 0.06mm to 0.12mm.

[0061] The thickness of the powder layer can be 0.03mm, 0.04mm, 0.05mm, 0.06mm, 0.07mm or 0.08mm, or other values ​​within the range of 0.03mm to 0.08mm.

[0062] In some alternative implementations, the volume energy density of laser powder bed melting can be 60 J / mm². 3 ~80J / mm 3 For example, 60J / mm 3 65J / mm 3 70J / mm 3 75J / mm 3 Or 80J / mm 3 etc., or 60J / mm 3 ~80J / mm 3 Other values ​​within the range.

[0063] In some alternative implementations, the rotation angle layer by layer may, for example, be 67°.

[0064] By employing the aforementioned moderate laser power combined with a relatively high scanning speed, a molten pool of moderate size and short duration is formed. This ensures that the matrix alloy is fully melted and forms a good metallurgical bond with the WC particles, while minimizing the excessive dissolution and decomposition of the WC particles and avoiding the formation of harmful brittle phases (such as the η phase). Laser power less than 150W is unfavorable for preparing highly dense composite materials; laser power greater than 350W is unfavorable for forming a diffusion-type interface with good metallurgical bonding. Scanning speed less than 500mm / s is unfavorable for forming a stable molten pool and preparing highly dense composite materials; scanning speed greater than 1500mm / s is unfavorable for preparing highly dense composite materials.

[0065] Interlayer scanning rotation can reduce heat accumulation, promote uniform heat distribution, and obtain a more isotropic microstructure. Simultaneously, using partitioned or strip scanning can avoid overheating and WC particle agglomeration caused by large-area continuous scanning.

[0066] By controlling the scanning spacing to 0.06mm~0.12mm and the powder layer thickness to 0.03mm~0.08mm, the volume energy density can be controlled at 60J / mm². 3 ~80J / mm 3 This ensures that the composite material possesses advantages such as a density ≥99.5%, low defects, and good interfacial bonding. A scanning interval less than 0.06 mm is detrimental to forming good overlap between adjacent melt channels; a scanning interval greater than 0.12 mm is detrimental to preparing a highly dense composite material. Similarly, a powder layer thickness less than 0.03 mm is detrimental to achieving good powder spreading; a powder layer thickness greater than 0.08 mm is detrimental to preparing a highly dense composite material.

[0067] In some optional implementations, the laser power is 300W~350W, the scanning speed is 1000mm / s~1500mm / s, the scanning interval is 0.06mm~0.08mm, and the powder thickness is 0.05mm~0.08mm.

[0068] As described above, the present invention, by following the specific laser powder bed melting and forming conditions, can effectively control the thermal behavior and solidification process of the molten pool, significantly reduce typical additive manufacturing defects such as porosity, cracks, and lack of fusion, and obtain formed parts with high density and low residual stress.

[0069] Furthermore, the material obtained by the above additive manufacturing is subjected to heat treatment to regulate the microstructure of the material and release internal stress.

[0070] Heat treatment may include annealing at 1000℃~1100℃ for 1h~3h followed by water quenching or oil quenching. This process can be carried out in a vacuum or protective atmosphere furnace.

[0071] The annealing temperature can be 1000℃, 1020℃, 1050℃, 1080℃ or 1100℃, or other values ​​within the range of 1000℃ to 1100℃.

[0072] Annealing time can be 1 hour, 1.5 hours, 2 hours, 2.5 hours or 3 hours, or other values ​​within the range of 1 hour to 3 hours.

[0073] In some preferred embodiments, the heat treatment involves annealing at 1100°C for 2 hours followed by water quenching.

[0074] Annealing at 1000℃~1100℃ for 1h~3h allows for further solidification of the non-equilibrium metastable phases (such as partially decomposed WC) formed during additive manufacturing, resulting in a more homogeneous composition. After annealing, rapid water or oil quenching quickly fixes the supersaturated solid solution obtained at high temperatures, providing a good foundation for the material's toughness.

[0075] Continuing from the above, the specific conditions for laser powder bed melting provided by this invention can achieve a higher cooling rate and a smaller melt pool size, effectively suppressing grain growth. Simultaneously, spherical WC particles can act as heterogeneous nucleation sites during solidification, further refining the matrix grains. This fine-grained structure not only improves the material's strength but also maintains good toughness. The spherical WC particles partially dissolve under laser irradiation, releasing W and C elements that are dissolved in the CoCrNi matrix. During subsequent rapid solidification and heat treatment, these supersaturated dissolved elements are released as submicron-scale (100nm~400nm) carbides M... 23 C6 is dispersed and precipitated in the matrix, which can effectively hinder dislocation movement and significantly improve the strength of the material. The supersaturated solid solution formed by rapid cooling is also conducive to maintaining good toughness.

[0076] Furthermore, the present invention also provides an application of the above-mentioned CoCrNi medium-entropy alloy-based composite material. For example, the CoCrNi medium-entropy alloy-based composite material can be used to prepare lightweight load-bearing components for aerospace, high-performance wear-resistant parts and / or high-end tool molds, etc., which greatly expands the application scope and value of medium-entropy alloy materials in additive manufacturing.

[0077] The features and performance of the present invention will be further described in detail below with reference to embodiments.

[0078] The CoCrNi medium-entropy alloy powder and WC powder used in the following examples and comparative examples were all purchased directly. The CoCrNi medium-entropy alloy powder was prepared by gas atomization, with a particle size of 15 μm to 53 μm and a sphericity of 86%. Its scanning electron microscope image is shown below. Figure 1 As shown; WC powder is a powder with a particle size of 15μm~53μm prepared by an radio frequency plasma powder preparation system, with a sphericity of 98%, and its scanning electron microscope image is shown below. Figure 2 As shown.

[0079] Example 1 This embodiment provides a CoCrNi medium-entropy alloy-based composite material, which is obtained by additive manufacturing of a composite powder formed from CoCrNi medium-entropy alloy powder and WC powder through laser powder bed melting. The composite powder comprises 99 wt% CoCrNi medium-entropy alloy powder and 1 wt% WC powder.

[0080] The preparation method of this CoCrNi medium-entropy alloy-based composite material includes: S1: Weigh the CoCrNi medium-entropy alloy and WC powder according to the ratio and put them into a double cone high-efficiency mixer. Mechanically mix them at 10 rpm for 10 h to obtain composite powder.

[0081] S2: The uniformly mixed composite powder is loaded into the powder supply system of the metal laser powder bed melting equipment. A high-purity argon protective atmosphere is established in the forming cavity. Laser powder bed melting is then performed under the following conditions: laser power 150W, scanning speed 500mm / s, scanning interval 0.10mm, powder layer thickness 0.05mm, and scanning strategy of strip scanning with 67° rotation layer by layer. The volume energy density of the laser powder bed melting is 60J / mm². 3 .

[0082] S3: The material obtained by the above additive manufacturing is annealed at 1000℃ for 3 hours and then water quenched.

[0083] Testing revealed that the microstructure of the CoCrNi medium-entropy alloy matrix composite material prepared in this embodiment contained only a small amount of partially molten WC particles and submicron-scale (100nm~400nm) carbides in the FCC structure matrix. 23 C6.

[0084] Example 2 This embodiment provides a CoCrNi medium-entropy alloy-based composite material, which is obtained by additive manufacturing of a composite powder formed from CoCrNi medium-entropy alloy powder and WC powder via laser powder bed melting. The composite powder comprises 97 wt% CoCrNi medium-entropy alloy powder and 3 wt% WC powder.

[0085] The preparation method of this CoCrNi medium-entropy alloy-based composite material includes: S1: Weigh the CoCrNi medium-entropy alloy and WC powder according to the ratio and put them into a double cone high-efficiency mixer. Mechanically mix them at 20 rpm for 8 hours to obtain composite powder.

[0086] S2: The uniformly mixed composite powder is loaded into the powder supply system of the metal laser powder bed melting equipment. A high-purity argon protective atmosphere is established in the forming cavity. Laser powder bed melting is then performed under the following conditions: laser power 250W, scanning speed 500mm / s, scanning interval 0.10mm, powder layer thickness 0.08mm, and scanning strategy of strip scanning with 67° rotation layer by layer. The volume energy density of the laser powder bed melting is 62.5J / mm². 3 .

[0087] S3: Anneal the material obtained by the above additive manufacturing at 1100℃ for 1 hour and then water quench it.

[0088] Testing revealed that the microstructure of the CoCrNi medium-entropy alloy matrix composite material prepared in this embodiment contained a certain amount of partially molten WC particles and submicron-scale (100nm~400nm) carbides in the FCC structure matrix. 23 C6.

[0089] Example 3 This embodiment provides a CoCrNi medium-entropy alloy-based composite material, which is obtained by additive manufacturing of a composite powder formed from CoCrNi medium-entropy alloy powder and WC powder via laser powder bed melting. The composite powder comprises 95 wt% CoCrNi medium-entropy alloy powder and 5 wt% WC powder.

[0090] The preparation method of this CoCrNi medium-entropy alloy-based composite material includes: S1: Weigh the CoCrNi medium-entropy alloy and WC powder according to the ratio and put them into a double cone high-efficiency mixer. Mechanically mix them at 25 rpm for 6 hours to obtain composite powder.

[0091] S2: The uniformly mixed composite powder is loaded into the powder supply system of the metal laser powder bed melting equipment. A high-purity argon protective atmosphere is established in the forming cavity. Laser powder bed melting is then performed under the following conditions: laser power 300W, scanning speed 1000mm / s, scanning interval 0.08mm, powder layer thickness 0.05mm, and scanning strategy of strip scanning with 67° rotation layer by layer. The volume energy density of the laser powder bed melting is 75J / mm². 3 .

[0092] S3: The material obtained by the above additive manufacturing is annealed at 1100℃ for 2 hours and then water quenched.

[0093] The X-ray diffraction pattern of the CoCrNi medium-entropy alloy matrix composite material prepared in this embodiment is as follows: Figure 3 As shown in the figure, 101 represents the composite material of this embodiment. The figure indicates that the medium-entropy alloy-based composite material obtained in this embodiment still contains partially molten WC particles in the FCC structure matrix.

[0094] The large-area scanning electron microscope image of the microstructure of the CoCrNi medium-entropy alloy matrix composite material prepared in this embodiment is shown below. Figure 4 As shown in the figure, the white particles are a certain amount of partially molten WC particles observed in backscattered electron (BSE) mode. These particles are uniformly distributed in the matrix, and most of them still maintain a good spherical shape.

[0095] The scanning electron microscope image of the partially molten WC particles and their surroundings in the microstructure of the CoCrNi medium-entropy alloy matrix composite material prepared in this embodiment is shown below. Figure 5 As shown, the line scan curve from the center of the partially molten WC particles to the matrix is ​​as follows: Figure 6 As shown. By Figure 5 and Figure 6 It can be seen that there is a transition zone with a width of 5μm~10μm between the partially molten WC particles and the matrix. The elements undergo obvious diffusion behavior in the transition zone and the matrix, forming a well-bonded diffusion interface.

[0096] The scanning electron microscope image of the carbides in the CoCrNi medium-entropy alloy matrix composite material prepared in this embodiment is shown below. Figure 7 As shown in the figure, the white particles at the submicron scale (100 nm ~ 400 nm) are carbides M precipitated during heat treatment, observed in secondary electron (SE) mode. 23 C6.

[0097] The room temperature tensile stress-strain curve of the CoCrNi medium-entropy alloy matrix composite material prepared in this embodiment is shown below. Figure 8 As shown in the figure, 101 represents the composite material of this embodiment. The figure shows that the tensile strength of this composite material is 1138 MPa, the yield strength is 783 MPa, and the elongation after fracture is 23.0%. The impact toughness is maintained at 53.4 J / cm². 2 Its hardness reaches 33.8 HRC.

[0098] The scanning electron microscope image of the room temperature tensile fracture surface of the CoCrNi medium-entropy alloy matrix composite material prepared in this embodiment is shown below. Figure 9 As shown, the scanning electron microscope image of the room temperature impact fracture surface is as follows. Figure 10 As shown, by Figure 9 and Figure 10 It can be seen that the tensile fracture and impact fracture of the composite material both exhibit typical ductile fracture characteristics. The tensile fracture forms a large number of small and deep equiaxed dimples under tensile normal stress, while the impact fracture forms a large number of small equiaxed dimples and a certain amount of elongated dimples under triaxial tensile stress at the notch.

[0099] The two-dimensional contour curve of the wear pit after room temperature friction and wear of the CoCrNi medium-entropy alloy-based composite material prepared in this embodiment is shown in the figure below. Figure 11 As shown in the figure, 101 represents the composite material of this embodiment; the overall scanning electron microscope image of the room temperature tribological wear surface of the composite material is shown below. Figure 12 As shown; a scanning electron microscope image of the localized wear pits on the room temperature friction and wear surface of the composite material is shown below. Figure 13 As shown. Combined with Figures 11 to 13 Calculations show that the volumetric wear rate of this composite material is only 2.5%. 10 -4 mm 3 / (N The wear pit morphology is mainly composed of a certain amount of wear debris and an area of ​​"oxide glaze" formed by the compaction of oxide wear debris during further wear.

[0100] Example 4 This embodiment provides a CoCrNi medium-entropy alloy-based composite material, which is obtained by additive manufacturing of a composite powder formed from CoCrNi medium-entropy alloy powder and WC powder via laser powder bed melting. The composite powder comprises 93 wt% CoCrNi medium-entropy alloy powder and 7 wt% WC powder.

[0101] The preparation method of this CoCrNi medium-entropy alloy-based composite material includes: S1: Weigh the CoCrNi medium-entropy alloy and WC powder according to the ratio and put them into a double cone high-efficiency mixer. Mechanically mix them at 30 rpm for 4 hours to obtain composite powder.

[0102] S2: The uniformly mixed composite powder is loaded into the powder supply system of the metal laser powder bed melting equipment. A high-purity argon protective atmosphere is established in the forming cavity. Laser powder bed melting is then performed under the following conditions: laser power 350W, scanning speed 1500mm / s, scanning interval 0.06mm, powder layer thickness 0.05mm, and scanning strategy of strip scanning with 67° rotation layer by layer. The volume energy density of the laser powder bed melting is 77.8J / mm². 3 .

[0103] S3: The material obtained by the above additive manufacturing is annealed at 1100℃ for 2 hours and then water quenched.

[0104] Testing revealed that the microstructure of the CoCrNi medium-entropy alloy matrix composite material prepared in this embodiment contained numerous partially molten WC particles and submicron-scale (100 nm~400 nm) carbides within the FCC-structured matrix. 23 C6.

[0105] Comparative Example 1 The difference between this comparative example and Example 3 is that the raw material used is only CoCrNi medium-entropy alloy powder, and WC powder is not used.

[0106] The X-ray diffraction pattern of the CoCrNi medium-entropy alloy material prepared in this comparative example is shown below. Figure 3 As shown in the figure, 102 represents the CoCrNi medium-entropy alloy material of this comparative example. The scanning electron microscope image of the microstructure of the CoCrNi medium-entropy alloy material prepared in this comparative example is shown below. Figure 14 As shown; Figure 3 and Figure 14 This indicates that the microstructure of the CoCrNi medium-entropy alloy material prepared in this comparative example is a typical FCC structure, and twins formed during the heat treatment process are also present.

[0107] The room temperature tensile stress-strain curve of the CoCrNi medium-entropy alloy material prepared in this comparative example is shown below. Figure 8 As shown in the figure, 102 represents the CoCrNi medium-entropy alloy material of this comparative example. The figure shows that the room temperature tensile strength of this CoCrNi medium-entropy alloy material is 842 MPa, the yield strength is 512 MPa, and the elongation after fracture is 53.6%. The impact toughness is tested to be 145.6 J / cm². 2 Its hardness is 15.9 HRC.

[0108] The scanning electron microscope image of the room temperature tensile fracture surface of the CoCrNi medium-entropy alloy material prepared in this comparative example is shown below. Figure 15 As shown; the room temperature impact fracture surface of the CoCrNi medium-entropy alloy material prepared in this comparative example is shown in the scanning electron microscope image. Figure 16 As shown. By Figure 15 and Figure 16 It can be seen that the tensile and impact fracture surfaces of this CoCrNi medium-entropy alloy material both exhibit typical ductile fracture characteristics. The tensile fracture surface forms a large number of small and deep equiaxed dimples under tensile normal stress, while the impact fracture surface forms a large number of elongated dimples under triaxial tensile stress at the notch.

[0109] The two-dimensional contour curve of the wear pit after room temperature friction and wear of the CoCrNi medium-entropy alloy material prepared in this comparative example is shown in the figure. Figure 11 As shown in the figure, 102 represents the CoCrNi medium-entropy alloy material of this comparative example; the overall scanning electron microscope image of the room temperature tribological wear surface of the CoCrNi medium-entropy alloy material prepared in this comparative example is shown below. Figure 17 As shown; Scanning electron microscope images of localized wear pits on the room temperature tribological surface of the CoCrNi medium-entropy alloy material prepared in this comparative example are shown below. Figure 18 As shown. Combined with Figure 11 , Figures 17 to 18 Calculations show that the volumetric wear rate of this composite material is only 8.0%. 10 -4 mm 3 / (N The wear pit morphology is mainly composed of a large amount of wear debris and oxide wear debris that are compacted during further wear, forming an area called "oxide glaze".

[0110] Comparative Example 2 The difference between this comparative example and Example 3 is that the composite powder includes 99.5 wt% CoCrNi medium-entropy alloy powder and 0.5 wt% WC powder.

[0111] Testing revealed that the microstructure of the CoCrNi medium-entropy alloy matrix composite material prepared in this comparative example exhibits a typical FCC structure, with almost no partially molten WC particles and carbide M particles observed in the matrix. 23 C6.

[0112] Comparative Example 3 The difference between this comparative example and Example 3 is that the composite powder includes 90 wt% CoCrNi medium-entropy alloy powder and 10 wt% WC powder.

[0113] Testing revealed that the microstructure of the CoCrNi medium-entropy alloy matrix composite material prepared in this comparative example contained numerous partially molten WC particles and submicron-scale (100 nm ~ 400 nm) carbides within the FCC-structured matrix. 23 C6.

[0114] Comparative Example 4 The difference between this comparative example and Example 3 is that the WC powder used has a different sphericity; specifically, irregular WC powder with a sphericity of only about 80% is used.

[0115] Testing revealed that the microstructure of the CoCrNi medium-entropy alloy matrix composite material prepared in this comparative example still contained a certain number of partially molten WC particles and submicron-scale (100nm~400nm) carbides within the FCC-structured matrix. 23C6 only shows poor interfacial bonding between partially molten WC particles and the matrix, with obvious cracks visible at the interface and in the unmelted area.

[0116] Comparative Example 5 The difference between this comparative example and Example 3 is that the laser power for laser powder bed melting is 400W, and correspondingly, the volume energy density is 100J / mm². 3 .

[0117] Testing revealed that the microstructure of the CoCrNi medium-entropy alloy matrix composite material prepared in this comparative example still contained a certain number of partially molten WC particles and submicron-scale (100nm~400nm) carbides within the FCC-structured matrix. 23 C6, wherein the number of partially molten WC particles is less than in Example 3, and carbide M 23 The number of C6 is greater than in Example 3.

[0118] Comparative Example 6 The difference between this comparative example and Example 3 is that the scanning speed of the laser powder bed melting process is 1800 mm / s, and the corresponding volume energy density is 41.6 J / mm². 3 .

[0119] Testing revealed that the microstructure of the CoCrNi medium-entropy alloy matrix composite material prepared in this comparative example contained more partially molten WC particles and fewer submicron-scale (100 nm~400 nm) carbides in the FCC structure matrix. 23 C6 has poor interfacial bonding between partially molten WC particles and the matrix, with obvious cracks visible at the interface. At the same time, the microstructure contains a certain amount of typical defects such as incomplete fusion, pores, and cracks.

[0120] Comparative Example 7 The difference between this comparative example and Example 3 is that the scanning distance for laser powder bed melting is 0.15 mm, and correspondingly, the volume energy density is 40 J / mm². 3 .

[0121] Testing revealed that the microstructure of the CoCrNi medium-entropy alloy matrix composite material prepared in this comparative example contained more partially molten WC particles and fewer submicron-scale (100 nm~400 nm) carbides in the FCC structure matrix. 23 C6 has poor interfacial bonding between partially molten WC particles and the matrix, with obvious cracks visible at the interface. At the same time, the microstructure contains a certain amount of typical defects such as incomplete fusion, pores, and cracks.

[0122] Comparative Example 8 The difference between this comparative example and Example 3 is that the thickness of the powder bed formed by laser powder bed melting is 0.1 mm, and correspondingly, the volume energy density is 37.5 J / mm². 3 .

[0123] Testing revealed that the microstructure of the CoCrNi medium-entropy alloy matrix composite material prepared in this comparative example contained more partially molten WC particles and fewer submicron-scale (100 nm~400 nm) carbides in the FCC structure matrix. 23 C6 has poor interfacial bonding between partially molten WC particles and the matrix, with obvious cracks visible at the interface. At the same time, the microstructure contains a certain amount of typical defects such as incomplete fusion, pores, and cracks.

[0124] Comparative Example 9 The difference between this comparative example and Example 3 is that the annealing temperature is 1200°C.

[0125] Testing revealed that the microstructure of the CoCrNi medium-entropy alloy matrix composite material prepared in this comparative example still contained a certain amount of partially molten WC particles within the FCC-structured matrix. Simultaneously, excessive W and C elements dissolved in the matrix formed excessive carbides (M). 23 C6, and the size has increased (reaching 300nm~1000nm).

[0126] Test case The properties of the CoCrNi medium-entropy alloy-based composite materials and CoCrNi medium-entropy alloy materials prepared in Examples 1-4 and Comparative Examples 1-9 were compared, and the results are shown in Table 1.

[0127] In this paper, tensile strength, yield strength, and elongation after fracture were tested according to GB / T 228.1-2021 Metallic materials - Tensile testing - Part 1: Test method at room temperature; impact toughness was tested according to GB / T 229-2020 Metallic materials - Charpy pendulum impact test method; hardness was tested according to GB / T 230.1-2018 Metallic materials - Rockwell hardness test - Part 1: Test method; and volumetric wear rate was tested according to ASTM G98-17 Standard Test Method for Galling Resistance of Materials.

[0128] Table 1 Performance Test Results

[0129] As shown in Table 1, the CoCrNi medium-entropy alloy-based composite materials prepared in Examples 1-4 of this invention have tensile strengths of 880 MPa to 1215 MPa, yield strengths of 537 MPa to 897 MPa, elongation after fracture of 11.2% to 53.5%, and impact toughness of 32.1 J / cm². 2 ~141.2 J / cm 2 Its hardness ranges from 24.9 HRC to 36.7 HRC, and its volumetric wear rate is 2.1%. 10 -4 mm 3 / (N m)~7.5 10 -4 mm 3 / (N Compared with the CoCrNi medium-entropy alloy material prepared in Comparative Example 1, the CoCrNi medium-entropy alloy-based composite material prepared in the above embodiments has a tensile strength increased by 4%~44%, a yield strength increased by 4%~75%, a hardness increased by 57%~130%, and a volume wear rate reduced by 6%~73%, while still maintaining good toughness (reflected in higher elongation after fracture and impact toughness values).

[0130] Compared with Example 3, the WC content in Comparative Examples 2 and 3 was too low or too high, resulting in a decrease in the overall room temperature performance of the composite material; the use of WC powder with poor sphericity in Comparative Example 4 resulted in a decrease in the overall room temperature performance of the composite material; the laser powder bed melting and forming conditions in Comparative Examples 5-8 were inappropriate, resulting in a decrease in the overall room temperature performance of the composite material; and the heat treatment temperature in Comparative Example 9 was inappropriate, resulting in a decrease in the overall room temperature performance of the composite material.

[0131] In summary, this invention, by introducing spherical WC particles and precisely controlling the LPBF process, achieves a simultaneous improvement in the strength and toughness of the composite material through multi-level and multi-scale effects, including fine-grained strengthening, second-phase strengthening, load transfer strengthening, and solid solution strengthening. Its wear resistance mainly stems from the support of the hard phase, strong interfacial bonding, adaptive surface formation, and enhanced deformation resistance of the matrix itself. These mechanisms work together to enable the composite material to exhibit excellent service performance under harsh friction and wear conditions.

[0132] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A CoCrNi medium-entropy alloy-based composite material, characterized in that, The CoCrNi medium-entropy alloy-based composite material is obtained by additive manufacturing of a composite powder formed by CoCrNi medium-entropy alloy powder and WC powder through laser powder bed melting. The CoCrNi medium-entropy alloy matrix composite material comprises a matrix with an FCC structure, wherein WC particles and submicron carbides M are distributed in the matrix. 23 C6; wherein the WC particles are in a partially molten state, and there is an elemental transition layer between the WC particles and the matrix.

2. The CoCrNi medium-entropy alloy-based composite material according to claim 1, characterized in that, The composite powder has at least one of the following characteristics: Feature 1: The mass ratio of the CoCrNi medium-entropy alloy powder to the WC powder is 93:7 to 99:1; preferably, the mass ratio of the CoCrNi medium-entropy alloy powder to the WC powder is 95:5; Feature 2: The particle size of the CoCrNi medium-entropy alloy powder is 15μm~53μm; Feature 3: The particle size of the WC powder is 15μm~53μm; Feature 4: The sphericity of the WC powder is not less than 95%.

3. The CoCrNi medium-entropy alloy-based composite material according to claim 1, characterized in that, The width of the elemental transition layer is 5μm~10μm.

4. The CoCrNi medium-entropy alloy-based composite material according to claim 1, characterized in that, Submicron carbide M 23 The size of C6 is 100nm~400nm.

5. The CoCrNi medium-entropy alloy-based composite material according to any one of claims 1 to 4, characterized in that, The CoCrNi medium-entropy alloy-based composite material also has at least one of the following characteristics: Feature 5: The tensile strength of the CoCrNi medium-entropy alloy-based composite material is 880MPa~1215MPa; Feature 6: The yield strength of the CoCrNi medium-entropy alloy-based composite material is 537MPa~897MPa; Feature 7: The elongation after fracture of the CoCrNi medium-entropy alloy-based composite material is 11.2%~53.5%; Feature 8: The impact toughness of the CoCrNi medium-entropy alloy matrix composite material is 32.1 J / cm. 2 ~141.2 J / cm 2 ; Feature 9: The hardness of the CoCrNi medium-entropy alloy-based composite material is 24.9 HRC to 36.7 HRC; Feature 10: The volumetric wear rate of the CoCrNi medium-entropy alloy-based composite material is 2.1%. 10 -4 mm 3 / (N m)~7.5 10 - 4 mm 3 / (N m).

6. An additive manufacturing method for a CoCrNi medium-entropy alloy-based composite material as described in any one of claims 1 to 5, characterized in that, The process includes the following steps: additive manufacturing of a composite powder formed by CoCrNi medium-entropy alloy powder and WC powder using laser powder bed melting.

7. The additive manufacturing method according to claim 6, characterized in that, The composite powder is obtained by mechanically mixing the CoCrNi medium-entropy alloy powder and the WC powder at 10 rpm to 30 rpm for 4 h to 10 h. Preferably, the composite powder is dried before being subjected to laser powder bed melting and forming.

8. The additive manufacturing method according to claim 6, characterized in that, The conditions for laser powder bed melting and forming include: laser power of 150W~350W, scanning speed of 500mm / s~1500mm / s, scanning spacing of 0.06mm~0.12mm, powder layer thickness of 0.03mm~0.08mm, and scanning strategy of strip scanning or partition scanning with layer-by-layer rotation. Preferably, the volume energy density of the laser powder bed fusion molding is 60 J / mm². 3 ~80J / mm 3 .

9. The additive manufacturing method according to any one of claims 6 to 8, characterized in that, The material obtained from additive manufacturing is heat-treated. Preferably, the heat treatment includes: annealing at 1000℃~1100℃ for 1h~3h followed by water quenching or oil quenching; Preferably, the heat treatment includes annealing at 1100°C for 2 hours followed by water quenching.

10. The application of a CoCrNi medium-entropy alloy-based composite material as described in any one of claims 1 to 5, characterized in that, The CoCrNi medium-entropy alloy-based composite material is used to prepare lightweight load-bearing components for aerospace, high-performance wear-resistant parts, and / or high-end tool molds.

Images