High-entropy alloy particle reinforced layered structure aluminum-based composite material and preparation process thereof

Abstract

The invention discloses a high-entropy alloy particle reinforced lamellar structure aluminum matrix composite material and a preparation technology of the high-entropy alloy particle reinforced lamellar structure aluminum matrix composite material. The high-entropy alloy comprises a FeCoCrNi system, a FeCoMnNi system, an AlFeCoCrNi system, an AlTi system and the like, and the aluminum alloy comprises AlSi10Mg, AlSi12, AlSi7Mg and the like. The method comprises the steps that firstly, based on the selective laser melting forming technology, aluminum alloy powder is printed into a layered topological structure frame; then, the layered frame is filled with high-entropy alloy powder, and a prefabricated body is obtained; and finally, a pressure infiltration technology is adopted, molten aluminum alloy is pressed and infiltrated into the prefabricated body by utilizing the characteristic that a high-entropy alloy and an aluminum alloy matrix have natural wettability, and the high-entropy alloy particle reinforced aluminum-based composite material of a layered structure is obtained. The thought of the invention comes from a multilayer structure of shells, the prepared material is high in density, good in obdurability and high in interface bonding strength, and the preparation method is novel and has a good application prospect.

Description

Technical Field

[0001] The present invention belongs to the field of metal matrix composite materials, and specifically relates to a high entropy alloy particle reinforced layered aluminum matrix composite material and its preparation process Background Art

[0002] In recent years, aluminum-based composite materials and their reinforcement phases have become a research hotspot. Many researchers consider using metal particles such as metal elements, quasicrystals, and amorphous alloys as reinforcement materials for aluminum alloys to improve the interface between the reinforcement particles and the aluminum alloy matrix. As a new type of alloy material, high entropy alloys have the characteristics of high strength, high hardness, and good high-temperature stability. At the same time, they have good wettability and compatibility with aluminum alloys, making them very suitable as reinforcement phases for aluminum alloys.

[0003] The pearl layer of shells has a biological structure similar to that of a layered structure. In its microstructure, calcium carbonate aragonite sheets overlap each other. The tensile strength of the pearl layer is more than twice that of calcium carbonate, and its fracture toughness is 3,000 times that of calcium carbonate, perfectly achieving the goal of improving both strength and toughness. In view of the fact that aluminum-based composite materials often have a serious decrease in plasticity while increasing their strength, a breakthrough in their comprehensive mechanical properties can be achieved by imitating the layered structure of the pearl layer of shells.

[0004] The present invention uses the laser selective melting (SLM) technology to print the aluminum alloy frame with a layered structure, which can solve the processing and manufacturing problems of complex structural parts such as porous, hollow, and dot matrix that are difficult to solve with traditional manufacturing technology. This technology accurately manufactures layered materials with specific sizes and structures by controlling the thickness and shape of each layer of the printed material with high precision. This layered material has high density, high interlayer bonding strength, and excellent mechanical properties. In addition, it has a high degree of freedom in structural design, flexible adjustment of printing parameters, and fast and convenient molding, which opens up broad prospects for the innovative design and manufacturing of high-performance products.

[0005] At present, there is no report on using high entropy alloys as reinforcement phases and laser selective melting technology to prepare layered aluminum-based composites. Summary of the invention

[0006] The present invention provides a high entropy alloy particle reinforced layered aluminum-based composite material and a preparation process thereof. The method uses aluminum-silicon alloy powder to print an alloy frame with a layered structure; utilizes the good fluidity of the block molten alloy to squeeze the molten aluminum alloy liquid into the aluminum alloy frame filled with high entropy alloy powder; utilizes the natural interface wettability of the high entropy alloy and the aluminum alloy matrix to make it a reinforcing phase of the aluminum-based composite material; the layered aluminum-based composite material of the present invention has comprehensive properties such as high strength and high toughness.

[0007] The present invention is specifically implemented according to the following steps:

[0008] (1) Aluminum alloy frame design and SLM (Selective Laser Melting, SLM) printing: First, design layered topological structure frames of different shapes, sizes, and thicknesses; then load the vacuum-dried aluminum alloy powder into the printer powder supply bin, spread the powder evenly on the printer powder spreading bin, adjust the printing parameters according to the two-dimensional slices of the three-dimensional model input by the printer, and obtain the aluminum alloy layered topological structure frame after printing;

[0009] (2) Preparation of preform: First, the aluminum alloy topological structure frame obtained in step (1) is tightly and evenly filled with high entropy alloy powder to obtain a preform, and then the preform is fixed as a whole in a cylindrical graphite groove with a suitable size and a hole, and the graphite groove and the preform cooperate with each other;

[0010] (3) Melting aluminum alloy and preheating preform: Weigh a certain mass of aluminum alloy, put it into a melting furnace for heating, melting, heat preservation, and refining to obtain aluminum alloy melt. Put the preform obtained in step (2) together with the graphite mold into a steel mold, and heat and keep it warm;

[0011] (4) Preparation of layered aluminum-based composite materials: The aluminum alloy melt obtained in step (3) is cast into a steel mold using a hydraulic press, and then pressure infiltration is performed. After the aluminum alloy melt is completely infiltrated into the preform under pressure, a layered aluminum-based composite material reinforced with high entropy alloy particles is obtained after cooling and solidification.

[0012] In the above method, the layered topological structure framework designed in step (1) comprises various polygons, such as triangles, quadrilaterals, hexagons, etc., with side lengths ranging from 1 mm to 10 mm and thicknesses ranging from 0.1 mm to 1 mm.

[0013] In the above method, in step (1), the selected aluminum alloy powder is mainly an Al-Si alloy suitable for laser selective melting (SLM) technology, and the main materials include AlSi10Mg, AlSi12, AlSi7Mg, etc.; the aluminum alloy powder particle size range is 10 to 100 μm, and the purity range is 99% to 99.99%.

[0014] In the above method, in step (1), the aluminum alloy powder is placed in a vacuum drying oven and heated to 60-100° C., and then kept warm and dried for 2-10 hours.

[0015] In the above method, the printing parameters of the layered structure frame in step (1) are: laser power is 200-400W, scanning speed is 1100-1400mm / s, scanning strategy is that the laser scanning direction of two adjacent layers is 60°-70°, scanning spacing is 100-150μm, and powder layer thickness is 10-100μm.

[0016] In the above method, the high entropy alloy powder selected in step (2) includes FeCoCrNi series, FeCoMnNi series, AlFeCoCrNi series, AlTi series, etc. The particle size of the high entropy alloy powder ranges from 10 to 100 μm, and the purity ranges from 99% to 99.99%.

[0017] In the above method, the hole of the cylindrical graphite groove in step (2) is circular with a diameter of 0.1-2 mm.

[0018] In the above method, the composition of the aluminum alloy block in step (3) is consistent with or similar to the composition of the aluminum alloy powder in step (1).

[0019] In the above method, the mass of the aluminum alloy in step (3) is 3-10 times the mass of the preform.

[0020] In the above method, in step (3), the aluminum alloy block is heated to 100-300°C above its melting point at a heating rate of 5-10°C / min and kept warm for 0.5-4h.

[0021] In the above method, in step (3), the preform is heated to a temperature of 200-600° C. and kept warm for 2-4 hours.

[0022] In the above method, during the pressure infiltration process of step (4), the pressure is set to 40-120 MPa, the pressure holding time is set to 2-15 min, and the cooling time is set to 2-15 min.

[0023] Principle of the present invention:

[0024] The present invention designs an aluminum alloy frame with a multi-layer topological structure by imitating the nacre structure of shells in nature, and fixes hard high-entropy alloy particles as reinforcing phase particles in the aluminum alloy frame structure, thereby achieving the alternating effects of strength and plasticity, breaking through the strength-plasticity "bottleneck" of conventional homogeneous particle-reinforced aluminum-based composite materials; at the same time, the layered aluminum-based composite material is prepared by a liquid state process, has a high density, and is suitable for use as a structural or functional / structural material.

[0025] Technical features and advantages of the present invention:

[0026] 1. The present invention utilizes laser selective melting forming technology to prepare layered aluminum alloy frames of different shapes, sizes and thicknesses. The surface roughness of the finished frames is low and the density is as high as 99%. Different types of high entropy alloy powders can be selected and filled into the frames to form preforms. The process is flexible and suitable for industrial production and application.

[0027] 2. The present invention utilizes pressure infiltration technology, which can form quickly, avoid casting defects such as shrinkage, shrinkage and pores produced by gravity casting process, and inhibit the generation of harmful interface reaction products. Under pressure, the aluminum liquid can completely penetrate into the high entropy alloy powder, so that the material has a high density and good interface bonding.

[0028] 3. The present invention utilizes the natural interface wettability between the high entropy alloy and the aluminum alloy matrix, and uses high entropy alloy particles as reinforcements for the aluminum-based composite material, thereby further improving the interface bonding strength; at the same time, different types of high entropy alloys can also be selected to meet the performance requirements of the composite material under different service conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 Diagram of aluminum alloy frames with different characteristics formed by SLM in Examples 1, 4, and 7.

[0030] Figure 2 This is a diagram of the preform of Example 1.

[0031] Figure 3 This is a finished product picture of the layered aluminum-based composite material obtained after pressure infiltration of the preform in Example 1.

[0032] Figure 4 This is the low-magnification microstructure morphology of the layered aluminum-based composite material reinforced with high entropy alloy particles in Example 2.

[0033] Figure 5 This is the high-magnification microstructure morphology of the layered aluminum-based composite material reinforced with high entropy alloy particles in Example 2.

[0034] Figure 6 This is the compressive stress-strain curve of the layered aluminum-based composite material reinforced with high entropy alloy particles in Example 2. DETAILED DESCRIPTION

[0035] The present invention will be further described in detail below in conjunction with specific embodiments, but the embodiments of the present invention are not limited thereto. For process parameters not particularly noted, conventional techniques may be used.

[0036] Example 1

[0037] (1) Aluminum alloy frame design and SLM printing: First, a rectangular structure with a thickness of 0.2 mm and a single frame length and width of 2 × 1 mm was designed. Then, AlSi10Mg alloy powder that had been kept at 60 ° C for 6 h in a vacuum state was placed in the printer powder supply bin. The printer laser power was set to 350 W, the scanning speed was set to 1100 mm / s, and the scanning strategy was that the laser scanning direction of the two adjacent layers was 67°, the scanning spacing was 150 μm, and the powder layer thickness was 30 μm. (The alloy powder particle size and powder layer thickness are similar) The printed frame is as follows Figure 1 shown.

[0038] (2) Preform preparation: First, Fe 25 Co 25 Cr 25 Ni 25 The high entropy alloy powder is tightly and evenly filled in the AlSi10Mg aluminum alloy topological structure frame to obtain a preform; then the preform is fixed as a whole in a cylindrical graphite groove with holes. The graphite groove and the preform cooperate with each other. The hole of the groove is circular with a diameter of 0.2mm. The preform is shown in the figure Figure 2 shown.

[0039] (3) Melting of aluminum alloy and preform preheating: Weigh an AlSi10Mg block with a mass three times that of the preform, place it in a melting furnace and heat it at a rate of 10°C / min to 300°C above its melting point, then keep it warm for 4 h to obtain an aluminum alloy melt; place the preform together with the graphite mold into a steel mold, heat the preform to 370°C, and keep it warm for 3 h.

[0040] (4) Preparation of layered aluminum-based composite materials: A hydraulic press is used to cast the aluminum alloy melt into a steel mold, and then pressure infiltration is performed. The aluminum alloy melt is completely infiltrated into the preform under pressure, and after solidification and cooling, a layered aluminum-based composite material reinforced with high entropy alloy particles is obtained. During pressure infiltration, the pressure is set to 70 MPa, the holding time is set to 3 min, and the cooling time is set to 5 min. The finished layered aluminum-based composite material obtained after pressure infiltration of the preform is as follows Figure 3 shown.

[0041] Example 2

[0042] (1) Aluminum alloy frame design and SLM printing: First, a rectangular structure with a thickness of 0.4 mm and a single frame length and width of 6×3 mm was designed. Then, AlSi10Mg alloy powder that had been kept at 70°C for 7 hours under vacuum was placed in the printer powder supply bin. The printer laser power was set to 355W, the scanning speed was set to 1200mm / s, and the scanning strategy was that the laser scanning direction of the two adjacent layers was 70°, the scanning spacing was 100μm, and the powder layer thickness was 40μm. (The alloy powder particle size and powder layer thickness were similar)

[0043] (2) Preform preparation: First, Al 10 (Fe 25 Co 25 Cr 25 Ni 25 ) 90 The high entropy alloy powder is tightly and evenly filled in the AlSi10Mg aluminum alloy topological structure frame to obtain a preform; then the preform is fixed as a whole in a cylindrical graphite groove with holes, the graphite groove and the preform cooperate with each other, and the hole of the groove is circular with a diameter of 0.3mm.

[0044] (3) Melting of aluminum alloy and preform preheating: Weigh an AlSi10Mg block with a mass four times that of the preform, place it in a melting furnace and heat it at a rate of 8°C / min to a melting temperature of 265°C, then keep it at that temperature for 3.5 h to obtain an aluminum alloy melt; place the preform together with the graphite mold into a steel mold, heat the preform to 330°C, and keep it at that temperature for 4 h.

[0045] (4) Preparation of layered aluminum matrix composite materials: A hydraulic press is used to cast the aluminum alloy melt into a steel mold, and then pressure infiltration is performed. The aluminum alloy melt is completely infiltrated into the preform under pressure, and after cooling and solidification, a layered aluminum matrix composite material reinforced with high entropy alloy particles is obtained. The pressure during pressure infiltration is set to 75 MPa, and the holding time is set to 6 min. The cooling time is set to 6 min. The low-magnification and high-magnification microstructure morphology of the layered aluminum matrix composite material is shown in Figure 2. Figure 4 , Figure 5 The mechanical properties are shown in Figure 6 shown.

[0046] Example 3

[0047] (1) Aluminum alloy frame design and SLM printing: First, a rectangular structure with a thickness of 0.3 mm and a single frame length and width of 4×2 mm was designed. Then, AlSi10Mg alloy powder that had been kept at 100°C for 8 hours under vacuum was placed in the printer powder supply bin. The printer laser power was set to 390 W, the scanning speed was set to 1150 mm / s, and the scanning strategy was that the laser scanning direction of the two adjacent layers was 78°, the scanning spacing was 120 μm, and the powder layer thickness was 45 μm. (The alloy powder particle size and powder layer thickness were similar)

[0048] (2) Preform preparation: First, Fe 20 Co 20 Cr 20 Ni 20 Mn 20The high entropy alloy powder is tightly and evenly filled in the AlSi10Mg aluminum alloy topological structure frame to obtain a preform; then the preform is fixed as a whole in a cylindrical graphite groove with holes, the graphite groove and the preform cooperate with each other, and the hole of the groove is circular with a diameter of 0.4 mm.

[0049] (3) Melting of aluminum alloy and preform preheating: Weigh an AlSi10Mg block with a mass 5 times that of the preform, place it in a melting furnace and heat it at a rate of 5°C / min to a melting temperature of 200°C, then keep it at that temperature for 1.5 h to obtain an aluminum alloy melt; place the preform together with the graphite mold into a steel mold, heat the preform to 350°C, and keep it at that temperature for 2.5 h.

[0050] (4) Preparation of layered aluminum matrix composite materials: A hydraulic press is used to cast the aluminum alloy melt into a steel mold, and then pressure infiltration is performed. The aluminum alloy melt is completely infiltrated into the preform under pressure, and after cooling and solidification, a layered aluminum matrix composite material reinforced with high entropy alloy particles is obtained. The pressure during pressure infiltration is set to 80 MPa, and the holding time is set to 7 min. The cooling time is set to 7 min.

[0051] Example 4

[0052] (1) Aluminum alloy frame design and SLM printing: First, a regular triangle structure with a thickness of 0.4 mm and a single frame side length of 3.5 mm was designed. Then, AlSi12 alloy powder that had been kept at 90°C for 9 hours under vacuum was placed in the printer powder supply bin. The printer laser power was set to 380 W, the scanning speed was set to 1175 mm / s, and the scanning strategy was that the laser scanning direction of the two adjacent layers was 79°, the scanning spacing was 140 μm, and the powder layer thickness was 50 μm. (The alloy powder particle size and powder layer thickness are similar) The printed frame is shown in the figure. Figure 2 shown.

[0053] (2) Preform preparation: First, Al 20 Fe 20 Co 20 Cr 20 Ni 20 The high entropy alloy powder is tightly and evenly filled in the AlSi12 aluminum alloy topological structure frame to obtain a preform; then the preform is fixed as a whole in a cylindrical graphite groove with holes, the graphite groove and the preform cooperate with each other, and the hole of the groove is circular with a diameter of 0.45 mm.

[0054] (3) Melting of aluminum alloy and preheating of preform: Weigh an AlSi12 block with a mass 5.5 times that of the preform, place it in a melting furnace and heat it at a rate of 7°C / min to a melting temperature of 250°C, then keep it at that temperature for 3.5 h to obtain an aluminum alloy melt; place the preform together with the graphite mold into a steel mold, heat the preform to 380°C, and keep it at that temperature for 3 h.

[0055] (4) Preparation of layered aluminum matrix composite materials: A hydraulic press is used to cast the aluminum alloy melt into a steel mold, and then pressure infiltration is performed. The aluminum alloy melt is completely infiltrated into the preform under pressure, and after cooling and solidification, a layered aluminum matrix composite material reinforced with high entropy alloy particles is obtained. The pressure during pressure infiltration is set to 85 MPa, and the holding time is set to 8 min. The cooling time is set to 8 min.

[0056] Example 5

[0057] (1) Aluminum alloy frame design and SLM printing: First, a regular triangle structure with a thickness of 0.7 mm and a single frame length of 4 mm was designed. Then, AlSi12 alloy powder that had been kept at 80°C for 2 hours under vacuum was placed in the printer powder supply bin. The printer laser power was set to 250 W, the scanning speed was set to 1200 mm / s, and the scanning strategy was that the laser scanning direction of the two adjacent layers was 77°, the scanning spacing was 105 μm, and the powder layer thickness was 55 μm. (The alloy powder particle size and powder layer thickness were similar)

[0058] (2) Preform preparation: First, Fe 20 Co 20 Mn 20 Ni 20 Cu 20 The high entropy alloy powder is tightly and evenly filled in the AlSi12 aluminum alloy topological structure frame to obtain a preform; then the preform is fixed as a whole in a cylindrical graphite groove with holes, the graphite groove and the preform cooperate with each other, and the hole of the groove is circular with a diameter of 0.5 mm.

[0059] (3) Melting of aluminum alloy and preheating of preform: Weigh an AlSi12 block with a mass six times that of the preform, place it in a melting furnace and heat it at a rate of 6°C / min to a melting temperature of 270°C, then keep it warm for 1.5 h to obtain an aluminum alloy melt; place the preform together with the graphite mold into a steel mold, heat the preform to 400°C, and keep it warm for 3 h.

[0060] (4) Preparation of layered aluminum matrix composite materials: A hydraulic press is used to cast the aluminum alloy melt into a steel mold, and then pressure infiltration is performed. The aluminum alloy melt is completely infiltrated into the preform under pressure, and after cooling and solidification, a layered aluminum matrix composite material reinforced with high entropy alloy particles is obtained. During pressure infiltration, the pressure is set to 90 MPa, the holding time is set to 11 min, and the cooling time is set to 9 min.

[0061] Example 6

[0062] (1) Aluminum alloy frame design and SLM printing: First, a regular triangle structure with a thickness of 1 mm and a single frame length of 5 mm was designed. Then, AlSi12 alloy powder that had been kept at 75°C for 3 hours under vacuum was placed in the printer powder supply bin. The printer laser power was set to 200 W, the scanning speed was set to 1250 mm / s, and the scanning strategy was that the laser scanning direction of the two adjacent layers was 69°, the scanning spacing was 110 μm, and the powder layer thickness was 60 μm. (The alloy powder particle size and powder layer thickness were similar)

[0063] (2) Preform preparation: First, Fe 20 Co 20 Cr 20 Ni 20 Mo 20 The high entropy alloy powder is tightly and evenly filled in the AlSi12 aluminum alloy topological structure frame to obtain a preform; then the preform is fixed as a whole in a cylindrical graphite groove with holes, the graphite groove and the preform cooperate with each other, and the hole of the groove is circular with a diameter of 0.6 mm.

[0064] (3) Melting of aluminum alloy and preform preheating: Weigh an AlSi12 block with a mass that is 7 times the mass of the preform, place it in a melting furnace and heat it at a rate of 10°C / min to a melting temperature of 280°C, then keep it warm for 1 hour to obtain an aluminum alloy melt; place the preform together with the graphite mold into a steel mold, heat the preform to 520°C, and keep it warm for 3 hours.

[0065] (4) Preparation of layered aluminum matrix composite materials: A hydraulic press is used to cast the aluminum alloy melt into a steel mold, and then pressure infiltration is performed. The aluminum alloy melt is completely infiltrated into the preform under pressure, and after cooling and solidification, a layered aluminum matrix composite material reinforced with high entropy alloy particles is obtained. During pressure infiltration, the pressure is set to 95 MPa, the holding time is set to 6 min, and the cooling time is set to 6 min.

[0066] Example 7

[0067] (1) Aluminum alloy frame design and SLM printing: First, a regular hexagonal structure with a thickness of 0.4 mm and a single frame size of 2 mm was designed. Then, AlSi7Mg alloy powder that had been kept at 85°C for 4 hours under vacuum was placed in the printer powder supply bin. The printer laser power was set to 370 W, the scanning speed was set to 1300 mm / s, and the scanning strategy was that the laser scanning direction of the two adjacent layers was 75°, the scanning spacing was 115 μm, and the powder layer thickness was 35 μm. (The alloy powder particle size and powder layer thickness are similar) The printed frame is as follows Figure 2 shown.

[0068] (2) Preform preparation: First, Al 20 Ti 20 Cr20 Ni 20 Cu 20 The high entropy alloy powder is tightly and evenly filled in the AlSi7Mg aluminum alloy topological structure frame to obtain a preform; then the preform is fixed as a whole in a cylindrical graphite groove with holes, the graphite groove and the preform cooperate with each other, and the hole of the groove is circular with a diameter of 0.65 mm.

[0069] (3) Melting of aluminum alloy and preform preheating: Weigh an AlSi7Mg block with a mass 4.5 times that of the preform, place it in a melting furnace and heat it at a rate of 7°C / min to a melting temperature of 290°C, then keep it at that temperature for 2 h to obtain an aluminum alloy melt; place the preform together with the graphite mold into a steel mold, heat the preform to 560°C, and keep it at that temperature for 4 h.

[0070] (4) Preparation of layered aluminum matrix composite materials: A hydraulic press is used to cast the aluminum alloy melt into a steel mold, and then pressure infiltration is performed. The aluminum alloy melt is completely infiltrated into the preform under pressure, and after cooling and solidification, a layered aluminum matrix composite material reinforced with high entropy alloy particles is obtained. During pressure infiltration, the pressure is set to 100 MPa, the holding time is set to 5 min, and the cooling time is set to 7 min.

[0071] Example 8

[0072] (1) Aluminum alloy frame design and SLM printing: First, a regular hexagonal structure with a thickness of 0.6 mm and a single frame size of 4 mm was designed. Then, AlSi7Mg alloy powder that had been kept at 95°C for 5 hours under vacuum was placed in the printer powder supply bin. The printer laser power was set to 360 W, the scanning speed was set to 1350 mm / s, and the scanning strategy was that the laser scanning direction of the two adjacent layers was 76°, the scanning spacing was 125 μm, and the powder layer thickness was 30 μm. (The alloy powder particle size and powder layer thickness were similar)

[0073] (2) Preform preparation: First, Fe 20 Co 20 Cr20Ni 20 Cu 20 The high entropy alloy powder is tightly and evenly filled in the AlSi7Mg aluminum alloy topological structure frame to obtain a preform; then the preform is fixed as a whole in a cylindrical graphite groove with holes, the graphite groove and the preform cooperate with each other, and the hole of the groove is circular with a diameter of 0.7 mm.

[0074] (3) Melting of aluminum alloy and preform preheating: Weigh an AlSi7Mg block with a mass 5 times that of the preform, place it in a melting furnace and heat it at a rate of 8°C / min to a melting temperature of 140°C, then keep it warm for 4 h to obtain an aluminum alloy melt; place the preform together with the graphite mold into a steel mold, heat the preform to 580°C, and keep it warm for 4 h.

[0075] (4) Preparation of layered aluminum matrix composite materials: A hydraulic press is used to cast the aluminum alloy melt into a steel mold, and then pressure infiltration is performed. The aluminum alloy melt is completely infiltrated into the preform under pressure, and after cooling and solidification, a layered aluminum matrix composite material reinforced with high entropy alloy particles is obtained. During pressure infiltration, the pressure is set to 105 MPa, the holding time is set to 9 min, and the cooling time is set to 8 min.

[0076] Example 9

[0077] (1) Aluminum alloy frame design and SLM printing: First, a regular hexagonal structure with a thickness of 0.8 mm and a single frame size of 6 mm was designed. Then, AlSi7Mg alloy powder that had been kept at 65°C for 6 hours under vacuum was placed in the printer powder supply bin. The printer laser power was set to 365W, the scanning speed was set to 1400mm / s, and the scanning strategy was that the laser scanning direction of the two adjacent layers was 77°, the scanning spacing was 135μm, and the powder layer thickness was 35μm. (The alloy powder particle size and powder layer thickness were similar)

[0078] (2) Preform preparation: First, Al 20 Ti 20 Cr 20 Co 20 Cu 20 The high entropy alloy powder is tightly and evenly filled in the AlSi7Mg aluminum alloy topological structure frame to obtain a preform; then the preform is fixed as a whole in a cylindrical graphite groove with holes, the graphite groove and the preform cooperate with each other, and the hole of the groove is circular with a diameter of 0.8 mm.

[0079] (3) Melting of aluminum alloy and preheating of preform: Weigh an AlSi7Mg block with a mass 3.5 times that of the preform, place it in a melting furnace and heat it at a rate of 9°C / min to a melting temperature of 120°C, then keep it warm for 1 hour to obtain an aluminum alloy melt; place the preform together with the graphite mold into a steel mold, heat the preform to 600°C, and keep it warm for 3.5 hours.

[0080] (4) Preparation of layered aluminum matrix composite materials: A hydraulic press is used to cast the aluminum alloy melt into a steel mold, and then pressure infiltration is performed. The aluminum alloy melt is completely infiltrated into the preform under pressure, and after cooling and solidification, a layered aluminum matrix composite material reinforced with high entropy alloy particles is obtained. The pressure during pressure infiltration is set to 110 MPa, and the holding time is set to 10 min. The cooling time is set to 9 min.

[0081] The above embodiments are only preferred implementation modes of the present invention and are only used to explain the present invention rather than to limit the present invention. Any changes, substitutions, modifications, etc. made by those skilled in the art without departing from the spirit of the present invention should fall within the scope of protection of the present invention.

Claims

1. A process for preparing a high entropy alloy particle reinforced layered aluminum-based composite material, characterized in that: The steps include: (1) Aluminum alloy frame design and SLM printing: Design layered topological structure frames of different shapes, sizes, and thicknesses; then load the vacuum-dried aluminum alloy powder into the printer powder supply bin, evenly spread the powder into the printer powder spreading bin, adjust the printing parameters according to the two-dimensional slices of the three-dimensional model input by the printer, and obtain the aluminum alloy layered topological structure frame after printing; (2) Preform preparation: High entropy alloy powder is tightly and evenly filled into the aluminum alloy topological structure frame obtained in step (1) to obtain a preform, and then the preform is fixed as a whole in a cylindrical graphite groove with a suitable size and a hole, wherein the graphite groove and the preform cooperate with each other; (3) Melting aluminum alloy and preform preheating: Weighing aluminum alloy, placing it in a melting furnace for heating, melting, heat preservation, and refining to obtain aluminum alloy melt; placing the preform obtained in step (2) together with the graphite mold into a steel mold, and heating and heat preservation; (4) Preparation of layered aluminum-based composite materials: The aluminum alloy melt obtained in step (3) is cast into a steel mold using a hydraulic press, and then pressure infiltration is performed; after the aluminum alloy melt is completely infiltrated into the preform under pressure, a layered aluminum-based composite material reinforced with high entropy alloy particles is obtained after cooling and solidification.

2. The preparation process of a high entropy alloy particle reinforced layered aluminum-based composite material according to claim 1, characterized in that: In step (1), the designed layered topological structure framework includes various polygons; the polygons include triangles, quadrilaterals or hexagons, with side lengths ranging from 1mm to 10mm and thicknesses ranging from 0.1mm to 1mm.

3. The preparation process of a high entropy alloy particle reinforced layered aluminum-based composite material according to claim 1, characterized in that: In step (1), the aluminum alloy powder is mainly an Al-Si alloy suitable for selective laser melting (SLM) technology, and the aluminum alloy powder includes AlSi10Mg, AlSi12 or AlSi7Mg; The aluminum alloy powder has a particle size range of 10 to 100 μm and a purity range of 99% to 99.99%.

4. The process for preparing a high entropy alloy particle reinforced layered aluminum-based composite material according to claim 1, characterized in that: In step (1), the aluminum alloy powder is placed in a vacuum drying oven and heated to 60-100° C., and then kept dry for 2-10 hours.

5. The process for preparing a high entropy alloy particle reinforced layered aluminum-based composite material according to claim 1, characterized in that: In step (1), the printing parameters of the layered topological structure framework are: laser power of 200-400W, scanning speed of 1100-1400mm / s, scanning strategy of laser scanning direction of two adjacent layers at 60°-70°, scanning spacing of 100-150μm, and powder layer thickness of 10-100μm.

6. The process for preparing a high entropy alloy particle reinforced layered aluminum-based composite material according to claim 1, characterized in that: In step (2), the selected high entropy alloy powder comprises FeCoCrNi series, FeCoMnNi series, AlFeCoCrNi series or AlTi series; the particle size of the high entropy alloy powder ranges from 10 to 100 μm, and the purity ranges from 99% to 99.99%; The holes of the cylindrical graphite grooves are circular and have a diameter of 0.1-2 mm.

7. The process for preparing a high entropy alloy particle reinforced layered aluminum-based composite material according to claim 1, characterized in that: In step (3), the composition of the aluminum alloy is consistent with or similar to the composition of the aluminum alloy powder in step (1); the mass of the aluminum alloy is 3-10 times the mass of the preform.

8. The process for preparing a high entropy alloy particle reinforced layered aluminum-based composite material according to claim 1, characterized in that: In step (3), the aluminum alloy block is heated to 100-300°C above its melting point at a heating rate of 5-10°C / min and kept warm for 0.5-4h.

9. The process for preparing a high entropy alloy particle reinforced layered aluminum-based composite material according to claim 1, characterized in that: In step (3), the preform is heated to a temperature of 200-600° C. and kept warm for 2-4 hours.

10. The process for preparing a high entropy alloy particle reinforced layered aluminum-based composite material according to claim 1, characterized in that: In step (4), during the pressure infiltration process, the pressure is set to 40-120 MPa, the pressure holding time is set to 2-15 min, and the cooling time is set to 2-15 min.

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