Preparation method of non-uniform micro-nano SiCp hybrid reinforced aluminum-based composite material

Abstract

The invention discloses a preparation method of a non-uniform micro-nano SiCp hybrid reinforced aluminum-based composite material, and relates to a preparation method of an aluminum-based composite material. The problem that an existing silicon carbide particle reinforced aluminum matrix composite is high in strength and low in plasticity is solved. The micro-nano silicon carbide particle hybrid reinforced aluminum-based composite material prepared by the method has a non-uniform microstructure, nano silicon carbide particles are embedded into aluminum-based particles, dislocation motion is hindered, and the influence on deformation of a matrix is small, so that higher plasticity can be kept while the material strength is improved; the micron silicon carbide particles are distributed on the surfaces of the aluminum matrix particles, dislocation motion and matrix deformation are hindered, and the strength and rigidity of the material are improved. After extrusion treatment, the tensile strength of the composite material can reach 768MPa at most, the elastic modulus is 109GPa or above, and the ductility is maintained to be 13.6% or above.

Description

Technical Field

[0001] The invention relates to a method for preparing an aluminum-based composite material. Background Art

[0002] Aluminum-based composite materials have the characteristics of low density, good plasticity, excellent processing performance and small thermal expansion coefficient, while silicon carbide particles have the advantages of high hardness, good wear resistance, small thermal expansion coefficient and stable chemical properties. Aluminum-based composite materials reinforced with silicon carbide particles are widely used in aerospace, automobile manufacturing and electronic packaging due to their high specific strength, specific stiffness, excellent wear resistance and dimensional stability.

[0003] The addition of silicon carbide will increase the strength of the composite material, but the plasticity and toughness will be greatly reduced. Some scholars have replaced micron silicon carbide with nano silicon carbide particles to achieve the toughness of aluminum-based composite materials in order to maintain a high elongation. Low content of nano silicon carbide does achieve the coordination of strength and plasticity of aluminum-based composite materials, but the strengthening effect is not obvious. Increasing the content of nano silicon carbide will significantly reduce the strength and plasticity of the composite material.

[0004] Some scholars have studied micro-nano reinforced aluminum-based composite materials. They mixed silicon carbide particles of different sizes with aluminum or aluminum alloys to obtain uniformly distributed composite powders, and then prepared them through molding processes such as powder sintering, SPS, and pressureless infiltration. The heterogeneous structure composite material prepared by the method of mixing silicon carbide particles with aluminum or aluminum alloys simultaneously achieved the synergistic coordination of material strength and plasticity, but the strengthening effect was not obvious. The strength of the composite material was low, and the tensile strength did not exceed 400MPa. In addition, defects such as pores often appear in composite materials prepared by powder metallurgy and pressureless infiltration, resulting in reduced material strength; while the equipment cost of the spark plasma sintering method is high, and it is difficult to meet the needs of industrialization and mass production. Summary of the invention

[0005] The purpose of the present invention is to solve the problem of high strength and low plasticity of existing silicon carbide particle reinforced aluminum-based composite materials, and to prepare a high-strength, high-plasticity and high-modulus non-uniform structure silicon carbide particle reinforced aluminum-based composite material by a two-step ball milling-pressure infiltration method.

[0006] The preparation method of the non-uniform micro-nano SiCp hybrid reinforced aluminum-based composite material of the present invention is carried out according to the following steps:

[0007] 1. Weighing

[0008] Weigh 3% of nano silicon carbide particles, 9-12% of micron silicon carbide particles and the remainder of aluminum alloy powder as raw materials by volume; and weigh a process control agent;

[0009] The particle size of the nano silicon carbide particles in step 1 is 50 to 150 nm;

[0010] The particle size of the aluminum alloy powder in step 1 is 10 to 50 μm;

[0011] 2. High Energy Ball Milling

[0012] The nano-silicon carbide particles, aluminum alloy powder and process control agent weighed in step 1 are placed in a ball mill for high-energy mechanical ball milling, so that the nano-silicon carbide particles are embedded in the aluminum matrix through high-energy ball milling, and the process control agent can prevent cold welding of the powder during the grinding process, thereby obtaining a nano-silicon carbide-aluminum composite material powder;

[0013] 3. Low speed mixing

[0014] The micron silicon carbide particles weighed in step 1 and the nano silicon carbide-aluminum composite material powder obtained in step 2 are mixed at a low speed to make the micron silicon carbide particles evenly dispersed in the nano silicon carbide-aluminum composite material powder to obtain a micro-nano silicon carbide hybrid reinforced aluminum-based composite material powder;

[0015] 4. Pressing

[0016] The composite material powder obtained in step 4 is placed in a steel mold and pressed by a press to obtain a silicon carbide-aluminum composite material precursor;

[0017] 5. Precursor sintering

[0018] The silicon carbide-aluminum composite material precursor obtained in step 4 is placed in an atmosphere furnace, the atmosphere furnace is closed and vacuumized, and then a protective gas is filled to sinter the silicon carbide-aluminum composite material precursor under the protective atmosphere, and after sintering, the mold is taken out after the temperature of the atmosphere furnace drops to room temperature to obtain a high-density silicon carbide-aluminum composite material precursor;

[0019] The sintering temperature of the sintering process in step 5 is 600° C. and the sintering time is 4 to 6 hours;

[0020] VI. Preparation of heterogeneous micro-nano SiCp hybrid reinforced aluminum matrix composites by liquid phase method

[0021] Preheating the high-density silicon carbide-aluminum composite material precursor obtained in step 5, and weighing an aluminum alloy matrix of the same volume as the silicon carbide-aluminum composite material precursor, heating the aluminum alloy matrix to a melting temperature to obtain an aluminum alloy melt, and then infiltrating the aluminum alloy melt into the silicon carbide-aluminum composite material precursor under a protective atmosphere and mechanical pressure, and finally cooling and solidifying in air to obtain a non-uniform micro-nano silicon carbide particle hybrid reinforced aluminum-based composite ingot;

[0022] The composition of the aluminum alloy matrix is ​​the same as that of the aluminum alloy powder in step one.

[0023] Beneficial principles and beneficial effects of the present invention:

[0024] 1. The present invention adopts a two-step ball milling method and a pressure infiltration method to prepare a non-uniform micro-nano silicon carbide particle hybrid reinforced aluminum-based composite material, which has simple process, convenient operation, energy saving and environmental protection, low cost, and is suitable for large-scale industrial production.

[0025] 2. The micro-nano silicon carbide particle hybrid reinforced aluminum-based composite material prepared by the present invention has a non-uniform microstructure, wherein the nano silicon carbide particles are embedded in the interior of the aluminum matrix particles, hindering the movement of dislocations and having little effect on the deformation of the matrix, so that the material strength can be improved while maintaining a high plasticity; the micron silicon carbide particles are distributed on the surface of the aluminum matrix particles, hindering the movement of dislocations and the deformation of the matrix, and improving the strength and stiffness of the material.

[0026] 3. The present invention adds an appropriate amount of process control agent during the high-energy ball milling process, which can inhibit the occurrence of cold welding during the ball milling process and make the powder evenly dispersed; at the same time, fine nano-silicon carbide particles are generated in situ in the precursor after sintering to improve the strength of the material.

[0027] 4. The non-uniform micro-nano silicon carbide hybrid reinforced aluminum-based composite material prepared by the present invention has high density, is not easy to crack during subsequent processing, and has good comprehensive performance. After extrusion processing, the tensile strength of the composite material can reach up to 768MPa, the elastic modulus is above 109GPa, and the elongation is maintained above 13.6%.

[0028] 5. The non-uniform micro-nano silicon carbide particle hybrid reinforced aluminum-based composite material prepared by the present invention has high plastic toughness and can be subjected to large plastic deformation processing, such as rolling, extrusion, etc. After rolling, the composite material ingot can obtain a plate with a thickness of about 0.3 mm at the thinnest, and has excellent performance.

[0029] 6. The non-uniform micro-nano silicon carbide particle hybrid reinforced aluminum-based composite material prepared by the present invention has high strength, high stiffness and high plasticity, and has good comprehensive mechanical properties. It solves the problem of poor plasticity of silicon carbide particle reinforced aluminum-based composite materials and has broad application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 Schematic diagram of the non-uniform microstructure of the non-uniform micro-nano SiCp hybrid reinforced aluminum-based composite material prepared in Example 1;

[0031] Figure 2 This is a micrograph of the non-uniform micro-nano SiCp hybrid reinforced aluminum-based composite material prepared in Example 1; it can be seen that the prepared micro-nano silicon carbide particle hybrid reinforced aluminum-based composite material has a non-uniform microstructure. DETAILED DESCRIPTION

[0032] The technical solution of the present invention is not limited to the specific implementation modes listed below, but also includes any reasonable combination of the specific implementation modes.

[0033] Specific implementation method 1: The preparation method of the non-uniform micro-nano SiCp hybrid reinforced aluminum-based composite material in this implementation method is carried out according to the following steps:

[0034] 1. Weighing

[0035] Weigh 3% of nano silicon carbide particles, 9-12% of micron silicon carbide particles and the remainder of aluminum alloy powder as raw materials by volume; and weigh a process control agent;

[0036] The particle size of the nano silicon carbide particles in step 1 is 50 to 150 nm;

[0037] The particle size of the aluminum alloy powder in step 1 is 10 to 50 μm;

[0038] 2. High Energy Ball Milling

[0039] The nano-silicon carbide particles, aluminum alloy powder and process control agent weighed in step 1 are placed in a ball mill for high-energy mechanical ball milling, so that the nano-silicon carbide particles are embedded in the aluminum matrix through high-energy ball milling, and the process control agent can prevent cold welding of the powder during the grinding process, thereby obtaining a nano-silicon carbide-aluminum composite material powder;

[0040] 3. Low speed mixing

[0041] The micron silicon carbide particles weighed in step 1 and the nano silicon carbide-aluminum composite material powder obtained in step 2 are mixed at a low speed to make the micron silicon carbide particles evenly dispersed in the nano silicon carbide-aluminum composite material powder to obtain a micro-nano silicon carbide hybrid reinforced aluminum-based composite material powder;

[0042] 4. Pressing

[0043] The composite material powder obtained in step 4 is placed in a steel mold and pressed by a press to obtain a silicon carbide-aluminum composite material precursor;

[0044] 5. Precursor sintering

[0045] The silicon carbide-aluminum composite material precursor obtained in step 4 is placed in an atmosphere furnace, the atmosphere furnace is closed and vacuumized, and then a protective gas is filled to sinter the silicon carbide-aluminum composite material precursor under the protective atmosphere, and after sintering, the mold is taken out after the temperature of the atmosphere furnace drops to room temperature to obtain a high-density silicon carbide-aluminum composite material precursor;

[0046] The sintering temperature of the sintering process in step 5 is 600° C. and the sintering time is 4 to 6 hours;

[0047] VI. Preparation of heterogeneous micro-nano SiCp hybrid reinforced aluminum matrix composites by liquid phase method

[0048] Preheating the high-density silicon carbide-aluminum composite material precursor obtained in step 5, and weighing an aluminum alloy matrix of the same volume as the silicon carbide-aluminum composite material precursor, heating the aluminum alloy matrix to a melting temperature to obtain an aluminum alloy melt, and then infiltrating the aluminum alloy melt into the silicon carbide-aluminum composite material precursor under a protective atmosphere and mechanical pressure, and finally cooling and solidifying in air to obtain a non-uniform micro-nano silicon carbide particle hybrid reinforced aluminum-based composite ingot;

[0049] The composition of the aluminum alloy matrix is ​​the same as that of the aluminum alloy powder in step one.

[0050] This implementation has the following beneficial effects:

[0051] 1. This embodiment adopts a two-step ball milling method and a pressure infiltration method to prepare a non-uniform micro-nano silicon carbide particle hybrid reinforced aluminum-based composite material, which has simple process, convenient operation, energy saving and environmental protection, low cost, and is suitable for large-scale industrial production.

[0052] 2. The micro-nano silicon carbide particle hybrid reinforced aluminum-based composite material prepared in this embodiment has a non-uniform microstructure, in which the nano silicon carbide particles are embedded in the interior of the aluminum matrix particles, hindering the movement of dislocations and having little effect on the deformation of the matrix. Therefore, it is possible to maintain a high plasticity while improving the strength of the material; the micron silicon carbide particles are distributed on the surface of the aluminum matrix particles, hindering the movement of dislocations and the deformation of the matrix, thereby improving the strength and stiffness of the material.

[0053] 3. In this embodiment, an appropriate amount of process control agent is added during the high-energy ball milling process, which can inhibit the occurrence of cold welding during the ball milling process and make the powder evenly dispersed; at the same time, fine nano-silicon carbide particles are generated in situ in the precursor after sintering to improve the strength of the material.

[0054] 4. The non-uniform micro-nano silicon carbide hybrid reinforced aluminum-based composite material prepared in this embodiment has high density, is not easy to crack during subsequent processing, and has good comprehensive performance. After extrusion, the tensile strength of the composite material can reach up to 768MPa, the elastic modulus is above 109GPa, and the elongation is maintained above 13.6%.

[0055] 5. The non-uniform micro-nano silicon carbide particle hybrid reinforced aluminum-based composite material prepared in this embodiment has high plastic toughness and can be subjected to large plastic deformation processing, such as rolling, extrusion, etc. After rolling, the composite ingot can obtain a plate with a thickness of about 0.3 mm at the thinnest, and has excellent performance.

[0056] 6. The non-uniform micro-nano silicon carbide particle hybrid reinforced aluminum-based composite material prepared in this embodiment has high strength, high stiffness and high plasticity, and has good comprehensive mechanical properties. It solves the problem of poor plasticity of silicon carbide particle reinforced aluminum-based composite materials and has broad application prospects.

[0057] Specific implementation method 2: This implementation method is different from specific implementation method 1 in that: the process control agent in step 1 is polysilazane or polysilicon carbamate; the process control agent is 1 to 3% of the total mass of the nano-silicon carbide particles and the aluminum alloy powder.

[0058] Specific embodiment three: This embodiment is different from specific embodiment one or two in that the aluminum alloy powder described in step one is pure aluminum, Al-Si alloy, Al-Si-Cu alloy, Al-Mg-Si alloy, Al-Cu-Mg alloy, Al-Zn-Cu alloy, Al-Zn-Mg-Cu alloy, Al-Si-Cu-Mg alloy, or a combination of several of them.

[0059] Specific implementation method 4: This implementation method is different from any one of specific implementation methods 1 to 3 in that: the ball-to-material mass ratio of the high-energy ball milling in step 2 is 10:1, the rotation speed is 200-300 r / min; and the ball milling time is 4-6 h.

[0060] Specific implementation method five: This implementation method is different from any one of specific implementation methods one to four in that: the rotation speed of the low-speed mixing in step three is 40 to 50 r / min; the ball-to-material mass ratio is 5 to 10:1; and the mixing time is 4 to 6 hours.

[0061] Specific implementation method 6: This implementation method is different from any one of specific implementation methods 1 to 5 in that: the pressure of the pressing molding in step 4 is 60 to 70 KN; and the holding time is 10 to 20 minutes.

[0062] Specific implementation method 7: This implementation method is different from the specific implementation methods 1 to 6 in that: the vacuum pumping in step 5 is 0 to 10 -3 Pa.

[0063] Specific implementation eight: This implementation differs from any one of specific implementations one to seven in that the protective gas in step five is nitrogen, argon or helium.

[0064] Specific implementation method 9: This implementation method is different from any one of specific implementation methods 1 to 8 in that: the protective atmosphere in step 6 is an argon atmosphere.

[0065] Specific embodiment ten: This embodiment differs from any one of specific embodiments one to nine in that: the mechanical pressure applied during the infiltration in step six is ​​5 to 10 MPa.

[0066] Example 1

[0067] The preparation method of the non-uniform micro-nano SiCp hybrid reinforced aluminum-based composite material of this embodiment is carried out according to the following steps:

[0068] 1. Weighing

[0069] Weigh 3% of nano silicon carbide particles, 12% of micron silicon carbide particles and the remainder of aluminum alloy powder as raw materials by volume; and weigh a process control agent;

[0070] The particle size of the nano silicon carbide particles in step 1 is 150 nm;

[0071] The particle size of the aluminum alloy powder in step 1 is 10 μm;

[0072] The process control agent in step 1 is polysilicon carbide; the process control agent is 3% of the total mass of the nano-silicon carbide particles and the aluminum alloy powder;

[0073] The aluminum alloy powder described in step 1 is 6061 aluminum alloy;

[0074] 2. High Energy Ball Milling

[0075] The nano-silicon carbide particles, aluminum alloy powder and process control agent weighed in step 1 are placed in a ball mill for high-energy mechanical ball milling, so that the nano-silicon carbide particles are embedded in the aluminum matrix through high-energy ball milling, and the process control agent can prevent cold welding of the powder during the grinding process, thereby obtaining a nano-silicon carbide-aluminum composite material powder;

[0076] In step 2, the ball-to-material mass ratio of the high-energy ball mill is 10:1, the rotation speed is 200 r / min, and the ball milling time is 6 h;

[0077] 3. Low speed mixing

[0078] The micron silicon carbide particles weighed in step 1 and the nano silicon carbide-aluminum composite material powder obtained in step 2 are mixed at a low speed to make the micron silicon carbide particles evenly dispersed in the nano silicon carbide-aluminum composite material powder to obtain a micro-nano silicon carbide hybrid reinforced aluminum-based composite material powder;

[0079] The speed of low-speed mixing in step 3 is 50r / min; the mass ratio of ball to material is 10:1; the mixing time is 6h;

[0080] 4. Pressing

[0081] The composite material powder obtained in step 4 is placed in a steel mold and pressed by a press to obtain a silicon carbide-aluminum composite material precursor;

[0082] The pressing pressure in step 4 is 60KN; the holding time is 10min;

[0083] 5. Precursor sintering

[0084] The silicon carbide-aluminum composite material precursor obtained in step 4 is placed in an atmosphere furnace, the atmosphere furnace is closed and vacuumized, and then a protective gas is filled to sinter the silicon carbide-aluminum composite material precursor under the protective atmosphere, and after sintering, the mold is taken out after the temperature of the atmosphere furnace drops to room temperature to obtain a high-density silicon carbide-aluminum composite material precursor;

[0085] Step 5: Vacuum until the vacuum degree is 10 -3 Pa;

[0086] The sintering temperature of the sintering process in step 5 is 600° C. and the sintering time is 4 h;

[0087] The protective gas in step 5 is nitrogen;

[0088] VI. Preparation of heterogeneous micro-nano SiCp hybrid reinforced aluminum matrix composites by liquid phase method

[0089] Preheating the high-density silicon carbide-aluminum composite material precursor obtained in step 5, and weighing an aluminum alloy matrix of the same volume as the silicon carbide-aluminum composite material precursor, heating the aluminum alloy matrix to a melting temperature to obtain an aluminum alloy melt, and then infiltrating the aluminum alloy melt into the silicon carbide-aluminum composite material precursor under a protective atmosphere and mechanical pressure, and finally cooling and solidifying in air to obtain a non-uniform micro-nano silicon carbide particle hybrid reinforced aluminum-based composite ingot;

[0090] The composition of the aluminum alloy matrix is ​​the same as that of the aluminum alloy powder in step 1;

[0091] The protective atmosphere in step 6 is argon atmosphere;

[0092] The mechanical pressure applied during the infiltration in step six is ​​5 MPa.

[0093] Figure 1 Schematic diagram of the non-uniform microstructure of the non-uniform micro-nano SiCp hybrid reinforced aluminum-based composite material prepared in Example 1; wherein the nano silicon carbide particles are embedded in the interior of the aluminum matrix particles, which can hinder the movement of dislocations and have little effect on the deformation of the matrix, so that the material strength can be improved while maintaining a high plasticity; micron silicon carbide particles are distributed on the surface of the aluminum matrix particles, hindering the movement of dislocations and matrix deformation, and improving the strength and stiffness of the material. Figure 2 This is a micrograph of the non-uniform micro-nano SiCp hybrid reinforced aluminum-based composite material prepared in Example 1; it can be seen that the prepared micro-nano silicon carbide particle hybrid reinforced aluminum-based composite material has a non-uniform microstructure. The non-uniform micro-nano silicon carbide hybrid reinforced aluminum-based composite material prepared in this example has a tensile strength of 721 MPa, an elastic modulus of 118 GPa, and an elongation of 14.7%.

[0094] Example 2

[0095] The preparation method of the non-uniform micro-nano SiCp hybrid reinforced aluminum-based composite material of this embodiment is carried out according to the following steps:

[0096] 1. Weighing

[0097] Weigh 3% of nano silicon carbide particles, 12% of micron silicon carbide particles and the remainder of aluminum alloy powder as raw materials by volume; and weigh a process control agent;

[0098] The particle size of the nano silicon carbide particles in step 1 is 150 nm;

[0099] The particle size of the aluminum alloy powder in step 1 is 50 μm;

[0100] The process control agent in step 1 is polysilazane; the process control agent is 3% of the total mass of the nano-silicon carbide particles and the aluminum alloy powder;

[0101] The aluminum alloy powder described in step 1 is 6061 aluminum alloy;

[0102] 2. High Energy Ball Milling

[0103] The nano-silicon carbide particles, aluminum alloy powder and process control agent weighed in step 1 are placed in a ball mill for high-energy mechanical ball milling, so that the nano-silicon carbide particles are embedded in the aluminum matrix through high-energy ball milling, and the process control agent can prevent cold welding of the powder during the grinding process, thereby obtaining a nano-silicon carbide-aluminum composite material powder;

[0104] In step 2, the ball-to-material mass ratio of the high-energy ball mill is 10:1, the rotation speed is 200 r / min, and the ball milling time is 6 h;

[0105] 3. Low speed mixing

[0106] The micron silicon carbide particles weighed in step 1 and the nano silicon carbide-aluminum composite material powder obtained in step 2 are mixed at a low speed to make the micron silicon carbide particles evenly dispersed in the nano silicon carbide-aluminum composite material powder to obtain a micro-nano silicon carbide hybrid reinforced aluminum-based composite material powder;

[0107] The speed of low-speed mixing in step 3 is 40r / min; the mass ratio of ball to material is 10:1; the mixing time is 6h;

[0108] 4. Pressing

[0109] The composite material powder obtained in step 4 is placed in a steel mold and pressed by a press to obtain a silicon carbide-aluminum composite material precursor;

[0110] The pressing pressure in step 4 is 60KN; the holding time is 10min;

[0111] 5. Precursor sintering

[0112] The silicon carbide-aluminum composite material precursor obtained in step 4 is placed in an atmosphere furnace, the atmosphere furnace is closed and vacuumized, and then a protective gas is filled to sinter the silicon carbide-aluminum composite material precursor under the protective atmosphere, and after sintering, the mold is taken out after the temperature of the atmosphere furnace drops to room temperature to obtain a high-density silicon carbide-aluminum composite material precursor;

[0113] Step 5: Vacuum until the vacuum degree is 10 -3 Pa;

[0114] The sintering temperature of the sintering process in step 5 is 600° C. and the sintering time is 4 h;

[0115] The protective gas in step 5 is nitrogen;

[0116] VI. Preparation of heterogeneous micro-nano SiCp hybrid reinforced aluminum matrix composites by liquid phase method

[0117] Preheating the high-density silicon carbide-aluminum composite material precursor obtained in step 5, and weighing an aluminum alloy matrix of the same volume as the silicon carbide-aluminum composite material precursor, heating the aluminum alloy matrix to a melting temperature to obtain an aluminum alloy melt, and then infiltrating the aluminum alloy melt into the silicon carbide-aluminum composite material precursor under a protective atmosphere and mechanical pressure, and finally cooling and solidifying in air to obtain a non-uniform micro-nano silicon carbide particle hybrid reinforced aluminum-based composite ingot;

[0118] The composition of the aluminum alloy matrix is ​​the same as that of the aluminum alloy powder in step 1;

[0119] The protective atmosphere in step 6 is argon atmosphere;

[0120] The mechanical pressure applied during the infiltration in step six is ​​5 MPa.

[0121] The tensile strength of the non-uniform micro-nano silicon carbide hybrid reinforced aluminum-based composite material prepared in this embodiment is 689 MPa, the elastic modulus is 112 GPa, and the elongation is 14.1%.

[0122] Example 3

[0123] The preparation method of the non-uniform micro-nano SiCp hybrid reinforced aluminum-based composite material of this embodiment is carried out according to the following steps:

[0124] 1. Weighing

[0125] Weigh 3% of nano silicon carbide particles, 12% of micron silicon carbide particles and the remainder of aluminum alloy powder as raw materials by volume; and weigh a process control agent;

[0126] The particle size of the nano silicon carbide particles in step 1 is 50 nm;

[0127] The particle size of the aluminum alloy powder in step 1 is 10 μm;

[0128] The process control agent in step 1 is polysilicon carbide; the process control agent is 3% of the total mass of the nano-silicon carbide particles and the aluminum alloy powder;

[0129] The aluminum alloy powder described in step 1 is 6061 aluminum alloy;

[0130] 2. High Energy Ball Milling

[0131] The nano-silicon carbide particles, aluminum alloy powder and process control agent weighed in step 1 are placed in a ball mill for high-energy mechanical ball milling, so that the nano-silicon carbide particles are embedded in the aluminum matrix through high-energy ball milling, and the process control agent can prevent cold welding of the powder during the grinding process, thereby obtaining a nano-silicon carbide-aluminum composite material powder;

[0132] In step 2, the ball-to-material mass ratio of the high-energy ball mill is 10:1, the rotation speed is 250 r / min, and the ball milling time is 4 h;

[0133] 3. Low speed mixing

[0134] The micron silicon carbide particles weighed in step 1 and the nano silicon carbide-aluminum composite material powder obtained in step 2 are mixed at a low speed to make the micron silicon carbide particles evenly dispersed in the nano silicon carbide-aluminum composite material powder to obtain a micro-nano silicon carbide hybrid reinforced aluminum-based composite material powder;

[0135] The speed of low-speed mixing in step 3 is 40r / min; the mass ratio of ball to material is 10:1; the mixing time is 4h;

[0136] 4. Pressing

[0137] The composite material powder obtained in step 4 is placed in a steel mold and pressed by a press to obtain a silicon carbide-aluminum composite material precursor;

[0138] The pressing pressure in step 4 is 60KN; the holding time is 10min;

[0139] 5. Precursor sintering

[0140] The silicon carbide-aluminum composite material precursor obtained in step 4 is placed in an atmosphere furnace, the atmosphere furnace is closed and vacuumized, and then a protective gas is filled to sinter the silicon carbide-aluminum composite material precursor under the protective atmosphere, and after sintering, the mold is taken out after the temperature of the atmosphere furnace drops to room temperature to obtain a high-density silicon carbide-aluminum composite material precursor;

[0141] Step 5: Vacuum until the vacuum degree is 10 -3 Pa;

[0142] The sintering temperature of the sintering process in step 5 is 600° C. and the sintering time is 4 h;

[0143] The protective gas in step 5 is nitrogen;

[0144] VI. Preparation of heterogeneous micro-nano SiCp hybrid reinforced aluminum matrix composites by liquid phase method

[0145] Preheating the high-density silicon carbide-aluminum composite material precursor obtained in step 5, and weighing an aluminum alloy matrix of the same volume as the silicon carbide-aluminum composite material precursor, heating the aluminum alloy matrix to a melting temperature to obtain an aluminum alloy melt, and then infiltrating the aluminum alloy melt into the silicon carbide-aluminum composite material precursor under a protective atmosphere and mechanical pressure, and finally cooling and solidifying in air to obtain a non-uniform micro-nano silicon carbide particle hybrid reinforced aluminum-based composite ingot;

[0146] The composition of the aluminum alloy matrix is ​​the same as that of the aluminum alloy powder in step 1;

[0147] The protective atmosphere in step 6 is argon atmosphere;

[0148] The mechanical pressure applied during the infiltration in step six is ​​5 MPa.

[0149] The tensile strength of the non-uniform micro-nano silicon carbide hybrid reinforced aluminum-based composite material prepared in this embodiment is 768 MPa, the elastic modulus is 109 GPa, and the elongation is 13.6%.

Claims

1. A method for preparing a non-uniform micro-nano SiCp hybrid reinforced aluminum-based composite material, characterized in that: The preparation method of the non-uniform micro-nano SiCp hybrid reinforced aluminum matrix composite material is carried out according to the following steps:

1. Weighing Weigh 3% of nano silicon carbide particles, 9-12% of micron silicon carbide particles and the remainder of aluminum alloy powder as raw materials by volume; and weigh a process control agent; The particle size of the nano silicon carbide particles in step 1 is 50 to 150 nm; The particle size of the aluminum alloy powder in step 1 is 10 to 50 μm; 2. High Energy Ball Milling The nano-silicon carbide particles, aluminum alloy powder and process control agent weighed in step 1 are placed in a ball mill for high-energy mechanical ball milling, so that the nano-silicon carbide particles are embedded in the aluminum matrix through high-energy ball milling, and the process control agent can prevent cold welding of the powder during the grinding process, thereby obtaining a nano-silicon carbide-aluminum composite material powder; 3. Low speed mixing The micron silicon carbide particles weighed in step 1 and the nano silicon carbide-aluminum composite material powder obtained in step 2 are mixed at a low speed to make the micron silicon carbide particles evenly dispersed in the nano silicon carbide-aluminum composite material powder to obtain a micro-nano silicon carbide hybrid reinforced aluminum-based composite material powder; 4. Pressing The composite material powder obtained in step 4 is placed in a steel mold and pressed by a press to obtain a silicon carbide-aluminum composite material precursor; 5. Precursor sintering The silicon carbide-aluminum composite material precursor obtained in step 4 is placed in an atmosphere furnace, the atmosphere furnace is closed and vacuumized, and then a protective gas is filled to sinter the silicon carbide-aluminum composite material precursor under the protective atmosphere, and after sintering, the mold is taken out after the temperature of the atmosphere furnace drops to room temperature to obtain a high-density silicon carbide-aluminum composite material precursor; The sintering temperature of the sintering process in step 5 is 600° C. and the sintering time is 4 to 6 hours; VI. Preparation of heterogeneous micro-nano SiCp hybrid reinforced aluminum matrix composites by liquid phase method Preheating the high-density silicon carbide-aluminum composite material precursor obtained in step 5, and weighing an aluminum alloy matrix of the same volume as the silicon carbide-aluminum composite material precursor, heating the aluminum alloy matrix to a melting temperature to obtain an aluminum alloy melt, and then infiltrating the aluminum alloy melt into the silicon carbide-aluminum composite material precursor under a protective atmosphere and mechanical pressure, and finally cooling and solidifying in air to obtain a non-uniform micro-nano silicon carbide particle hybrid reinforced aluminum-based composite ingot; The composition of the aluminum alloy matrix is ​​the same as that of the aluminum alloy powder in step one.

2. The method for preparing the non-uniform micro-nano SiCp hybrid reinforced aluminum-based composite material according to claim 1, characterized in that: The process control agent described in step 1 is polysilazane or polysilicon carbane; the process control agent is 1 to 3% of the total mass of the nano-silicon carbide particles and the aluminum alloy powder.

3. The method for preparing the non-uniform micro-nano SiCp hybrid reinforced aluminum-based composite material according to claim 1, characterized in that: The aluminum alloy powder described in step 1 is one of pure aluminum, Al-Si alloy, Al-Si-Cu alloy, Al-Mg-Si alloy, Al-Cu-Mg alloy, Al-Zn-Cu alloy, Al-Zn-Mg-Cu alloy, Al-Si-Cu-Mg alloy, or a combination of several thereof.

4. The method for preparing the non-uniform micro-nano SiCp hybrid reinforced aluminum-based composite material according to claim 1, characterized in that: In step 2, the ball-to-material mass ratio of the high-energy ball mill is 10:1, the rotation speed is 200-300 r / min, and the ball milling time is 4-6 h.

5. The method for preparing the non-uniform micro-nano SiCp hybrid reinforced aluminum-based composite material according to claim 1, characterized in that: The rotation speed of the low-speed mixing in step 3 is 40-50 r / min; the mass ratio of the balls to the materials is 5-10:1; and the mixing time is 4-6 hours.

6. The method for preparing the non-uniform micro-nano SiCp hybrid reinforced aluminum-based composite material according to claim 1, characterized in that: The pressing pressure in step 4 is 60-70 KN; the holding time is 10-20 min.

7. The method for preparing the non-uniform micro-nano SiCp hybrid reinforced aluminum-based composite material according to claim 1, characterized in that: Step 5: Vacuum until the vacuum degree is 0-10 -3 Pa.

8. The method for preparing the non-uniform micro-nano SiCp hybrid reinforced aluminum-based composite material according to claim 1, characterized in that: The protective gas in step five is nitrogen, argon or helium.

9. The method for preparing the non-uniform micro-nano SiCp hybrid reinforced aluminum-based composite material according to claim 1, characterized in that: The protective atmosphere in step six is ​​argon atmosphere.

10. The method for preparing the non-uniform micro-nano SiCp hybrid reinforced aluminum-based composite material according to claim 1, characterized in that: The mechanical pressure applied during the infiltration in step 6 is 5 to 10 MPa.

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