Multi-pass pressure sintering-based low-cost high-quality preparation method of aluminum-based composite material containing multiple reinforcements

Abstract

The invention relates to a multi-pass pressure sintering-based high-quality preparation method of a low-cost multi-reinforcement-containing aluminum-based composite material, in particular to a multi-pass pressure sintering-based high-quality preparation method of a low-cost multi-reinforcement-containing aluminum-based composite material. The method aims at solving the problems that in the powder metallurgy preparation process of the aluminum-based composite material, the density is low, the mechanical property is poor, and interfaces between reinforcement bodies with different properties and a base body are not matched. The method comprises the following steps: 1, weighing a reinforcement material and an aluminum-containing material; 2, uniformly mixing the powder through a mechanical ball milling method or a V-shaped mixer; 3, the mixed powder is put into a mold; 4, performing cold pressing to prepare a prefabricated body; 5, multi-pass hot pressed sintering; and 6, demolding. The aluminum-based composite material is prepared at low equipment cost, and is high in density, excellent in mechanical property and good in hot working property. The aluminum-based composite material can be applied in various scenes through the matching of different types of reinforcements with different volume fractions and the aluminum-containing material.

Description

Technical Field

[0001] This invention relates to a low-cost, high-quality preparation method for aluminum matrix composites containing multiple reinforcements based on multi-pass pressure sintering. Background Technology

[0002] In the field of aluminum matrix composites, the differences in properties and chemical reactions between the reinforcement and the matrix are the core factors determining the preparation results. Because the reinforcement and the aluminum matrix often differ significantly in key properties such as melting point and coefficient of thermal expansion, poor interfacial bonding can easily occur, leading to problems such as decreased mechanical properties and insufficient structural stability in the composite material. This is especially true when multiple reinforcements with significantly different properties are introduced, as the interfacial matching contradictions between different reinforcements and the matrix become more pronounced, severely restricting the functional integration and performance optimization of the composite material.

[0003] Powder metallurgy, as an important technique for preparing aluminum-based composites, leverages its advantage of lower preparation temperatures to effectively suppress the intense chemical reactions between the reinforcement and the matrix at high temperatures, providing a means to control interfacial reactions and improve material properties. Simultaneously, this method supports the multifunctional design of composites by adding different types of reinforcements to meet performance requirements in various scenarios. However, traditional powder metallurgy processes still face many challenges in practical applications: on the one hand, sintering processes with single or fixed parameters struggle to balance the interfacial compatibility between multiple reinforcements and the matrix, resulting in generally low composite density and poor mechanical properties (such as strength and plasticity); on the other hand, loading pressure and holding temperature, as key process parameters in powder metallurgy, directly affect the density, microstructure, and final mechanical properties of the material. Traditional processes lack sufficient precision and flexibility in controlling these parameters, making it difficult to achieve stable preparation of high-density, high-performance composites.

[0004] Furthermore, existing high-performance powder metallurgy equipment (such as vacuum hot pressing furnaces and spark plasma sintering equipment) is expensive and complex to operate, hindering large-scale production and low-cost applications. Therefore, optimizing powder metallurgy process parameters (such as temperature and pressure) to reduce equipment costs while addressing the issues of low density, poor mechanical properties, and interface mismatch between multiple reinforcements and the matrix in aluminum matrix composites has become a key technological bottleneck for promoting the high-quality, low-cost preparation of aluminum matrix composites. This invention addresses this technological challenge by proposing a low-cost preparation method based on multi-pass pressure sintering, aiming to achieve high-quality preparation of aluminum matrix composites containing multiple reinforcements through precise process control. Summary of the Invention

[0005] The present invention aims to address the problems of low density, poor mechanical properties, and interface mismatch between reinforcing agents with different properties and the matrix in the powder metallurgy preparation process of aluminum matrix composites, and provides a low-cost, high-quality preparation method of aluminum matrix composites containing multiple reinforcing agents based on multi-pass pressure sintering.

[0006] The present invention discloses a low-cost, high-quality preparation method for aluminum matrix composites containing multiple reinforcements based on multi-pass pressure sintering, which is carried out according to the following steps:

[0007] 1. Weigh out 5%-50% of the reinforcing material and 50%-95% of the aluminum-containing material as raw materials according to volume fraction;

[0008] 2. The reinforcing material and aluminum-containing material weighed in step 1 are ball-milled to obtain a mixed powder;

[0009] 3. Dry the mixed powder obtained in step 2 to obtain dried mixed powder;

[0010] 4. Load the dried mixed powder obtained in step 3 into a steel mold, apply a specified pressure and hold the pressure for a certain time to obtain a preform;

[0011] 5. The preform obtained in step 4 is first kept at a set temperature, then a specified pressure is applied and held for a certain time, and then the pressure is released after completion.

[0012] 6. Repeat the heat preservation and pressurization process in step 5 1-5 times to obtain the composite material;

[0013] 7. The composite material obtained in step 6 is first heat-preserved at a set temperature, then a specified pressure is applied and held for a certain time. After completion, the pressure is released and the aluminum-based composite material is demolded.

[0014] The beneficial effects of this invention are:

[0015] This invention employs a low-cost, multi-pass pressure sintering method for preparing high-quality aluminum matrix composites containing various reinforcements. Through a low-equipment-cost, multi-pass pressure powder metallurgy process, high-density aluminum matrix composites with excellent mechanical properties and good hot workability are prepared. The aluminum matrix composites prepared by this invention can achieve interface matching between reinforcements and the matrix with significantly different properties; their density and overall mechanical properties are superior to other powder metallurgy methods; the equipment cost is far lower than other powder metallurgy equipment such as vacuum hot pressing furnaces and spark plasma sintering; the preparation process is simple, controllable, and easy for mass production; a wide variety of reinforcement and matrix materials can be selected, with a broad volume fraction distribution range, allowing for the acquisition of aluminum matrix composites with multiple components to meet different performance requirements; the size of the prepared materials is not limited, and it can be used for the preparation of large-size aluminum matrix composites. This invention provides a low-cost, multi-pass sintering method for preparing high-quality aluminum-based composite materials containing various reinforcements. This method can reduce equipment costs while producing high-density aluminum-based composite materials with excellent mechanical and thermal processing properties. The preparation process is simple and controllable, and the ratio of different types and volume fractions of reinforcements to aluminum-containing materials can achieve the integration of structure and function in aluminum-based composite materials. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of a low-cost, high-quality preparation method for aluminum matrix composites containing multiple reinforcements based on multi-pass pressure sintering;

[0017] Figure 2 This is a comparison of the tensile properties of a low-cost, high-quality aluminum matrix composite material with multiple reinforcements based on multi-pass pressure sintering with other existing preparation methods under the same process conditions.

[0018] Figure 3 The image shows the macroscopic morphology of the aluminum-based composite material containing multiple reinforcing agents prepared in Example 1. Detailed Implementation

[0019] Specific Implementation Method 1: This implementation method describes a low-cost, high-quality preparation method for aluminum matrix composites containing multiple reinforcements based on multi-pass pressure sintering, which is carried out according to the following steps:

[0020] 1. Weigh out 5%-50% of the reinforcing material and 50%-95% of the aluminum-containing material as raw materials according to volume fraction;

[0021] 2. The reinforcing material and aluminum-containing material weighed in step 1 are ball-milled to obtain a mixed powder;

[0022] 3. Dry the mixed powder obtained in step 2 to obtain dried mixed powder;

[0023] 4. Load the dried mixed powder obtained in step 3 into a steel mold, apply a specified pressure and hold the pressure for a certain time to obtain a preform;

[0024] 5. The preform obtained in step 4 is first kept at a set temperature, then a specified pressure is applied and held for a certain time, and then the pressure is released after completion.

[0025] 6. Repeat the heat preservation and pressurization process in step 5 1-5 times to obtain the composite material;

[0026] 7. The composite material obtained in step 6 is first heat-preserved at a set temperature, then a specified pressure is applied and held for a certain time. After completion, the pressure is released and the aluminum-based composite material is demolded.

[0027] This embodiment achieves stepwise control of the interfacial reaction through multiple heat preservation-pressurization cycles. In the first heat preservation stage, the aluminum matrix is ​​in a semi-solid or softened state, and a thin oxide layer or diffusion layer is initially formed on the surface of the reinforcement, laying the foundation for interfacial bonding. Each subsequent pressurization promotes close contact between the matrix and the reinforcement, reduces interfacial porosity, and alleviates residual interfacial stress caused by differences in thermal expansion through dynamic stress release. Finally, high-temperature heat preservation promotes interfacial atomic diffusion, forming a stable transition phase, avoiding excessive formation of brittle phases, and achieving interfacial matching between multiple reinforcements and the matrix.

[0028] This embodiment employs stepwise low-pressure loading of 10-100 MPa, which avoids interfacial damage caused by reinforcement breakage or uneven plastic flow of the matrix under high stress. For reinforcements with significantly different properties (such as brittle ceramic phase boron carbide and ductile metallic phase tungsten), the stepped pressure can be adapted to their interfacial bonding requirements, reducing the risk of interfacial cracking.

[0029] This implementation achieves high density through a three-stage densification process: "pre-compression molding - multi-pass sintering and pressurization - final-state heat preservation and pressurization". Initial pressure eliminates macroscopic pores between powder particles, forming a uniformly structured green body, laying the foundation for densification in subsequent sintering. Each heat preservation in the multi-pass cyclic pressurization process enhances the diffusion ability of powder atoms, and subsequent pressurization can further eliminate micropores generated by diffusion, forming a cyclic strengthening effect of "diffusion-densification". The long-term heat preservation and pressurization in the final state completely eliminates residual pores through grain boundary migration and plastic flow.

[0030] Specific Implementation Method Two: This implementation method differs from Specific Implementation Method One in that: the aluminum-containing material in step one is pure aluminum, 1xxx series aluminum alloy, 2xxx series aluminum alloy, 3xxx series aluminum alloy, 4xxx series aluminum alloy, 5xxx series aluminum alloy, 6xxx series aluminum alloy, or 7xxx series aluminum alloy; the reinforcing material is one or a mixture of several of boron carbide, silicon carbide, tungsten carbide, tungsten monoboride, tungsten diboride, tungsten, boron, tantalum, boron nitride, aluminum nitride, and aluminum oxide. Everything else is the same as in Specific Implementation Method One.

[0031] Specific Implementation Method Three: This implementation method differs from Specific Implementation Method One in that the ball milling in step one uses a V-type mixer or a ball mill. Everything else is the same as in Specific Implementation Method One.

[0032] Specific Implementation Method Four: This implementation method differs from Specific Implementation Method Three in that the V-type mixer rotates at a speed of 10-30 r / min and operates for 6-24 hours. Everything else is the same as in Specific Implementation Method Three.

[0033] Specific Implementation Method Five: This implementation method differs from Specific Implementation Method Three in that the ball mill speed is 100-300 r / min, the ball-to-material ratio is (1-5):1, and the working time is 1-8 hours. Everything else is the same as in Specific Implementation Method Three.

[0034] Specific Implementation Method Six: This implementation method differs from Specific Implementation Method One in that, in step one, 15% tungsten, 15% boron carbide, and 70% aluminum-containing materials are weighed out according to volume fractions as raw materials. Everything else is the same as in Specific Implementation Method One.

[0035] Specific Implementation Method Seven: This implementation method differs from Specific Implementation Method One in that the drying in step three is carried out at a temperature of 60-120℃ for 4-8 hours. Everything else is the same as in Specific Implementation Method One.

[0036] Specific Implementation Method Eight: This implementation method differs from Specific Implementation Method One in that the loading pressure in step four is 10~200MPa and the holding time is 3~10min. Everything else is the same as in Specific Implementation Method One.

[0037] Specific Implementation Method Nine: This implementation method differs from Specific Implementation Method One in that step five is performed under an air or argon atmosphere. Everything else is the same as in Specific Implementation Method One.

[0038] Specific Implementation Method Ten: This implementation method differs from Specific Implementation Method One in that: in step five, the heat preservation temperature is 400-640℃, and the heat preservation time is 1-3 hours; the loading pressure is 10-100MPa, and the pressure holding time is 5-15 minutes. Everything else is the same as in Specific Implementation Method One.

[0039] Specific Implementation Method Eleven: This implementation method differs from Specific Implementation Method One in that: in step seven, the heat preservation temperature is 500-640℃, the heat preservation time is 1-10 hours; the loading pressure is 10-100 MPa, and the pressure holding time is 10-30 minutes. Everything else is the same as in Specific Implementation Method One.

[0040] Specific Implementation Method Twelve: This implementation method differs from Specific Implementation Method One in that the heat preservation temperature in step seven is 570-630℃, and the heat preservation time is 2-6 hours. Everything else is the same as in Specific Implementation Method One.

[0041] The beneficial effects of the present invention are verified using the following embodiments:

[0042] Example 1: A low-cost, high-quality preparation method for aluminum matrix composites containing multiple reinforcements based on multi-pass pressure sintering is carried out according to the following steps:

[0043] 1. Weigh out 15% tungsten, 15% boron carbide and 70% aluminum-containing materials by volume as raw materials;

[0044] 2. The reinforcing material and aluminum-containing material weighed in step 1 are ball-milled to obtain a mixed powder; the ball mill speed is 100-300 r / min, the ball-to-material ratio is (1-5):1, and the working time is 1-8 h.

[0045] 3. Dry the mixed powder obtained in step 2 at a temperature of 60-120℃ for 4-8 hours to obtain dried mixed powder;

[0046] 4. Load the dried mixed powder obtained in step 3 into a steel mold and hold it under pressure of 10~200MPa for 3~10min to obtain the preform;

[0047] 5. The preform obtained in step 4 is first kept at a temperature of 500-640℃ for 1-3 hours, and then pressured at a pressure of 10-100MPa for 5-15 minutes. After completion, the pressure is released.

[0048] 6. Repeat the heat preservation and pressurization process in step 5 three times to obtain the composite material;

[0049] 7. The composite material obtained in step 6 is first kept at a temperature of 550-640℃ for 1-10 hours, and then kept under a pressure of 10-100MPa for 10-30 minutes. After completion, the pressure is released and the aluminum-based composite material is demolded.

[0050] The low-cost, multi-pass sintering process obtained in Example 1 yielded a high-quality aluminum-based composite material containing multiple reinforcements with a density of 99.6%. Mechanical property testing revealed a tensile strength of 450 MPa and a flexural strength of 800 MPa, demonstrating excellent mechanical properties. Compared to the same composite material prepared by vacuum hot pressing furnace and spark plasma sintering furnace, it exhibited better plasticity, which is attributed to the superior preparation method that improved the material's density.

Claims

1. A low-cost, high-quality preparation method for aluminum matrix composites containing multiple reinforcements based on multi-pass pressure sintering, characterized in that... This method is performed according to the following steps:

1. Weigh out 5%-50% of the reinforcing material and 50%-95% of the aluminum-containing material as raw materials according to volume fraction; 2. The reinforcing material and aluminum-containing material weighed in step 1 are ball-milled to obtain a mixed powder; 3. Dry the mixed powder obtained in step 2 to obtain dried mixed powder; 4. Load the dried mixed powder obtained in step 3 into a steel mold, apply a specified pressure and hold the pressure for a certain time to obtain a preform; 5. The preform obtained in step 4 is first kept at a set temperature, then a specified pressure is applied and held for a certain time, and then the pressure is released after completion.

6. Repeat the heat preservation and pressurization process in step 5 1-5 times to obtain the composite material; 7. The composite material obtained in step 6 is first heat-preserved at a set temperature, then a specified pressure is applied and held for a certain time. After completion, the pressure is released and the aluminum-based composite material is demolded.

2. The method for preparing high-quality aluminum matrix composites containing multiple reinforcements based on multi-pass pressure sintering according to claim 1, characterized in that... The aluminum-containing material mentioned in step one is pure aluminum, 1xxx series aluminum alloy, 2xxx series aluminum alloy, 3xxx series aluminum alloy, 4xxx series aluminum alloy, 5xxx series aluminum alloy, 6xxx series aluminum alloy, or 7xxx series aluminum alloy; the reinforcing material is one or a mixture of several of boron carbide, silicon carbide, tungsten carbide, tungsten monoboride, tungsten diboride, tungsten, boron, tantalum, boron nitride, aluminum nitride, and aluminum oxide.

3. The method for preparing high-quality aluminum matrix composites containing multiple reinforcements based on multi-pass pressure sintering according to claim 1, characterized in that... The ball milling described in step one uses a V-type mixer or a ball mill.

4. The method for preparing high-quality aluminum matrix composites containing multiple reinforcements based on multi-pass pressure sintering according to claim 3, characterized in that... The V-type mixer operates at a speed of 10-30 r / min and has a working time of 6-24 hours.

5. The method for preparing high-quality aluminum matrix composites containing multiple reinforcements based on multi-pass pressure sintering according to claim 3, characterized in that... The ball mill operates at a speed of 100-300 r / min, with a ball-to-material ratio of (1-5):1, and a working time of 1-8 h.

6. The method for preparing high-quality aluminum matrix composites containing multiple reinforcements based on multi-pass pressure sintering according to claim 1, characterized in that... The drying process described in step three involves drying at a temperature of 60-120℃ for 4-8 hours.

7. The method for preparing high-quality aluminum matrix composites containing multiple reinforcements based on multi-pass pressure sintering according to claim 1, characterized in that... In step four, the loading pressure is 10~200MPa and the holding time is 3~10min.

8. The method for preparing high-quality aluminum matrix composites containing multiple reinforcements based on multi-pass pressure sintering according to claim 1, characterized in that... Step five is performed in an air or argon atmosphere.

9. A method for preparing high-quality aluminum matrix composites containing multiple reinforcements based on multi-pass pressure sintering according to claim 1, characterized in that... In step five, the heat preservation temperature is 400-640℃, and the heat preservation time is 1-3 hours; the loading pressure is 10-100MPa, and the pressure holding time is 5-15 minutes.

10. A method for preparing high-quality aluminum matrix composites containing multiple reinforcements at low cost based on multi-pass pressure sintering according to claim 1, characterized in that... In step seven, the heat preservation temperature is 500-640℃ and the heat preservation time is 1-10h; the loading pressure is 10-100MPa and the pressure holding time is 10-30min.

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