WO2020135582A1

WO2020135582A1 - Aerogel-reinforced metal matrix composite material, preparation method and application thereof

Info

Publication number: WO2020135582A1
Application number: PCT/CN2019/128689
Authority: WO
Inventors: 李光武; 王朝辉; 王强松; 杨书瑜; 胡保军
Original assignee: 北京弘微纳金科技有限公司
Priority date: 2018-12-26
Filing date: 2019-12-26
Publication date: 2020-07-02
Also published as: KR20210095937A; JP2022515532A

Abstract

Disclosed is an aerogel-reinforced metal matrix composite material, a preparation method and an application thereof. The preparation method of the composite material comprises obtaining an aerogel; obtaining a metal as a material matrix; and mixing the aerogel with the metal to react the same. The aerogel comprises silicon oxide, aluminum oxide, titanium oxide or zirconium oxide, and silicon carbide. The aerogel-reinforced metal matrix composite material and the preparation method thereof were thoroughly studied, and a series of aerogel loaded with various metal materials were obtained. These materials have better properties and performance than the original metal materials, and can satisfy various needs in the automotive, aerospace, and power electronics fields, amongst others.

Description

Aerogel reinforced metal matrix composite material and its preparation method and application

Technical field

The invention belongs to the technical field of metal materials and their preparation, and in particular relates to aerogel-reinforced metal-based composite materials and their preparation methods and applications.

Background technique

Due to its good electrical conductivity, thermal conductivity, corrosion resistance and wear resistance, copper alloys are used as conductive and thermally conductive parts, brakes and braking devices for construction machinery in many fields such as integrated circuits, transportation, aerospace, aviation, and ships. Research on copper-based composite materials used at high temperatures at home and abroad has a long history, and industrial series products such as copper-based composite oxides, carbides, borides and nitrides have been formed.

With the development of equipment to high speed and heavy load, higher requirements are placed on the wear resistance and heat resistance of copper-based friction materials. The research results of copper-based composite materials show that copper-based nano-composites prepared by using nano-scale oxides such as nano-Al ₂ O ₃ and nano-ZrO ₂ as dispersion-enhancing phases use particle reinforcement technology to form dispersions in soft and tough Cu matrix Distributed hard points to improve the strength and wear resistance of the material, while maintaining the high thermal conductivity of copper itself, improving the high-temperature softening resistance, and achieving the comprehensive improvement of electrical conductivity and strength and wear resistance, which is unmatched by other strengthening methods advantage. Therefore, the application of nano-oxide materials to copper-based wear-resistant materials provides a new way to improve the tribological properties of wear-resistant materials.

According to domestic and foreign data, the most researched at present is the Cu/Al ₂ O ₃ composite material. Nano-SiO ₂ (n-SiO ₂ ), due to its special structure and light weight, wear resistance, high temperature resistance, corrosion resistance and small coefficient of thermal expansion, although its thermal conductivity and electrical conductivity have decreased, it still remains high Level, and its price is only half of nano Al ₂ O ₃ . However, because n-SiO _{2 is} very easy to agglomerate and is not easily dispersed uniformly in the copper matrix, the performance of the prepared SiO ₂ reinforced copper matrix composite material has no advantage compared with the Cu/Al ₂ O ₃ composite material. It is rare that SiO _{2 is} used as a reinforcing phase in copper substrates.

In recent years, copper-based composite materials have been increasingly used in various fields as wear-resistant parts. Therefore, a copper-based silica composite material with high strength, high wear resistance and low cost used in high temperature environments has been developed and applied to brake parts for high temperature environments in the aerospace, automotive and other fields Manufacturing is of great significance to improving product quality and equipment service life.

With the rapid development of my country's national economy, in the fields of automobiles, aerospace, power electronics, etc., the demand for lightweight high-strength structural materials, conductive and thermally conductive materials is increasing. Aluminum alloy has the advantages of low density, high specific strength, good electrical and thermal conductivity, etc. It has broad applications in lightweight structural materials, wires and cables, heat sinks and other fields. However, there are some deficiencies in the application of aluminum materials. For example, the strength of aluminum materials is insufficient. Although traditional steel-core aluminum strands ensure the strength of cables, they also have heavy weight and large energy consumption, which is not conducive to energy saving and emission reduction.

Through alloy component design, processing methods and subsequent heat treatment technology, the performance of the alloy can be reasonably controlled. In general, by adding alloy elements, the strength of the aluminum alloy will be increased while the conductivity of the alloy will be significantly reduced, and the strength and conductivity of the alloy cannot be considered at the same time, thereby increasing the energy loss during power transmission. For example, the patent CN108559886A controls the process parameters in the production process of aluminum alloy bars, and then through subsequent online standing wave quenching, while improving the strength and electrical conductivity of the extruded bars. However, its preparation process is complicated, and its conductivity is not greatly improved, and the conductivity of the bar is lower than 50% IACS. Another example is the patent CN108546850A which uses melt casting and hot rolling processes to prepare aluminum alloy sheets with high electrical conductivity, and has the advantages of short production process and high efficiency, but its mechanical properties are poor, and the strength and electrical conductivity of the alloy are not taken into account at the same time. There are also patents such as CN103952605B, CN108570634A, CN102758107A, etc.

By adding SiC, AlN, SiO ₂ and other micro-, sub-micron or nano-scale reinforcing phase particles to the aluminum alloy, the mechanical properties of the alloy can be significantly improved, while its electrical conductivity can be maintained at a high level. For example, the invention patent CN101956113B provides a method for preparing aerospace structural materials. It adopts cubic system α-silicon carbide SiCp as a reinforcement material, and prepares Al-Bi by atomizing powder, high-energy ball milling + vacuum hot pressing. The composite material of the matrix fully utilizes the advantages of enhanced phase conductivity, good thermal conductivity, and small coefficient of thermal expansion. At the same time, it effectively improves the strength and conductivity of the matrix, so that the mechanical properties and electrical properties of the aluminum alloy are well matched. Such invention patents also include CN103526253B, CN104451475B, CN105734322B, CN106244893B, CN108677052A and so on.

Compared with the reinforced phase particles used in the above aluminum alloys, aerogel materials have excellent properties such as extremely low density, high strength, high temperature resistance, small thermal expansion coefficient, and corrosion resistance due to their special micro-nano cavity structure. The aluminum matrix composite material prepared by adding aerogel materials to aluminum and aluminum alloy materials not only has the characteristics of low density and high strength, but also has good thermal and thermal conductivity characteristics, which meets the fields of automobiles, aerospace, power electronics, etc. Application requirements for high-performance lightweight aluminum materials.

Although pure copper has good electrical and thermal conductivity, it has low strength, poor wear resistance, and is easy to soften and deform at high temperatures, which limits its application in many occasions. Through a certain process, the second phase particles with high melting point, wear resistance and corrosion resistance are added to the copper matrix to prepare the composite material, which not only maintains the excellent electrical and thermal conductivity of copper itself, but also improves the mechanical properties of the alloy And resistance to friction and wear.

The so-called second-phase particle-reinforced copper-based composite material is to disperse the required second-phase particles evenly in the copper matrix, so that the overall performance of the copper-based composite material is improved. Moreover, the second phase particles only occupy a very small volume fraction of the matrix, and therefore do not affect the inherent physical and chemical properties of the copper matrix, so the electrical conductivity and thermal conductivity of the material are not significantly reduced. The mechanical properties, electrical and thermal conductivity of the second-phase particles reinforced copper-based composite material mainly depend on the properties of the copper matrix and the second-phase particles, and the interface relationship between the second-phase particles and the matrix. Because the manufacturing cost of the second-phase particle-reinforced copper-based composite material is relatively low, isotropic, and excellent comprehensive performance, etc., it has become a research hotspot of current copper-based composite materials. Now the second-phase particle-reinforced copper alloy composite oxides, carbides, borides, nitrides and other industrialized products have been widely used in aviation, aerospace, electronics, and power fields.

Aerogel is a low-density, high-porosity material that floats in air, and its thermal conductivity can be as low as 0.012W/(m·k), which is currently recognized as the lowest thermal conductivity solid material. There are many types of aerogels, and the most widely studied and applied at present is silica aerogels. Silica aerogel is called "blue smoke", it is the lightest solid in the world at present, it is a light-weight structure with controllable structure composed of colloidal particles or polymer molecules cross-linked with each other, which has a spatial network structure. Massive nanoporous amorphous solid material, its density range is 0.003～0.2g/cm3, specific surface area is up to 800m2/g, porosity is 80～99.8%, and it has extremely low thermal conductivity, in thermal insulation, light guide , Dielectric, catalysis and other fields have broad application prospects. In view of the above characteristics of silica aerogel, adding micron-sized granular silica aerogel as a reinforcing phase to the copper matrix can obtain a composite material with special properties. At present, there is no report about the preparation process of silica aerogel supported copper composite materials.

Industrial pure aluminum has good electrical and thermal conductivity, but its strength and hardness are low, which severely limits its use. And through a certain process, the composite material prepared by adding high-melting, wear-resistant and corrosion-resistant second-phase particles (such as aluminum, magnesium, zinc, manganese, silicon and other elements) to pure aluminum not only keeps the aluminum itself excellent The strength, hardness and other properties also significantly reduce the electrical and thermal conductivity of aluminum alloys.

Add the second phase particles to pure aluminum or aluminum alloy, and obtain aluminum matrix composite material by dispersion strengthening. The so-called second phase particle reinforced aluminum matrix composite material is to disperse the required second phase particles evenly in aluminum. In the matrix, the overall performance of the aluminum matrix composite material is improved. Moreover, the second-phase particles only occupy a very small volume fraction of the aluminum matrix, and therefore do not affect the inherent physical and chemical properties of the aluminum matrix, so the electrical conductivity and thermal conductivity of the material are not significantly reduced. The mechanical properties, electrical and thermal conductivity of the second-phase particles reinforced aluminum-based composite material mainly depend on the properties of the aluminum matrix and the second-phase particles, and the interface relationship between the second-phase particles and the matrix. Because the manufacturing cost of the second phase particle reinforced aluminum matrix composites is relatively low, isotropic, and excellent comprehensive performance, etc., it has become a research hotspot of aluminum matrix composites. Now the second-phase particles reinforced aluminum alloy composite oxide, carbide, boride and nitride and other industrial series products have been widely used in aviation, aerospace, electronics and power fields.

Aerogel is a low-density, high-porosity material with a thermal conductivity of at least 0.012W/(m·k), which is currently recognized as the solid material with the lowest thermal conductivity. There are many types of aerogels. The silicon carbide aerogels currently under study and application are currently one of the lightest solids in the world. It is a controllable structure consisting of colloidal particles or polymer molecules cross-linked with each other. Lightweight nanoporous amorphous solid material with spatial network structure, silicon carbide nanowires in silicon carbide aerogel not only have high temperature resistance, oxidation resistance, corrosion resistance, high strength, high modulus, high hardness, etc. of bulk materials Excellent performance, and because of its special shape, it has super mechanical properties, excellent field emission performance, special photoluminescence performance, photocatalytic performance, etc., in the fields of thermal insulation, light guide, dielectric, catalysis, etc. have a broad vision of application. In view of the above characteristics of silicon carbide aerogel, adding micron-sized granular silicon carbide aerogel as the reinforcing phase into the aluminum matrix can obtain a composite material with special properties. At present, there is no report about the preparation process of silicon carbide aerogel reinforced aluminum matrix composites.

Industrial pure aluminum has good electrical and thermal conductivity, but its strength and hardness are low, which severely limits its use. Adding copper, magnesium, zinc, manganese, silicon and other elements to pure aluminum can effectively improve the strength and hardness of the alloy. Various grades of aluminum alloys are obtained, but at the same time, the aluminum alloy's electrical and thermal conductivity is also significantly reduced. Performance, for example, 7 series high-strength aluminum alloy has an electrical conductivity of only 30-40% IACS, only about 50% of the electrical conductivity of pure aluminum.

With the rapid development of 3C, power electronics, aerospace and other high-tech industries, especially the development of the microelectronics industry, the demand for lightweight, high thermal conductivity and high conductivity materials is increasingly urgent, with low density, high strength and high conductivity The aluminum-based materials have broad application prospects.

Traditional high-strength and high-conductivity aluminum alloy materials are realized by adding alloy elements, composition design, heat treatment, plastic processing and other technologies. Although the strength and conductivity of aluminum alloys can be improved by means of solid solution strengthening and grain boundary strengthening, the increase is limited. Although work hardening can significantly increase the strength of aluminum alloy materials, it has a significant effect on its electrical conductivity. In summary, the above method will significantly reduce the electrical conductivity of the alloy while increasing the strength of the aluminum alloy, and it is difficult to balance the strength and electrical conductivity of the alloy at the same time. For example, the patent CN108559886A controls the process parameters in the production process of aluminum alloy bars, and then through the subsequent online standing wave quenching, while improving the strength and electrical conductivity of the extruded bars. However, its preparation process is complicated, and its conductivity is not greatly improved, and the conductivity of the bar is lower than 50% IACS.

Adding hard particles to pure aluminum or aluminum alloy to obtain aluminum-based composite materials through dispersion strengthening can improve the strength of aluminum materials while ensuring that its electrical and thermal conductivity does not significantly decrease. Ceramic particles such as SiC and AlN have been used in related aluminum-based composite materials. For example, the invention patent CN101956113B provides a method for preparing SiC particle-reinforced aluminum-based composite materials. The composite material based on Al-Bi is prepared by atomizing powder, high-energy ball milling + vacuum hot pressing, so that the mechanics of aluminum alloy The performance and electrical performance are well matched, but there are shortcomings such as complicated preparation process.

It is worth noting that when the high-strength and high-conductivity aluminum matrix composites are obtained by dispersion strengthening, the properties of the second phase as dispersion strengthening will significantly affect the performance of the aluminum matrix composites finally obtained. Compared with traditional reinforced phase particles, aerogel materials such as silicon oxide, aluminum oxide, zirconium oxide, and titanium oxide have a special micro-nano cavity structure, with extremely low density, high strength, high temperature resistance, small thermal expansion coefficient, and Excellent performance such as corrosion resistance. The aluminum matrix composite material prepared by adding aerogel materials to aluminum and aluminum alloy materials not only has the characteristics of low density and high strength, but also has good thermal and thermal conductivity characteristics, which meets the fields of automobiles, aerospace, power electronics, etc. Application requirements for high-performance lightweight aluminum materials.

It can be seen from the above that the research of aerogel loading various metal materials is still rare. The methods of using aerogel to improve the properties of metals and the new materials obtained can meet various types of fields such as automobiles, aerospace, power electronics, etc. demand. It is necessary to study aerogel-reinforced metal matrix composites and their preparation methods.

Summary of the invention

The invention provides a method for preparing aerogel-reinforced metal-based composite materials, including: obtaining an aerogel; obtaining a metal, which is used as a material matrix; mixing and reacting the aerogel and the metal; wherein, the aerogel The glue includes silicon oxide, aluminum oxide, titanium oxide or zirconium oxide, silicon carbide.

Further, the mixing reaction process is performed at 200 to 1350°C.

Optionally, the preparation method of the aerogel-reinforced metal matrix composite material of the present invention includes: obtaining an aerogel; obtaining a metal; mixing the aerogel and the metal and pressing; wherein, the pressed product is sintered and smelted Or hot extrusion in the mold.

Specifically, the metal includes a metal element, a metal alloy, or a metal-containing salt.

Specifically, the metal includes pure aluminum, deformed aluminum alloy or cast aluminum alloy.

Specifically, the matrix composition of the deformed aluminum alloy is 1XXX series industrial pure aluminum or 2XXX, 3XXX, 4XXX, 5XXX, 6XXX, 7XXX, 8XXX series of deformed aluminum alloy; the matrix composition of the cast aluminum alloy is ZL1XX, ZL2XX, ZL3XX or ZL4XX Cast aluminum alloy.

Further, the aerogel is selected from silicon oxide.

Optionally, the preparation method of the aerogel reinforced metal matrix composite material of the present invention includes: obtaining silicon oxide aerogels, including nano silica aerogels and micro silica aerogels; obtaining metal copper, which As a material matrix; and metallic zinc; after grinding the copper and the silica aerogel, mixing with the zinc and micron silica aerogel, and pressing to obtain a compact; carrying out the compact sintering.

Specifically, the method includes: weighing the powder in proportion, pre-balling the copper and nano-silica mixed powder in a planetary high-energy ball mill, and then mixing it with other raw materials in a V-type mixer, and then mixing In the steel mold, the powder is pressed into a compact with a density of 4 to 5 g/cm ³ ; finally, the compact is sintered in a bell jar furnace.

Further, electrolytic copper, atomized zinc powder, micron-scale silica and nano-silica are used as raw materials.

Further, the average particle size of the electrolytic copper powder is ≤74 μm, and the purity is ≥99.9 wt%; the average particle size of the atomized zinc powder is 40-50 μm, and the purity is ≥98 wt%; the average particle size of the micron-grade SiO ₂ is 40-50 μm, and the moisture content is ≤1 wt% ; The average particle size of nano-SiO ₂ is 20-40nm.

Further, the ball milling time in the high-energy ball mill is 2 to 4 hours, and the mixing time in the V-type mixer is 3 to 5 hours.

Further, when the green compact is sintered in a bell jar furnace, the sintering pressure is 1.0 to 4.0 MPa, the sintering temperature is 800 to 1000°C, the average heating rate is 4 to 7°C/min, and hydrogen reducing protection is used during the sintering process Atmosphere, the sintering time is 20 ~ 40min, and finally the furnace is cooled to room temperature in a protective atmosphere to make a finished product.

Optionally, the method for preparing the aerogel-reinforced metal-based composite material of the present invention includes: obtaining an aerogel; obtaining an aluminum powder, which is used as a material matrix; and mixing the aerogel and the aluminum powder and pressing to obtain a block Mixed aerogel and aluminum powder; massive aerogel and aluminum powder are hot extruded in the mold.

Specifically, the method includes:

1) Place the aerogel particles in absolute ethanol, mechanically stir and ultrasonically treat them to obtain a mixed slurry of aerogel particles and ethanol; then add pure aluminum or aluminum alloy powder to the above mixed slurry, And continue to apply mechanical stirring and ultrasonic treatment to obtain a mixed slurry of aerogel particles and aluminum powder;

2) Put the mixed slurry of aerogel particles and aluminum powder obtained in step 1) in a container, apply mechanical stirring, and distill off the ethanol in the mixed slurry to obtain a mixture of completely dried aerogel particles and aluminum powder powder;

3) Place the mixed powder of aerogel particles and aluminum powder obtained in step 2) in a mold, and perform hot pressing at a set temperature to obtain a bulk aerogel and aluminum powder mixed powder;

4) Place the bulk aerogel particles and aluminum powder mixed powder obtained in step 3) in an extrusion die, and obtain the aerogel reinforced aluminum-based composite material by hot extrusion at a set temperature and extrusion ratio.

Further, the particle size of the pure aluminum or aluminum alloy powder is 60-325 mesh, and the impurity content in the pure aluminum or aluminum alloy powder is ≤0.5 wt.%.

Further, in step 1), the ultrasonic power is 100 to 500 W, and the time is 10 to 60 min; the stirring time of the aerogel particles and the aluminum powder is 10 to 120 min.

Further, in step 2), the distillation temperature when removing ethanol is 60 to 80°C; in step 3), the temperature of the hot pressing of the mixed powder of aerogel and aluminum powder is 200 to 400°C; in step 4), the block The hot extrusion temperature of the mixed aerogel and aluminum powder is 200～450℃, and the extrusion ratio is 10:1～25:1.

Optionally, the preparation method of the aerogel reinforced metal matrix composite material of the present invention includes:

1) Weigh the hydrophilic SiO ₂ aerogel in a three-necked flask according to the mass ratio, add deionized water and Cu(Ac)2·H2O, and ultrasonically disperse it for 1-25 minutes;

2) Water bath at 40°C, and dropwise add hydrazine hydrate aqueous solution under mechanical stirring, and the dropwise addition is completed within 1 hour;

3) After the reaction is completed, the solid is centrifuged, washed with water and ethanol in turn, centrifuged, and the solid is vacuum dried to obtain a silica aerogel-supported copper composite material.

Further, in step 1), the hydrophilic SiO ₂ aerogel weighed by mass ratio is 0.5g, the amount of deionized water added is 10-50mL, and the amount of Cu(Ac)2·H2O added is 10-250mg .

Further, in step 1), the ultrasonic dispersion adopts an ultrasonic processor to perform ultrasonic dispersion processing at a frequency of 40-120 kHz.

Further, in step 2), stirring is performed for 60 min under the condition of 60 to 130 r/min and the dropwise addition of the hydrazine hydrate aqueous solution is completed.

Further, in step 2), the hydrazine hydrate aqueous solution is 98% hydrazine monohydrate or 50% hydrazine hydrate.

Further, in step 3), washing with water and ethanol is soaked three times for 10-15 minutes each time.

Optionally, the preparation method of the aerogel reinforced metal matrix composite material of the present invention includes: obtaining a silicon carbide aerogel; obtaining aluminum powder, which is used as a material matrix; and mixing the aerogel and the aluminum powder for compression Formed into blocks; placed in a vacuum induction furnace and smelted in a molten aluminum. After the intermediate alloy block melted, it was cast into a steel casting mold.

Specifically, the method includes:

1) Preparation of master alloy

Mix the aluminum powder and silicon carbide aerogel weighed according to the ratio in the double-cone high-efficiency mixer;

Then put the mixed powder into the mold and press it into a block under a hydraulic press;

2) Preparation of composite materials

The aluminum-silicon carbide aerogel intermediate alloy block is placed in a vacuum induction furnace and melted in an aluminum liquid at a melting temperature of 1150 to 1350°C. After the intermediate alloy block is melted, it is cast into a steel casting mold.

Further, in step 1), the aluminum powder is pure aluminum powder.

Further, in step 1), the particle size range of the silicon carbide aerogel is 1-30 μm.

Further, in step 1), the content of aerogel in the master alloy is 1-15 wt.%.

Further, in step 1), the powder mixing time of the double-cone high-efficiency mixer is 15 to 45 minutes.

Further, in step 1), the pressing into a block is to press the mixed powder into a middle alloy block in a steel mold.

Further, the average particle size of the pure aluminum powder is ≤150μm, and the impurity content in the pure aluminum powder is ≤0.1wt.%

Further, the average particle size of the micron-scale silicon carbide aerogel is 1-30 μm.

(1) The aerogel particles of a certain quality are mixed with pure aluminum powder or aluminum alloy powder to obtain an aerogel/aluminum precursor.

(2) Add the precursor obtained in step (1) to the molten aluminum solution, and mechanically stir for 5 to 30 minutes, so that the aerogel particles are evenly distributed in the aluminum molten solution.

(3) After performing ultrasonic treatment on the composite material melt obtained in step (2), casting and molding in a metal mold or a sand mold to obtain a high-strength and high-conductivity aluminum-based composite material.

Further, in the aerogel/aluminum precursor obtained in step (1), the content of the aerogel is 1 to 90 wt.%.

Further, when the aluminum alloy melt is stirred in step (2), the temperature range of the melt is 50°C below the liquidus to 100°C above the liquidus.

Further, when the composite material melt is subjected to ultrasonic treatment in step (3), the melt temperature is 20 to 100°C above the liquidus line, and the ultrasonic power per unit weight of the composite material melt is 100 to 1000 W/kg. The processing time is 5 to 30 minutes.

The present invention also proposes an aerogel-reinforced metal-based composite material, the aerogel-reinforced metal-based composite material is obtained by mixing and reacting raw materials including aerogel and metal; wherein, the aerogel includes silicon oxide Substances, aluminum oxide, titanium oxide or zirconium oxide, silicon carbide.

Specifically, the metal The metal includes pure aluminum, deformed aluminum alloy or cast aluminum alloy.

Further, the aerogel is selected from silicon oxide.

Optionally, the aerogel-reinforced metal matrix composite material is a copper-based aerogel-reinforced copper alloy, wherein, in terms of mass percentage, the copper-based aerogel-reinforced copper alloy includes: zinc: 0.5%~ 10%, silica: 2% to 8%, the balance is copper.

Further, in terms of mass percentage, zinc: 1% to 5%, silica: 3% to 6%, and the balance is copper.

Further, the material further contains impurities, and the mass percentage of impurities is ≤0.1%.

The invention also proposes a use of the copper-based aerogel-reinforced copper alloy in the preparation of brake parts.

Optionally, the aerogel reinforced metal matrix composite material is selected from aerogel reinforced aluminum matrix composite materials, the matrix of the composite material is pure aluminum or aluminum alloy, and the reinforced phase of the composite material is aerogel, composite materials The content of aerogel is 0.05 to 5.0 wt.%.

Further, the content of aerogel in the composite material is 0.1-2.0 wt.%.

Further, the content of aerogel in the composite material is 1.0 wt.%.

Further, the matrix composition of the composite material is 1XXX series industrial pure aluminum or 2XXX, 3XXX, 4XXX, 5XXX, 6XXX, 7XXX, 8XXX series aluminum alloys, and 1XXX and 2XXX～8XXX indicate that any number from 1 to 8 starts with Aluminum or aluminum alloy grades.

Further, the aerogel is aerogel particles with a particle size of 0.1-50 μm; the aerogel particle component is silicon oxide, aluminum oxide, titanium oxide or zirconium oxide.

The invention also proposes the use of an aerogel reinforced aluminum-based composite material in the preparation of lightweight aluminum products.

Optionally, the aerogel-reinforced metal-based composite material is selected from silicon carbide aerogel-reinforced aluminum-based composite materials, including an aluminum matrix and a reinforced phase, the aluminum matrix is pure aluminum powder, and the reinforced phase is an aerogel , The aerogel is silicon carbide; the mass percentage composition of the silicon carbide aerogel reinforced aluminum-based composite material is: silicon carbide aerogel: 0-50%, the balance is aluminum.

Further, the silicon carbide aerogel reinforced aluminum-based composite material further contains impurities, and the mass percentage of impurities is ≤0.1%.

Optionally, the aerogel-reinforced metal matrix composite material is selected from high-strength high-conductivity aluminum matrix composite materials, characterized in that the aluminum matrix of the composite material is pure aluminum, deformed aluminum alloy or cast aluminum alloy, and the reinforced phase of the composite material It is aerogel, and the content of aerogel in the composite material is 0.1-40.0wt.%.

Further, the matrix composition of the deformed aluminum alloy is 1XXX series industrial pure aluminum or 2XXX, 3XXX, 4XXX, 5XXX, 6XXX, 7XXX, 8XXX series deformed aluminum alloys.

Further, the matrix composition of the cast aluminum alloy is a ZL1XX, ZL2XX, ZL3XX or ZL4XX series cast aluminum alloy.

Further, the aerogel is silicon oxide, aluminum oxide, titanium oxide or zirconium oxide particles, and the particle size is 0.1-50 μm.

The present invention has conducted in-depth research on aerogel-reinforced metal-based composite materials and preparation methods thereof, and obtained a series of aerogel-loaded various metal materials, which have more excellent properties than the original metal materials . It can meet various needs in the fields of automobiles, aerospace, power electronics and so on.

One embodiment of the present invention improves the mechanical properties, wear resistance and heat resistance of the alloy by adding micron-scale silica and nano-state silica; the addition of zinc can improve the wear resistance and accelerate the process of densification of the matrix; the free state The hard nanoparticles can be distributed between the friction pairs during the friction process, playing a "ball effect", reducing the friction factor and wear rate. When SiO ₂ particles are evenly distributed in the matrix of the copper-based friction material, it can effectively hinder the movement of dislocations and grain boundary slip, and improve the strength and heat resistance of the matrix. The copper-based aerogel-reinforced copper alloy designed by the invention has good processing performance, and has better heat resistance and wear resistance compared with the copper-based aluminum oxide composite material. It uses high-energy ball milling to disperse the nano-silica evenly in the copper matrix to achieve the purpose of improving the overall performance of the composite material, and the prepared copper-based aerogel reinforced copper alloy has lower cost.

One of the embodiments of the present invention adds aerogel particles with a pore structure. The pores in the internal structure are of micro-nano level and high porosity. Therefore, it has the characteristics of light weight, high temperature resistance, corrosion resistance and small thermal expansion coefficient. Aluminum and its alloys can effectively maintain the matrix density, improve the strength of the matrix and other characteristics, and obtain aluminum-based composite materials with good thermal and electrical conductivity. According to the characteristics of aerogel particles, through mechanical stirring and ultrasonic treatment, micron or submicron size aerogel particles and aluminum powder are uniformly mixed, and prepared by subsequent composite materials such as hot pressing and hot extrusion The process can obtain aerogel-reinforced aluminum matrix composite material with uniform structure and good performance. Moreover, the preparation process has high production efficiency, low cost, and wide application range. It is not only suitable for the preparation of composite materials with low aerogel content, but also suitable for preparing aluminum-based composite materials with high aerogel content.

One embodiment of the present invention prepares a silica aerogel load by adding ionized water and Cu(Ac) ₂ ·H ₂ O to a hydrophilic SiO ₂ aerogel, adding dropwise an aqueous solution of hydrazine hydrate, centrifuging, washing, and drying Copper composite material makes the SiO ₂ aerogel loaded with copper, the macro volume does not change significantly, but the density increases, the floating phenomenon in the air is improved, the process is simple, the preparation cycle is short, the silica prepared by this simple method The performance of aerogel-loaded copper composites has been greatly improved. Moreover, the prepared silica aerogel supported copper composite material has the advantage of low cost.

One embodiment of the present invention improves the mechanical properties of aluminum-silicon carbide aerogel composites by adding micron-scale silicon carbide aerogel to pure aluminum, which not only maintains the excellent strength and hardness of aluminum itself, but also significantly Reduces the electrical and thermal conductivity of aluminum alloys. By preparing an aluminum-aerogel intermediate alloy block, the problem that the light aerogel is not easily added to the aluminum melt during the smelting process is solved. Moreover, the aluminum-based silicon carbide aerogel composite material prepared by it has the advantage of low cost, can obtain a large volume, high reinforcement phase content of the composite material, overcome the shortcomings of the traditional powder metallurgy process, suitable for silicon carbide aerogel reinforcement Mass production of aluminum-based composite materials.

In one embodiment of the present invention, by adding aerogel particles with high hardness and low density, the mechanical properties of aluminum and its alloys are greatly improved, and at the same time, the characteristics of low density and good thermal conductivity of the aluminum alloy matrix are effectively maintained. Through the processes of ultrasonic dispersion and semi-solid stirring, the aerogel particles are effectively dispersed in the aluminum alloy matrix, and an aluminum-based composite material with uniform distribution of reinforcing phase particles and uniform structure is obtained. Moreover, the preparation process used is simple, the equipment requirements are low, the production cost is low, the composite material with large volume and high reinforced phase content can be obtained, which overcomes the deficiencies of the traditional powder metallurgy process, and is suitable for the large-scale production of high-strength and high-conductivity aluminum-based composite materials .

BRIEF DESCRIPTION

Figure 1 is the XRD spectrum of SiO ₂ aerogel and Cu@SiO ₂ powder with different Cu loading.

Fig. 2 is an SEM image of Cu@SiO ₂ with different uploading amounts (ad, 1%, 5%, 10%, 15%).

detailed description

To make the objectives, technical solutions, and advantages of the embodiments of the present application clearer, the following describes the specific implementation manners of the technical solutions of the present application in more detail and clearly with reference to the accompanying drawings and embodiments. However, the specific embodiments and examples described below are for illustrative purposes only, and are not intended to limit the present application. It only includes a part of the embodiments of the present application, but not all the embodiments. Other embodiments obtained by those skilled in the art for various changes of the present application are within the protection scope of the present application.

A problem to be solved by the present invention is to provide a copper-based aerogel-reinforced copper alloy material with excellent mechanical properties, wear resistance and heat resistance, and high conductivity, which can be used in aerospace, vehicle transportation, microelectronics and other industries In the field, and to provide a method for preparing a copper alloy aerogel reinforced copper alloy with excellent mechanical properties, wear resistance and heat resistance, and high conductivity.

As an embodiment of the present invention, the present invention provides the following technical solutions:

A copper-based aerogel-reinforced copper alloy, that is, a nano-aerogel (SiO ₂ )-reinforced copper-based composite material, whose mass percentage composition is: zinc: 0.5% to 30%, aerogel (SiO ₂ ) : 2% to 8%, the balance is copper.

As a further solution, the mass percentage composition of the copper-based aerogel reinforced copper alloy is: zinc: 1% to 5%, aerogel (SiO ₂ ): 3% to 6%, and the balance is copper.

Among them, the mass percentage of inevitable impurities ≤ 0.1%.

The functions of the above components in the composite material are as follows:

Zinc: solid solution strengthened copper alloy element, which can improve the mechanical properties of copper alloy materials. Its solid solution β phase has the characteristics of high hardness and good toughness, and can significantly improve the wear resistance of copper alloys.

Aerogel (SiO ₂ ): It has the effect of improving wear resistance, hardness and anti-adhesion of copper-based composite materials. At the same time, due to its nano-effect, it can effectively hinder dislocation motion and grain boundary slip, and has a significant effect on improving the strength of the matrix; on the other hand, the dispersed aerogel second phase can reduce the impact of electron scattering on copper alloy materials. The conductive performance of has a promoting effect.

The preparation method of the copper-based aerogel reinforced copper alloy in this embodiment mainly includes the processes of raw material mixing, cold press forming, and finally pressure sintering. The specific steps include: the preparation method of the copper-based silica composite material, including the following Steps: Weigh the powder in proportion, ball-mill the copper powder and nano-silica in a planetary high-energy ball mill in advance, and then put all the raw materials in a small V-type mixer to mix evenly, and then press the powder into a steel mold Billets with a density of 4 to 5 g/cm ³ ; finally, the compacts are sintered in a bell jar furnace.

Among them, electrolytic copper, atomized zinc powder, micron silica and nano silica are used as raw materials. The quality of the raw materials used is as follows: average particle size of electrolytic copper powder ≤74μm, purity ≥99.9wt%; average particle size of atomized zinc powder is 40-50μm, purity ≥98wt%; average particle size of micron SiO _{2 is} 40-50μm, moisture Content≤1wt%; The average particle size of nano-SiO ₂ is 20～40nm.

First, the copper powder and nano silica are ball milled in a planetary high-energy ball mill for 2 to 4 hours, and then mixed with other raw materials in a V-type mixer for 3 to 5 hours; when the green compact is sintered in a bell jar furnace, Sintering pressure is 1.0～4.0MPa, sintering temperature is 800～1000℃, average heating rate is 4～7℃/min, hydrogen reducing protective atmosphere is used in the sintering process, sintering time is 20～40min, and finally under protective atmosphere The furnace is cooled to room temperature to make a finished product.

The copper-based aerogel reinforced copper alloy obtained above has a tensile strength of 300 to 500 MPa, a yield strength of 200 to 300 MPa, an elongation of 5 to 15%, a dynamic friction coefficient of 0.054 to 0.080, a static friction coefficient of 0.12 to 0.15, and wear Rate 0.3～1.0×10-9cm ³ ·J ^-1 , heat resistance coefficient 35000～50,000, relative heat resistance 1.0～1.5, density 5.5～8g·cm ³ , resistivity 1.8～2.8×10-8Ω·m, hardness 50～85Hv. Compared with the copper-based aluminum oxide composite material, the copper-based aerogel-reinforced copper alloy prepared by the present invention has comparable tensile mechanical properties, but has better thermal conductivity and wear resistance, and at a lower cost. The copper-based aerogel-reinforced copper alloy is used for brake parts.

An issue to be solved by the present invention also includes providing an aerogel-reinforced aluminum-based composite material having mechanical properties such as low density and high strength, and having good electrical and thermal conductivity properties. At the same time, in the face of the problem that the aerogel particles are difficult to disperse during the preparation of aerogel-reinforced aluminum-based composite materials, a method for preparing a gel-reinforced aluminum-based composite material has been specifically developed to solve problem. This method has the advantages of simple process and low production cost. The obtained aluminum-based composite material has low density, at the same time, it has the advantages of excellent mechanical properties and high thermal conductivity. It has a wide range of fields in high-performance aluminum structural parts and automotive, aerospace, power electronics and other fields where aluminum materials have special needs for thermal conductivity. Application prospects.

An aerogel reinforced aluminum-based composite material, the matrix of the composite material is pure aluminum or aluminum alloy, and the reinforced phase of the composite material is aerogel.

As a further solution, the content of the aerogel in the composite material is 0.05 to 5.0 wt.%.

As a further solution, the content of the aerogel in the composite material is 0.1 to 2.0 wt.%.

As a further solution, the content of aerogel in the composite material is 1.0 wt.%.

As a further solution, the matrix composition of the composite material is 1XXX series industrial pure aluminum or 2XXX, 3XXX, 4XXX, 5XXX, 6XXX, 7XXX, 8XXX series aluminum alloys. 1XXX and 2XXX～8XXX represent the aluminum or aluminum alloy grades beginning with any number from 1 to 8 mentioned in the “Deformation Method of Deformed Aluminum and Aluminum Alloy Grades (GB/T16474-2011)” standard.

As a further solution, the aerogel is aerogel particles with a micro-nano cavity structure, and the particle size is 0.1-50 μm.

As a further solution, the aerogel particle component is silica, alumina, titania, or zirconia.

The aerogel-reinforced aluminum-based composite material and its preparation method in this embodiment include the following steps:

(1) Place the aerogel particles in absolute ethanol, mechanically stir and ultrasonically treat them to obtain a mixed slurry of aerogel particles and ethanol; then add pure aluminum or aluminum alloy powder to the above mixed slurry Medium, and continue to apply mechanical stirring and ultrasonic treatment to obtain a mixed slurry of aerogel particles and aluminum powder.

(2) Mix the aerogel particles and aluminum powder slurry obtained in step (1) in a container, apply mechanical stirring, and distill off the ethanol in the mixed slurry to obtain completely dried aerogel particles and aluminum powder Of mixed powder.

(3) Place the mixed powder of aerogel particles and aluminum powder obtained in step (2) in a mold, and perform hot pressing at a set temperature to obtain a bulk aerogel and aluminum powder mixed powder.

(4) Place the bulk aerogel particles and aluminum powder mixed powder obtained in step (3) in an extrusion die, and at a set temperature and extrusion ratio, obtain an aerogel reinforced aluminum matrix composite by hot extrusion material.

As a further solution, the particle size of the pure aluminum or aluminum alloy powder is 60-325 mesh, and the impurity content in the pure aluminum or aluminum alloy powder is ≤0.5 wt.%.

As a further solution, in step (1), the ultrasonic power is 100 to 500 W, and the time is 10 to 60 min.

As a further solution, in step (1), the stirring time of the aerogel particles and the aluminum powder is 10 to 120 min.

As a further solution, in step (2), the distillation temperature when removing ethanol is 60 to 80°C.

As a further solution, in step (3), the temperature of the hot pressing of the mixed powder of aerogel and aluminum powder is 200-400°C.

As a further solution, in step (4), the temperature of the hot extrusion of the mixed powder of the bulk aerogel and the aluminum powder is 200 to 450° C., and the extrusion ratio is 10:1 to 25:1.

The aerogel-reinforced aluminum-based composite material can be used to prepare lightweight aluminum products.

Another embodiment of the present invention provides a method for preparing a silica aerogel-loaded copper composite material, including the following steps:

1) Weigh the hydrophilic SiO ₂ aerogel according to the mass ratio and place it in a three-necked flask, add deionized water and Cu(Ac) ₂ ·H ₂ O, and ultrasonically disperse for 1-25 minutes;

As a further solution of the present invention: in step 1), the hydrophilic SiO ₂ aerogel weighed by mass ratio is 0.5 g, the amount of deionized water added is 10-50 mL, and the added Cu(Ac) ₂ ·H ₂ The amount of O is 10 to 250 mg.

As a further solution of the present invention: In step 1), the ultrasonic dispersion adopts an ultrasonic processor to perform ultrasonic dispersion processing at a frequency of 40-120 kHz.

As a further solution of the present invention: in step 2), stirring is carried out for 60 min under the condition of 60-130 r/min and the dropwise addition of the hydrazine hydrate aqueous solution is completed, and the hydrazine hydrate aqueous solution is 98% hydrazine monohydrate or 50% hydrazine hydrate.

As a further solution of the present invention: in step 3), washing with water and ethanol is soaked three times for 10-15 minutes each time.

Another embodiment of the present invention provides a silicon carbide aerogel reinforced aluminum-based composite material, which includes an aluminum matrix and a reinforced phase. The aluminum matrix is pure aluminum powder, the reinforced phase is aerogel, and the aerogel is silicon carbide ( SiC); silicon carbide (SiC) aerogel exhibits high adsorption capacity and selectivity for high-viscosity organic solvents; silicon carbide aerogel uses silicon carbide nanowires and silicon carbide (SiC) nanowires as a type One-dimensional (1D) nanomaterials with good elasticity, high temperature resistance and chemical stability.

The mass percentage composition of the silicon carbide aerogel reinforced aluminum-based composite material is: silicon carbide aerogel: 0-50%, and the balance is aluminum.

The main function of silicon carbide aerogel in the aluminum matrix is to play the role of dispersion strengthening of the second phase. The scattering effect of the second phase particles on the free electrons is much weaker than that caused by the lattice distortion caused by the solid solution atoms. This makes the aluminum matrix composites have good mechanical properties while maintaining good electrical and thermal conductivity.

The preparation method of the melt casting molding based on the above-mentioned silicon carbide aerogel reinforced aluminum matrix composite material includes the following steps:

(1) Preparation of master alloy

Ingredients: Weigh pure aluminum powder and micron-scale silicon carbide aerogel (particle size range of 1-30 μm) according to the mass ratio, in which the content of aerogel in the intermediate alloy is 1-15 wt.%;

Mixing: Use a double-cone high-efficiency mixer to mix the prepared pure aluminum powder and aerogel evenly. The mixing time is 15～45min;

Cold press forming: pressing the mixed powder into a middle alloy block in a steel mold;

(2) Preparation of composite materials

Smelting: The intermediate alloy block is added to the molten aluminum liquid in the vacuum induction furnace. The melting temperature range is 1150 to 1350°C. After the intermediate alloy block is melted, it is cast into a steel casting mold.

As a further solution: the average particle size of the pure aluminum powder is ≤150 μm, and the impurity content in the pure aluminum powder is ≤0.1 wt.%.

As a further solution: the average particle size of the micron-scale silicon carbide aerogel is 1-30 μm.

The obtained silicon carbide reinforced aluminum matrix composite material has a tensile strength of 400 to 620 MPa, a yield strength of 270 to 500 MPa, an elongation of 6 to 35%, a hardness of 55 to 160 HV, and a density of 400 to 620 MPa after rolling or extrusion molding. 8.80～8.90g/cm3, electrical conductivity 40～57% IACS, thermal conductivity 120～250W/MK. Compared with pure aluminum, the aluminum-based composite material prepared by the invention has improved tensile strength and yield strength, while density and electrical conductivity are significantly reduced.

The problem to be solved by the present invention also includes: in view of the above problems and deficiencies in the development of high-strength high-conductivity aluminum alloys and aluminum-based composite materials, providing a low-density, high-strength aluminum with good electrical and thermal conductivity Base composite material and its preparation method.

A high-strength and high-conductivity aluminum-based composite material. The aluminum matrix of the composite material is pure aluminum, deformed aluminum alloy or cast aluminum alloy, and the reinforced phase of the composite material is aerogel.

Preferably, the content of aerogel in the composite material is 0.1-40.0 wt.%.

Preferably, the matrix composition of the deformed aluminum alloy is the 1XXX series of industrial pure aluminum or 2XXX, 3XXX, 4XXX, 5XXX, 6XXX, 7XXX involved in the standard "Method for expressing grades of deformed aluminum and aluminum alloys (GB/T 16474-2011)" , 8XXX series deformed aluminum alloy.

Preferably, the matrix composition of the cast aluminum alloy is the aluminum alloy grades ZL1XX, ZL2XX, ZL3XX or ZL4XX series cast aluminum alloys involved in the "cast aluminum alloy (GB/T1173-2013)" standard.

Preferably, the aerogel is silicon oxide, aluminum oxide, titanium oxide or zirconium oxide particles, and the particle size is 0.1-50 μm.

The preparation method of the above high-strength and high-conductivity aluminum-based composite material includes the following steps:

Preferably, the particle size of the pure aluminum or aluminum alloy powder is 60-325 mesh, and the impurity content in the pure aluminum or aluminum alloy powder is ≤0.5wt.%.

Preferably, in the aerogel/aluminum precursor obtained in step (1), the content of aerogel is 1 to 90 wt.%.

Preferably, when the aluminum alloy melt is agitated in step (2), the temperature range of the melt is 50°C below the liquidus to 100°C above the liquidus.

Preferably, when the composite material melt is subjected to ultrasonic treatment in step (3), the melt temperature is 20 to 100° C. above the liquidus line, and the ultrasonic power per unit weight of the composite material melt is 100 to 1000 W/kg. The processing time is 5 to 30 minutes.

Preparation of copper-based aerogel reinforced copper alloy

The preparation method of the copper-based aerogel-reinforced copper alloy of the present invention includes the following steps: batching, high-energy ball milling, mixing, cold-press forming, pressure sintering, and finished products. The specific process steps include:

(1) High-energy ball milling: Put the weighed electrolytic copper powder (average particle size ≤74μm, purity ≥99.9wt%), nano-scale SiO ₂ (average particle size 20～40nm) in a planetary high-energy ball mill to pre-ball mill 2 ~4h.

(2) Mixing of raw materials: ball-milled copper-nano SiO ₂ mixed powder, atomized zinc powder (average particle size is 40-50 μm, purity ≥98wt%), micron SiO ₂ (average particle size is 40-50 μm, moisture content ≤1wt%) placed in a small V-type mixer for 3 to 5 hours; the quality of raw materials used in the examples is the same as above.

(2) Cold press forming: Press the powder into a billet with a density of 4-5g/cm ³ in a steel mold of Ф26mm×6.5mm;

(3) Pressure sintering: The green compact is sintered in a bell jar furnace at a pressure of 1.0 to 4.0 MPa, the sintering temperature is 800 to 1000°C, the average heating rate is 4 to 7°C/min, and hydrogen reduction is used in the sintering process In a protective atmosphere, the sintering time is 20 to 40 minutes. Finally, the furnace is cooled to room temperature in a protective atmosphere to make a finished product.

Example 1

The production process flow is as follows: batching, ball milling, mixing, cold press forming, pressure sintering and finished products.

The specific process is as follows: the ingredients are shown in Table 1: zinc: 5%, aerogel (SiO ₂ ): 5%, and the balance is copper. The copper and nano-SiO ₂ (0.5%) mixed powder was ball milled in a high-energy ball mill for 3 hours, and then mixed with other raw materials in a small V-type mixer for 3 hours; the powder was compressed into a density of 26 mm × 6.5 mm in a steel mold 4g/cm ³ billet; sinter the compact in a bell jar furnace at 1.0MPa pressure, the sintering temperature is 980℃, the average heating rate is 6℃/min, a reducing protective atmosphere is used in the sintering process, sintering time It is 40min, and finally the furnace is cooled to room temperature under a protective atmosphere to make a finished product. The properties of the finished product are shown in Table 2.

Example 2

The production process of copper-based aerogel reinforced copper alloy is as follows: batching, ball milling, mixing, cold press forming, pressure sintering and finished products.

The specific process is as follows: ingredients shown in Table 1: zinc: 2%, aerogel (SiO ₂ ): 3%, and the balance is copper. The mixed powder of copper and nano-SiO ₂ (2%) was ball-milled in a high-energy ball mill for 2 hours, and then mixed with other raw materials in a small V-shaped mixer for 5 hours; the powder was compressed into a density of 26 mm × 6.5 mm in a steel mold 4.2g/cm3 billet; sinter the compact in bell jar furnace at 2.5MPa pressure, sintering temperature is 900℃, average heating rate is 5℃/min, adopt hydrogen reducing protective atmosphere during sintering, sinter The time is 35 minutes, and finally the furnace is cooled to room temperature under a protective atmosphere to make a finished product. The properties of the finished product are shown in Table 2.

Example 3

The specific process is as follows: the ingredients are shown in Table 1: zinc: 4%, aerogel (SiO ₂ ): 6%, and the balance is copper. The copper and nano SiO ₂ (1%) mixed powder was ball milled in a high-energy ball mill for 4 hours, and then mixed with other raw materials in a small V-shaped mixer for 5 hours; the powder was compressed into a density of 26 mm × 6.5 mm in a steel mold 4.4g/cm ³ billet; sinter the compact in bell jar furnace at 3.5MPa pressure, the sintering temperature is 800℃, the average heating rate is 5℃/min, the reducing protective atmosphere is used in the sintering process, sintering The time is 40 minutes, and finally the furnace is cooled to room temperature under a protective atmosphere to make a finished product. The properties of the finished product are shown in Table 2.

Example 4

The specific process is as follows: ingredients shown in Table 1: zinc: 1%, aerogel (SiO ₂ ): 6%, and the balance is copper. The copper and nano-SiO ₂ (4.5%) mixed powder was ball milled in a high-energy ball mill for 3 hours, and then mixed with other raw materials in a small V-shaped mixer for 3 hours; the powder was compressed into a density of 26 mm × 6.5 mm in a steel mold 4.6g/cm ³ billet; sinter the compact in a bell jar furnace at a pressure of 2.0MPa, the sintering temperature is 850℃, and the average heating rate is 6℃/min. In the sintering process, a reducing protective atmosphere is used to sinter The time is 30min, and finally the furnace is cooled to room temperature under a protective atmosphere to make a finished product. The properties of the finished product are shown in Table 2.

Example 5

The specific process is as follows: ingredients shown in Table 1: zinc: 5%, aerogel (SiO ₂ ): 4%, and the balance is copper. The mixed powder of copper and nano-SiO ₂ (1%) was ball-milled in a high-energy ball mill for 3 hours, and then mixed with other raw materials in a small V-type mixer for 4 hours; the powder was compressed into a density of 26 mm × 6.5 mm in a steel mold 4.8g/cm ³ billet; sinter the compact in a bell jar furnace under a pressure of 3.0MPa, sintering temperature is 950℃, average heating rate is 6℃/min, reducing protective atmosphere is adopted during sintering, sintering The time is 35 minutes, and finally the furnace is cooled to room temperature under a protective atmosphere to make a finished product. The properties of the finished product are shown in Table 2.

Example 6

The specific process is as follows: the ingredients shown in Table 1: zinc: 0.5%, aerogel (SiO ₂ ): 2%, and the balance is copper. The copper and nano-SiO ₂ (0.5%) mixed powder was ball milled in a high-energy ball mill for 3 hours, and then mixed with other raw materials in a small V-type mixer for 3 hours; the powder was compressed into a density of 26 mm × 6.5 mm in a steel mold 5g/cm ³ billet; sinter the compact in bell jar furnace at 1.0MPa pressure, sintering temperature is 1000℃, average heating rate is 4℃/min, reductive protective atmosphere is adopted during sintering, sintering time It is 25min, and finally the furnace is cooled to room temperature under a protective atmosphere to make a finished product. The properties of the finished product are shown in Table 2.

Example 7

The specific process is as follows: the ingredients shown in Table 1: zinc: 10%, aerogel (SiO ₂ ): 8%, and the balance is copper. The copper and nano-SiO ₂ (0.5%) mixed powder was ball milled in a high-energy ball mill for 3 hours, and then mixed with other raw materials in a small V-type mixer for 3 hours; the powder was compressed into a density of 26 mm × 6.5 mm in a steel mold 4.5g/cm ³ billet; sinter the compact in bell jar furnace at 4.0MPa pressure, sintering temperature is 800℃, average heating rate is 7℃/min, using reducing protective atmosphere during sintering, sintering The time is 40min, and finally the furnace is cooled to room temperature under a protective atmosphere to make a finished product. The performance of the finished product is shown in Table 2.

By adding zinc, micro-scale silica and nano-scale silica, the invention finally improves the comprehensive mechanical properties, wear resistance and heat resistance of the alloy, and at the same time ensures that the alloy has good processing performance; through the method of powder metallurgy, the final A copper-based aerogel reinforced copper alloy is available.

As shown in Table 2, the tensile strength of the copper composite material of the present invention prepared above 300MPa, yield strength and conventional copper-based composite material of aluminum oxide equivalent to the wear rate of less than 1.6 × 10-9cm ³ · J ^{- 1. The} heat resistance coefficient is higher than 27900, the resistivity is lower than 3.2×10 ^-8 cm ³ ·J ^-1 , the density is lower than 8g·cm ³ , the heat resistance and wear resistance are more than copper-based aluminum oxide composites Good, so the wear-resistant parts made of this material can meet the needs of long-term normal operation of products or equipment under higher temperature conditions.

Table 1 Composition of a copper-based silica composite material (wt.%)

实施例Examples	ZnZn	SiO2SiO2	CuCu
实施例1Example 1	5％5%	5％5%	余量margin
实施例2Example 2	2％2%	3％3%	余量margin
实施例3Example 3	4％4%	6％6%	余量margin
实施例4Example 4	1％1%	6％6%	余量margin
实施例5Example 5	5％5%	4％4%	余量margin
实施例6Example 6	0.5％0.5%	2％2%	余量margin
实施例7Example 7	10％10%	8％8%	余量margin

Table 2 Examples and properties of commonly used copper-based composite materials

Preparation of aerogel reinforced aluminum matrix composites

Example 8

The aerogel-reinforced aluminum-based composite material prepared in this example is 200 grams, the aerogel content is 0.05 wt.%, the aerogel component is silicon oxide, and the particle size of the aerogel particles is 0.1 to 0.5 μm. The base alloy is 1060 pure aluminum, the particle size of the aluminum powder is 250-325 mesh, and the impurity content is not more than 0.5wt.%. The specific process is: the weighed aerogel particles are placed in absolute ethanol, the concentration ratio of aerogel to ethanol is 0.25mg/ml, ultrasonic treatment in an ultrasonic cleaning machine for 10min, ultrasonic power is 100W, get dispersed Uniform aerogel and ethanol mixed slurry; Add aluminum powder to the above aerogel and ethanol mixed slurry, mechanically agitate for 60 min, and rotate at 400 r/min to obtain a uniformly mixed aerogel particle and aluminum powder Slurry. After that, the above mixed slurry was poured into a flask, the alcohol in the mixed solution was removed by distillation, and the distillation temperature was controlled to 80° C., to obtain a mixed powder of completely dried aerogel particles and aluminum powder. The mixed powder is placed in a mold and heated to 150°C to be hot pressed into a block, which is then hot extruded. The selected extrusion ratio is 16:1 and the extrusion temperature is 300°C.

Example 9

The aerogel-reinforced aluminum-based composite material prepared in this example is 1000 g, the aerogel content is 0.1 wt.%, the aerogel component is alumina, the particle size of the aerogel particles is 1 to 5 μm, and the matrix It is 2024 aluminum alloy (particle size is 125-175 mesh, impurity content is not more than 0.3wt.%). The specific process is: the weighed aerogel particles are placed in absolute ethanol, the concentration ratio of aerogel to ethanol is 2mg/ml, ultrasonic treatment is carried out in an ultrasonic cleaning machine for 30min, and the ultrasonic power is 500W to obtain uniform dispersion The uniformly dispersed aerogel and ethanol mixed slurry; add aluminum powder to the aerogel and ethanol mixed slurry, mechanically agitate for 60 min, and rotate at 500 r/min to obtain a uniformly mixed aerogel particle and aluminum powder Mix the slurry. After that, the above mixed slurry is poured into a beaker, the alcohol in the mixed solution is removed by distillation, and the distillation temperature is controlled to 80° C. to obtain a mixed powder of completely dried aerogel particles and aluminum powder. The mixed powder is placed in a mold and heated to 200°C to be hot pressed into a block, and then subjected to hot extrusion. The selected extrusion ratio is 16:1 and the extrusion temperature is 400°C.

Example 10

The aerogel-reinforced aluminum-based composite material prepared in this example is 5000 grams, its aerogel content is 1.0 wt.%, the aerogel component is silicon oxide, the particle size of the aerogel particles is 5-20 μm, and the matrix The alloy is 1050 aluminum alloy (particle size is 200-270 mesh, impurity content is not more than 0.2wt.%). The specific process is as follows: the weighed aerogel particles are placed in absolute ethanol, the concentration ratio of aerogel to ethanol is 10 mg/ml, ultrasonic treatment is carried out in an ultrasonic cleaning machine for 30 min, and the ultrasonic power is 300 W to obtain uniform dispersion. Mixed slurry of aerogel and ethanol; add aluminum powder to the mixed slurry of aerogel and ethanol, mechanically agitate for 30min, and rotate at 300r/min to obtain a mixed slurry of aerogel particles and aluminum powder . After that, the above mixed slurry was poured into a three-necked flask, and the alcohol in the mixed liquid was removed by distillation under reduced pressure, and the distillation temperature was controlled to 80°C to obtain a mixed powder of completely dried aerogel particles and aluminum powder. The mixed powder is placed in a mold and heated to 200°C to be hot pressed into a block, and then hot extruded. The selected extrusion ratio is 25:1 and the extrusion temperature is 250°C.

Example 11

The aerogel-reinforced aluminum-based composite material prepared in this example is 500 grams, its aerogel content is 2.0 wt.%, the aerogel component is titanium oxide, the particle size of the aerogel particles is 10-30 μm, and the matrix The alloy is 5052 aluminum alloy (particle size is 60-150 mesh, impurity content is not more than 0.5wt.%). The specific process is as follows: the weighed aerogel particles are placed in absolute ethanol, the concentration ratio of aerogel to ethanol is 25 mg/ml, ultrasonic treatment is carried out in an ultrasonic cleaning machine for 60 min, and the ultrasonic power is 400 W to obtain uniform dispersion. Mixed slurry of aerogel and ethanol; add aluminum powder to the mixed slurry of aerogel and ethanol, mechanically agitate for 90 min, and rotate at 600 r/min to obtain a mixed slurry of aerogel particles and aluminum powder . After that, the above mixed slurry was poured into a flask, and the alcohol in the mixed solution was removed by distillation under reduced pressure, and the distillation temperature was controlled to 60°C to obtain a mixed powder of completely dried aerogel particles and aluminum powder. The mixed powder is placed in a mold and heated to 200°C to be hot pressed into a block, which is then hot extruded. The selected extrusion ratio is 25:1 and the extrusion temperature is 350°C.

Example 12

The aerogel reinforced aluminum-based composite material prepared in this example is 500 grams, its aerogel content is 5.0 wt.%, the aerogel component is zirconia, the particle size of the aerogel particles is 20-50 μm, and the matrix It is 7075 aluminum alloy (the particle size is 120-240 mesh, the impurity content is not more than 0.3wt.%). The specific process is as follows: the weighed aerogel particles are placed in absolute ethanol, the concentration ratio of aerogel to ethanol is 50 mg/ml, ultrasonic treatment is carried out in an ultrasonic cleaning machine for 60 minutes, and the ultrasonic power is 500 W to obtain uniform dispersion. Mixed slurry of aerogel and ethanol; add aluminum powder to the mixed slurry of aerogel and ethanol, mechanically agitate for 120min, and rotate at 500r/min to obtain a mixed slurry of aerogel particles and aluminum powder . After that, the above mixed slurry was poured into a three-necked flask, and the alcohol in the mixed liquid was removed by distillation under reduced pressure, and the distillation temperature was controlled to 75°C to obtain a mixed powder of completely dried aerogel particles and aluminum powder. The mixed powder is placed in a mold and heated to 200°C to be hot pressed into a block, and then subjected to hot extrusion. The selected extrusion ratio is 10:1 and the extrusion temperature is 450°C.

The performance of the aerogel-reinforced aluminum-based composite materials prepared in Example 8 to Example 12 is shown in Table 3.

Table 3 The properties of aerogel reinforced aluminum matrix composites in the examples

The properties of the obtained aerogel-reinforced aluminum matrix composites are shown in Table 3. The prepared pure aluminum matrix composite material has better mechanical properties than the pure aluminum matrix, the density is lower than 2.7g·cm ^-3 and the conductivity is not lower than 55% IACS; the prepared aluminum alloy matrix composite material has mechanical properties Significantly improved, the density is not higher than 2.75g·cm ^-3 , and the conductivity is not lower than 50% IACS. It has high performance in aluminum structural parts and automotive, aerospace, power electronics and other fields that have special needs for thermal conductivity and aluminum materials. Broad application prospects.

Preparation of silica aerogel supported copper composite

Example 13

A method for preparing a silica aerogel-loaded copper composite material includes the following steps:

1) Weigh 0.5g of hydrophilic SiO ₂ aerogel in a three-necked flask according to the mass ratio, add 10 mL of deionized water and 15.7 mg of Cu(Ac) ₂ ·H ₂ O, and sonicate at a frequency of 40 kHz Disperse for 25 minutes;

2) Water bath at 40°C, mechanical stirring under 60r/min, and dropwise addition of hydrazine hydrate aqueous solution, dropwise addition is completed after 1h;

3) After the reaction is completed, the solid is centrifuged, and the solid is washed with water and ethanol successively, soaked three times for 10 minutes each time, centrifuged, and the solid is vacuum dried to obtain a silica aerogel supported copper composite material.

Further, in step 2), the aqueous solution of hydrazine hydrate is 98% hydrazine monohydrate, 0.39 mL.

Further, the reaction time of the present invention is 6h.

Example 14

1) Weigh 0.5g of hydrophilic SiO ₂ aerogel in a three-necked flask according to the mass ratio, add 20 mL of deionized water and 78.5 mg of Cu(Ac) ₂ ·H ₂ O, and sonicate at a frequency of 60 kHz Disperse for 20 minutes;

2) Water bath at 40°C, mechanical stirring under 90r/min, and dropwise addition of hydrazine hydrate aqueous solution, dropwise addition is completed after 1h;

3) After the reaction is completed, the solid is centrifuged, washed with water and ethanol in turn, soaked three times for 12 minutes each time, centrifuged, and the solid is vacuum dried to obtain a silica aerogel supported copper composite material.

Further, in step 2), the aqueous solution of hydrazine hydrate is 50% hydrazine hydrate, 20 mL.

Further, the reaction time of the present invention is 12h.

Example 15

1) Weigh 0.5g of hydrophilic SiO ₂ aerogel in a three-necked flask according to the mass ratio, add 30 mL of deionized water and 157 mg of Cu(Ac) ₂ ·H ₂ O, and ultrasonically disperse at a frequency of 100 kHz 15 minutes;

2) Water bath at 40°C, mechanical stirring under 100r/min, and dropwise addition of hydrazine hydrate aqueous solution, the dropwise addition is completed within 1h;

Further, in step 2), the hydrazine hydrate aqueous solution is 50% hydrazine hydrate, 40 mL.

Further, the reaction time of the present invention is 24h.

Example 16

1) Weigh 0.5g of hydrophilic SiO ₂ aerogel in a three-necked flask according to the mass ratio, add 50mL of deionized water and 235mg of Cu(Ac) ₂ · H ₂ O at a frequency of 40-120kHz Ultrasonic dispersion for 25 minutes;

2) Water bath at 40°C, mechanical stirring under the condition of 130r/min, and dropwise addition of hydrazine hydrate aqueous solution, the dropwise addition is completed within 1h;

3) After the reaction is completed, the solid is centrifuged, washed with water and ethanol in sequence, soaked three times for 15 minutes each time, centrifuged, and the solid is vacuum dried to obtain a silica aerogel-loaded copper composite material.

Further, in step 2), the hydrazine hydrate aqueous solution is 50% hydrazine hydrate, 60 mL.

Further, the reaction time of the present invention is 48h.

Table 4 Preparation conditions of Cu@SiO ₂ in Examples 13-16

Note: a. 98% hydrazine monohydrate; b. 50% hydrazine hydrate. If it is left for a long time, its true purity will decrease.

1. Macro volume observation

According to the observation of different loading Cu@SiO ₂ powders in Examples 13-16, after the SiO ₂ aerogel is loaded with copper, the macro volume does not change significantly, but the density increases and the floating phenomenon in the air improves.

2. XRD analysis

Three distinct diffraction peaks appeared at 2θ of 43.3°, 50.4°, and 74.1, which corresponded to the diffraction of elemental copper (111), (200), and (200) crystal planes of the face-centered cubic crystal (FCC) structure. The peak shape of the diffraction peak is sharp and there are no other peaks, indicating that the crystallinity of copper is very good and the purity is high. The Cu@SiO ₂ diffraction peak of 5% copper loading is not obvious, and the poor crystallinity may be caused by incomplete reduction.

XRD did not find a peak of copper oxide, indicating that there is no CuO or very little.

Figure 1 shows the XRD spectrum of SiO ₂ aerogel and Cu@SiO ₂ powder with different Cu loading.

3. Scanning electron microscope results

As shown in Figure 2, when the copper loading is 1%, no obvious copper nanoparticles are found on the surface of SiO ₂ ; when the loading is 5-15%, copper nanoparticles are deposited on the surface of SiO ₂ aerogel, the size is about 100nm, There is adhesion to each other; increasing the copper mass fraction has a limited effect on the size of the copper nanoparticles, and it is speculated that the deposition thickness should be increased. The 5% copper nanoparticles have completely covered the pores of SiO ₂ aerogel.

It should be pointed out that the present invention is not limited to copper, for example: by adding silica aerogel to the metal, the comprehensive mechanical properties of the composite material are finally improved, and finally the silica aerogel-loaded composite material can be obtained; The method is not limited to one metal and one aerogel. In theory, various metals and aerogels are possible.

Preparation of silicon carbide aerogel reinforced aluminum matrix composites

The preparation steps of the silicon carbide aerogel reinforced aluminum-based composite material of the present invention are:

First, mix a certain ratio of aluminum powder and silicon carbide aerogel in a double-cone high-efficiency mixer for 15 to 45 minutes; then put the uniformly mixed powder into a mold and press it into a block under a hydraulic press; The aerogel intermediate alloy block is smelted in a molten aluminum in a vacuum induction furnace at a melting temperature of 1150 to 1350°C. After the intermediate alloy block is melted, it is cast into a steel casting mold.

Specific steps are as follows:

(1) Preparation of intermediate alloy: batching-mixing-cold pressing molding; (2) Preparation of composite material: vacuum melting-casting molding.

The specific process steps include:

Example 17

Silicon carbide aerogel reinforced aluminum matrix composite material, including aluminum matrix and reinforced phase, the aluminum matrix is pure aluminum, the reinforced phase is aerogel, and the aerogel is silicon carbide (SiC);

Its mass percentage composition is: silicon carbide aerogel: 50%, the balance is aluminum.

The production process of silicon carbide aerogel reinforced aluminum matrix composite material is:

(1) Preparation of Al-SiC aerogel master alloy: batching-mixing-cold pressing molding; (2) Preparation of composite material: induction furnace melting-casting molding.

The specific process is as follows: ingredients according to Table 5.

First, prepare Al-10wt.% SiC aerogel master alloy, mix pure aluminum powder and silicon carbide aerogel in a double-cone high-efficiency mixer for 45 minutes, and then press the mixed powder into a block under a hydraulic press with a pressure of 15MPa . Finally, the molten aluminum and Al-10wt.% SiC master alloy formulated according to the target composition are placed in a vacuum intermediate frequency induction furnace and smelted at 1200°C. After the pure aluminum is melted, the temperature is reduced to 1150°C and poured. The properties of the finished product are shown in Table 6.

Example 18

Silicon carbide aerogel reinforced aluminum matrix composite material, including aluminum matrix and reinforced phase, the aluminum matrix is pure aluminum powder, the reinforced phase is aerogel, and the aerogel is silicon carbide (SiC);

Its mass percentage composition is: silicon carbide aerogel: 45%, the balance is aluminum.

The production process of silicon carbide aerogel reinforced aluminum-based composite materials is: (1) Al-SiC aerogel intermediate alloy preparation: batching-mixing-cold compression molding; (2)composite preparation: vacuum melting- Casting.

The specific process is as follows: ingredients according to Table 5.

First, prepare Al-15wt.% SiC aerogel master alloy, mix pure aluminum powder and silicon carbide aerogel in a double-cone high-efficiency mixer for 45 minutes, and then press the mixed powder into a block under a hydraulic press with a pressure of 15MPa . Finally, the cathode aluminum and Al-15wt.% SiC master alloy formulated according to the target composition are placed in an induction furnace and smelted at 1300°C. After the pure aluminum is melted, the temperature is reduced to 1200°C and poured. The properties of the finished product are shown in Table 6.

Example 19

Its mass percentage composition is: silicon carbide aerogel: 35%, the balance is aluminum.

The specific process is as follows: ingredients according to Table 5.

First, prepare an Al-5wt.% SiC aerogel master alloy, mix pure aluminum powder and silicon carbide aerogel in a double-cone high-efficiency mixer for 45 minutes, and then press the mixed powder into a block under a hydraulic press with a pressure of 15MPa . Finally, the cathode aluminum and Al-5wt.% SiC master alloy formulated according to the target composition are placed in a vacuum intermediate frequency induction furnace and smelted at 1350°C. After the pure aluminum is melted, the temperature is reduced to 1150°C and poured. The properties of the finished product are shown in Table 6.

Example 20

Its mass percentage composition is: silicon carbide aerogel: 25%, the balance is aluminum.

The specific process is as follows: ingredients according to Table 5.

First, prepare an Al-5wt.% SiC aerogel master alloy, mix pure aluminum powder and silicon carbide aerogel in a double-cone high-efficiency mixer for 45 minutes, and then press the mixed powder into a block under a hydraulic press with a pressure of 15MPa . Finally, the cathode aluminum and Al-5wt.% SiC master alloy formulated according to the target composition were placed in a vacuum intermediate frequency induction furnace and melted at 1300°C. After the pure aluminum is melted, the temperature is reduced to 1200°C and poured. The properties of the finished product are shown in Table 6.

Example 21

Its mass percentage composition is: silicon carbide aerogel: 15%, the balance is aluminum.

The specific process is as follows: ingredients according to Table 5.

First, prepare an Al-10wt.% SiC aerogel master alloy, mix pure aluminum powder and silicon carbide aerogel in a double-cone high-efficiency mixer for 15 minutes, and then press the mixed powder into a block under a hydraulic press with a pressure of 15 MPa . Finally, the cathode aluminum and Al-10wt.% SiC master alloy formulated according to the target composition are placed in a vacuum intermediate frequency induction furnace and smelted at 1350°C. After the pure aluminum is melted, the temperature is reduced to 1150°C and poured. The properties of the finished product are shown in Table 6.

Example 22

Its mass percentage composition is: silicon carbide aerogel: 5%, the balance is aluminum.

The specific process is as follows: ingredients according to Table 5.

First, formulate an Al-5wt.% SiC aerogel master alloy, mix pure aluminum powder and silicon carbide aerogel in a double-cone high-efficiency mixer for 15 minutes, and then press the mixed powder into a block with a pressure of 15 MPa under a hydraulic press . Finally, the cathode aluminum and Al-5t.% SiC master alloy formulated according to the target composition are placed in a vacuum intermediate frequency induction furnace and smelted at 1350°C. After the pure aluminum is melted, the temperature is reduced to 1150°C and poured. The properties of the finished product are shown in Table 6.

Table 5 The composition of aerogel reinforced aluminum matrix composites (wt.%)

Table 6 Examples 17-22 and properties of intermediate alloy ingots

In the present invention, by adding micron-scale silicon carbide aerogel to pure aluminum, the comprehensive mechanical properties of the composite material are finally improved, and finally the silicon carbide aerogel reinforced aluminum-based composite material can be obtained. Moreover, as a modification of the present invention, by adding micron-scale silicon carbide aerogel to the metal, the comprehensive mechanical properties of the composite material are finally improved, and finally the silicon carbide aerogel reinforced metal matrix composite material can be obtained. In addition, the method is not limited to one metal and one aerogel. In theory, various metals and aerogels are possible.

Preparation of high-strength and high-conductivity aluminum matrix composites

Example 23

The total weight of the high-strength and high-conductivity aluminum-based composite material prepared in this example is 5000 grams, the aerogel content is designed to be 20.0% (weight percentage, the same below), the aerogel component is zirconia, the aerogel particles The particle size is 10～20μm; the base alloy is 1100 aluminum alloy with impurity content not more than 0.1wt.%, and the rest is Al. The specific process is: mixing aerosol particles of a certain quality with pure aluminum alloy powder (aluminum powder particle size is 200 mesh, impurity content is not more than 0.5wt.%) to obtain aerogel with aerogel content of 90wt.% Aluminum precursor; add aerogel/aluminum precursor to molten aluminum liquid at 690℃ (about 30℃ higher than alloy liquidus line), and mechanically stir for 30min, so that the aerogel is evenly distributed in the molten liquid; The composite melt is heated to 720°C (about 60°C above the alloy liquidus line) and subjected to ultrasonic treatment for 20 minutes. The ultrasonic power is 2500W. After the ultrasound is completed, it is insulated and cast in a metal mold to obtain its gas condensation A high-strength and high-conductivity aluminum matrix composite material blank with a glue content of 40.0%. Subsequently, the composite billet is subjected to hot extrusion and cold drawing, with an extrusion ratio of 81:1 and a drawing ratio of 25:1, and finally a high-strength and high-conductivity aluminum matrix composite wire is obtained. The properties of the prepared high-strength and high-conductivity aluminum matrix composites are shown in Table 7.

Example 24

The high-strength and high-conductivity aluminum-based composite material prepared in this example is 1000 grams, and its aerogel content is designed to be 40.0% (weight percent, the same below), the aerogel composition is silicon oxide, and the particle size of the aerogel particles is 15～30μm; the base alloy is 1050 aluminum alloy, the impurity content is not more than 0.05wt.%, and the rest is Al. The specific process is: mixing aerosol particles of a certain quality with pure aluminum alloy powder (aluminum powder particle size is 325 mesh, impurity content is not more than 0.1wt.%), to obtain an aerogel with aerogel content of 80wt.% Aluminum precursor; add aerogel/aluminum precursor to molten aluminum at 720°C (about 60°C above the alloy liquidus) and mechanically stir for 15 min to make the aerogel evenly distributed in the melt; The composite melt is heated to 680°C (about 20°C above the alloy liquidus line), and subjected to ultrasonic treatment for 20 minutes with an ultrasonic power of 1000W. After the ultrasound is completed, it is insulated and cast into a sand mold to obtain an aerogel A high strength and high conductivity aluminum matrix composite billet with a content of 40.0%. The composite billet is subjected to hot extrusion and cold drawing, with an extrusion ratio of 81:1 and a drawing ratio of 16:1, and finally a high-strength and high-conductivity aluminum matrix composite wire is obtained. The properties of the prepared high-strength and high-conductivity aluminum matrix composites are shown in Table 7.

Example 25

The high-strength and high-conductivity aluminum-based composite material prepared in this example is 2000 grams, its aerogel content is 0.1% (weight percentage, the same below), the aerogel component is silicon oxide, and the particle size of the aerogel particles is 5 ～10μm; the base alloy is ZL101, the impurity content does not exceed 0.2%, and the rest is Al. The specific process is: mixing aerosol particles of a certain quality with aluminum alloy powder (aluminum powder particle size is 300 mesh, impurity content is not more than 0.2%) to obtain an aerogel/aluminum precursor with aerogel content of 1%; Add the aerogel/aluminum precursor to the molten aluminum at 595°C (about 20°C below the alloy liquidus line) and stir for 5 min to make the aerogel evenly distributed in the melt; heat the composite melt To 715 ℃ (about 100 ℃ higher than the liquidus line of the alloy), ultrasonic treatment for 5 minutes, ultrasonic power 200W, heat preservation after the end of ultrasound, and casting in a metal mold to obtain a high strength of aerogel content of 0.1% High conductivity aluminum matrix composite material blank. The properties of the prepared high-strength and high-conductivity aluminum matrix composites are shown in Table 7.

Example 26

The high-strength and high-conductivity aluminum-based composite material prepared in this example is 2000 grams, its aerogel content is 2.0% (weight percent, the same below), the aerogel component is titanium oxide, and the particle size of the aerogel particles is 40 ~50μm; the base alloy is ZL203, the impurity content does not exceed 0.2%, and the rest is Al. The specific process is: mixing aerosol particles of certain quality with aluminum alloy powder (aluminum powder particle size is 60 mesh, impurity content is not more than 0.2%) to obtain aerogel/aluminum precursor with aerogel content of 10%; Add the aerogel/aluminum precursor to the molten aluminum liquid at 600°C (about 50°C below the alloy liquidus line) and stir for 10 min to make the aerogel evenly distributed in the melt; heat the composite melt To 700 ℃ (about 50 ℃ above the liquidus), ultrasonic treatment for 10 minutes, ultrasonic power 600W, heat preservation after the end of the ultrasonic, and casting in a metal mold to obtain a high strength of aerogel content of 2.0% High conductivity aluminum matrix composite material blank. The properties of the prepared high-strength and high-conductivity aluminum matrix composites are shown in Table 7.

Example 27

The high-strength high-conductivity aluminum-based composite material prepared in this example is 5000 grams, its aerogel content is 5.0% (weight percent, the same below), the aerogel component is silicon oxide, and the particle size of the aerogel particles is 0.1 ～1μm; base alloy is 6061, impurity content does not exceed 0.15%, the rest is Al. The specific process is: mixing aerosol particles of a certain quality with aluminum alloy powder (aluminum powder particle size is 150 mesh, impurity content is not more than 0.2wt.%) to obtain aerogel/aluminum with aerogel content of 20wt.% Precursor; add aerogel/aluminum precursor to molten aluminum at 660°C (about 10°C above the alloy liquidus) and stir for 15 min to make the aerogel evenly distributed in the melt; mix the composite The melt was heated to 730 ℃ (about 80 ℃ higher than the liquidus line of the alloy), and subjected to ultrasonic treatment for 15 min. The ultrasonic power was 2000 W. After the ultrasonic was completed, it was insulated and was cast into a sand mold to obtain an aerogel content of 5.0% high strength and high conductivity aluminum matrix composite material blank. The composite billet is subjected to hot extrusion and cold drawing, with an extrusion ratio of 81:1 and a drawing ratio of 9:1, and finally a high-strength and high-conductivity aluminum matrix composite material profile is obtained. The properties of the prepared high-strength and high-conductivity aluminum matrix composites are shown in Table 7.

Example 28

The high-strength high-conductivity aluminum-based composite material prepared in this example is 5000 grams, its aerogel content is 10.0% (weight percent, the same below), the aerogel component is silicon oxide, and the particle size of the aerogel particles is 1 ～5μm; the base alloy is 5005, the impurity content does not exceed 0.15%, and the rest is Al. The specific process is: mixing a certain amount of aerogel particles with aluminum alloy powder (aluminum powder particle size is 100 mesh, impurity content is not more than 0.2wt.%) to obtain aerogel/aluminum with aerogel content of 40wt.% Precursor; add aerogel/aluminum precursor to molten aluminum at 640°C (about 10°C below the alloy liquidus) and stir for 20 min to make the aerogel evenly distributed in the melt; dissolve the melt Heated to 680 ℃ (about 30 ℃ higher than the alloy liquidus), subjected to ultrasonic treatment for 15 minutes, ultrasonic power 3000W, heat preservation after the end of ultrasound, and casting in a sand mold to obtain an aerogel content of 10.0% High strength and high conductivity aluminum matrix composite material blank. The composite billet is subjected to hot extrusion and cold drawing, with an extrusion ratio of 81:1 and a drawing ratio of 9:1, and finally a high-strength and high-conductivity aluminum matrix composite material profile is obtained. The properties of the prepared high-strength and high-conductivity aluminum matrix composites are shown in Table 7.

The properties of the high-strength and high-conductivity aluminum-based composite material obtained by the present invention are shown in Table 1. The present invention obtains an aluminum-based composite material with uniform aerogel distribution and uniform structure by applying agitation in the liquid or semi-solid interval of the aluminum alloy and performing ultrasonic treatment on the composite material melt. In addition, the obtained aluminum-based composite material can be subjected to plastic forming processing such as extrusion, rolling, drawing, etc. to further obtain a deformed aluminum-based composite material with more excellent mechanical properties. The invention solves the technical problem of uniform and effective dispersion of submicron and micron level aerogel particles in an aluminum alloy matrix, has the advantages of simple process and low production cost, and is suitable for large-scale mass production of high-strength and high-conductivity aluminum-based composite materials . The mechanical properties of the prepared composite materials are better than pure aluminum or aluminum alloy matrix, and the density is less than 2.75g·cm ^-3 , while maintaining good electrical conductivity, in high-performance aluminum structural parts and thermal conductivity Special requirements for aluminum materials in the automotive, aerospace, power electronics and other fields have broad application prospects.

Table 7 Composition and properties of high-strength and high-conductivity aluminum matrix composites in the examples

It should be noted that the embodiments described above with reference to the drawings are only used to illustrate the present application and not to limit the scope of the present application. Those of ordinary skill in the art should understand that without departing from the spirit and scope of the present application Modifications or equivalent substitutions made to this application shall be covered within the scope of this application. In addition, unless the context indicates otherwise, words in the singular include the plural and vice versa. In addition, unless specifically stated otherwise, all or part of any embodiment may be used in combination with all or part of any other embodiment.

Claims

A method for preparing aerogel reinforced metal matrix composite material, characterized in that it includes,

Obtain aerogel;

Obtain a metal, which serves as a material matrix;

Mixing and reacting the aerogel and the metal; wherein,

The aerogel includes silicon oxide, aluminum oxide, titanium oxide or zirconium oxide, and silicon carbide.
The method of claim 1, wherein:

The mixing reaction process is carried out at 200 to 1350°C.
The method of claim 1, comprising:

Obtain aerogel;

Get metal

Pressing the aerogel and metal after mixing; wherein,

After pressing, the product is sintered, smelted, or hot extruded in a mold.
The method of claim 1, wherein:

The metals include elemental metals, metal alloys or metal-containing salts.
The method of claim 4, wherein:

The metal includes pure aluminum, deformed aluminum alloy or cast aluminum alloy.
The method of claim 5, wherein:

The matrix composition of the deformed aluminum alloy is 1XXX series industrial pure aluminum or 2XXX, 3XXX, 4XXX, 5XXX, 6XXX, 7XXX, 8XXX series of deformed aluminum alloy; the matrix composition of the cast aluminum alloy is ZL1XX, ZL2XX, ZL3XX or ZL4XX series cast aluminum alloy.
The method of claim 1, wherein:

The aerogel is selected from silicon oxide.
The method of claim 1, comprising:

Obtain silicon oxide aerogels, including nano silica aerogels and micro silica aerogels;

Obtaining metallic copper as a material matrix; and metallic zinc;

Grinding the copper and the silica aerogel, mixing with the zinc and micron silica aerogel, and pressing to obtain a compact;

The compact is sintered.
The method of claim 8, comprising:

Weigh the powder in proportion, mix the copper and nano-silica powder in a planetary high-energy ball mill in advance, and then mix it with other raw materials in a V-type mixer to mix evenly, and then press the powder into a density in a steel mold It is 4～5g/cm 3 billet; finally, the compact is sintered in bell jar furnace.
The method according to claim 8, characterized in that electrolytic copper, atomized zinc powder, micron-scale silica and nano-silica are used as raw materials.
The method according to claim 10, characterized in that the average particle size of the electrolytic copper powder is ≤74μm, and the purity is ≥99.9wt%; the average particle size of the atomized zinc powder is 40-50μm, the purity is ≥98wt%; and the average particle size of the micron SiO 2 It is 40-50 μm, moisture content ≤1wt%; the average particle size of nano-SiO 2 is 20-40 nm.
The method according to claim 10, wherein the ball milling time in the high-energy ball mill is 2 to 4 hours, and the mixing time in the V-type mixer is 3 to 5 hours.
The method according to claim 12, wherein when the compact is sintered in a bell jar furnace, the sintering pressure is 1.0 to 4.0 MPa, the sintering temperature is 800 to 1000°C, and the average heating rate is 4 to 7°C/min In the sintering process, a hydrogen-reducing protective atmosphere is used. The sintering time is 20 to 40 minutes. Finally, the furnace is cooled to room temperature under a protective atmosphere to make a finished product.
The method of claim 1, comprising:

Obtain aerogel;

Obtain aluminum powder, which is used as the material matrix;

The aerogel and the aluminum powder are mixed and then compressed to obtain a bulk aerogel and aluminum powder mixed powder;

The mixed powder of massive aerogel and aluminum powder is hot extruded in the die.
The method of claim 14, comprising:

1) Place the aerogel particles in absolute ethanol, mechanically stir and ultrasonically treat them to obtain a mixed slurry of aerogel particles and ethanol; then add pure aluminum or aluminum alloy powder to the above mixed slurry, And continue to apply mechanical stirring and ultrasonic treatment to obtain a mixed slurry of aerogel particles and aluminum powder;

2) Put the mixed slurry of aerogel particles and aluminum powder obtained in step 1) in a container, apply mechanical stirring, and distill off the ethanol in the mixed slurry to obtain a mixture of completely dried aerogel particles and aluminum powder powder;

3) Place the mixed powder of aerogel particles and aluminum powder obtained in step 2) in a mold, and perform hot pressing at a set temperature to obtain a bulk aerogel and aluminum powder mixed powder;

4) Place the bulk aerogel particles and aluminum powder mixed powder obtained in step 3) in an extrusion die, and obtain the aerogel reinforced aluminum-based composite material by hot extrusion at a set temperature and extrusion ratio.
The method according to claim 15, wherein the particle size of the pure aluminum or aluminum alloy powder is 60-325 mesh, and the impurity content in the pure aluminum or aluminum alloy powder is ≤0.5 wt.%.
The method according to claim 16, characterized in that, in step 1), the ultrasonic power is 100-500W, and the time is 10-60min; the stirring time of the aerogel particles and the aluminum powder is 10-120min.
The method according to claim 17, characterized in that, in step 2), the distillation temperature when removing ethanol is 60 to 80°C; in step 3), the temperature of hot pressing of the mixed powder of aerogel and aluminum powder is 200 ~400°C; in step 4), the temperature of hot extrusion of the mixed powder of bulk aerogel and aluminum powder is 200-450°C, and the extrusion ratio is 10:1-25:1.
The method according to claim 7, characterized in that

1) Weigh the hydrophilic SiO2 aerogel according to the mass ratio and place it in a three-necked flask, add deionized water and Cu(Ac)2·H2O, and ultrasonically disperse for 1-25 minutes;

2) Water bath at 40°C, and dropwise add hydrazine hydrate aqueous solution under mechanical stirring, and the dropwise addition is completed within 1 hour;

3) After the reaction is completed, the solid is centrifuged, washed with water and ethanol successively, centrifuged, and the solid is vacuum dried to obtain a silica aerogel supported copper composite material.
The method according to claim 19, wherein in step 1), the hydrophilic SiO2 aerogel weighed by mass ratio is 0.5g, the amount of deionized water added is 10-50mL, and the added Cu(Ac )2·H2O amount is 10～250mg.
The method according to claim 20, wherein in step 1), the ultrasonic dispersion adopts an ultrasonic processor to perform ultrasonic dispersion processing at a frequency of 40-120 kHz.
The method according to claim 21, characterized in that, in step 2), stirring is carried out at 60 to 130 r/min for 60 minutes to complete the dropwise addition of the hydrazine hydrate aqueous solution.
The method according to claim 22, wherein in step 2), the aqueous hydrazine hydrate solution is 98% hydrazine monohydrate or 50% hydrazine hydrate.
The method according to claim 23, characterized in that, in step 3), water and ethanol are washed and soaked three times for 10-15 minutes each time.
The method of claim 1, comprising:

Obtain silicon carbide aerogel;

Obtain aluminum powder, which is used as the material matrix;

The aerogel and the aluminum powder are mixed and then pressed into a block;

It is melted in a molten aluminum in a vacuum induction furnace. After the intermediate alloy block is melted, it is cast into a steel casting mold.
The method of claim 25, wherein the steps are as follows:

1) Preparation of master alloy

Mix the aluminum powder and silicon carbide aerogel weighed according to the ratio in the double-cone high-efficiency mixer;

Then put the mixed powder into the mold and press it into a block under a hydraulic press;

2) Preparation of composite materials

The aluminum-silicon carbide aerogel intermediate alloy block is placed in a vacuum induction furnace and melted in an aluminum liquid at a melting temperature of 1150 to 1350°C. After the intermediate alloy block is melted, it is cast into a steel casting mold.
The method according to claim 26, wherein in step 1), the aluminum powder is pure aluminum powder.
The method according to claim 27, wherein in step 1), the particle size range of the silicon carbide aerogel is 1-30 μm.
The method according to claim 28, wherein in step 1), the content of the aerogel in the intermediate alloy is 1 to 15 wt.%.
The method according to claim 29, wherein in step 1), the powder mixing time of the double-cone high-efficiency mixer is 15 to 45 minutes.
The method according to claim 30, characterized in that, in step 1), the pressing into blocks is to press the mixed powder into a middle alloy block in a steel mold.
The method according to claim 31, wherein the average particle size of the pure aluminum powder is ≤150μm, and the impurity content in the pure aluminum powder is ≤0.1wt.%
The method according to claim 32, wherein the average particle size of the micron-scale silicon carbide aerogel is 1-30 μm.
The method according to claim 5, comprising:

(1) The aerogel particles of a certain quality are mixed with pure aluminum powder or aluminum alloy powder to obtain an aerogel/aluminum precursor.

(2) Add the precursor obtained in step (1) to the molten aluminum solution, and mechanically stir for 5 to 30 minutes, so that the aerogel particles are evenly distributed in the aluminum molten solution.

(3) After performing ultrasonic treatment on the composite material melt obtained in step (2), casting and molding in a metal mold or a sand mold to obtain a high-strength and high-conductivity aluminum-based composite material.
The method according to claim 34, wherein the particle size of the pure aluminum or aluminum alloy powder is 60-325 mesh, and the impurity content in the pure aluminum or aluminum alloy powder is ≤0.5wt.%.
The method according to claim 35, wherein in the aerogel/aluminum precursor obtained in step (1), the content of the aerogel is 1 to 90 wt.%.
The method according to claim 36, wherein in the step (2), when the aluminum alloy melt is stirred, the temperature range of the melt is 50°C below the liquidus to 100°C above the liquidus.
The method according to claim 37, characterized in that, in step (3), when the composite material melt is subjected to ultrasonic treatment, the melt temperature is 20 to 100°C above the liquidus line, and the corresponding weight of the composite material melt corresponds to The ultrasonic power is 100～1000W/kg, and the ultrasonic treatment time is 5～30min.
The aerogel-reinforced metal matrix composite material produced by the method of claim 1, wherein the aerogel-reinforced metal matrix composite material is obtained by mixing and reacting raw materials including aerogel and metal; wherein, The aerogel includes silicon oxide, aluminum oxide, titanium oxide or zirconium oxide, and silicon carbide.
The aerogel reinforced metal matrix composite material according to claim 39, characterized in that

The metal The metal includes pure aluminum, deformed aluminum alloy or cast aluminum alloy.
The aerogel reinforced metal matrix composite material according to claim 40, wherein

The matrix composition of the deformed aluminum alloy is 1XXX series industrial pure aluminum or 2XXX, 3XXX, 4XXX, 5XXX, 6XXX, 7XXX, 8XXX series of deformed aluminum alloy; the matrix composition of the cast aluminum alloy is ZL1XX, ZL2XX, ZL3XX or ZL4XX series cast aluminum alloy.
The aerogel reinforced metal matrix composite material according to claim 39, characterized in that

The aerogel is selected from silicon oxide.
The aerogel reinforced metal matrix composite material according to claim 42, wherein

The aerogel-reinforced metal-based composite material is a copper-based aerogel-reinforced copper alloy, wherein, in terms of mass percentage, the copper-based aerogel-reinforced copper alloy includes: zinc: 0.5% to 10%, two Silicon oxide: 2% to 8%, the balance is copper.
The aerogel reinforced metal matrix composite material according to claim 43, characterized in that, in terms of mass percentage, zinc: 1% to 5%, silica: 3% to 6%, and the balance is copper.
The aerogel reinforced metal matrix composite material according to claim 44, characterized in that the material further contains impurities, and the mass percentage of impurities is ≤0.1%.
A use of the aerogel reinforced metal matrix composite material according to any one of claims 43-45 in the preparation of brake parts.
The aerogel reinforced metal matrix composite material according to claim 39, wherein the aerogel reinforced metal matrix composite material is selected from aerogel reinforced aluminum matrix composite materials, characterized in that the matrix of the composite material is pure aluminum or For the aluminum alloy, the reinforced phase of the composite material is aerogel, and the content of the aerogel in the composite material is 0.05 to 5.0 wt.%.
The aerogel reinforced metal matrix composite material according to claim 47, wherein the content of the aerogel in the composite material is 0.1-2.0 wt.%.
The aerogel reinforced metal matrix composite material according to claim 48, characterized in that the content of aerogel in the composite material is 1.0 wt.%.
The aerogel reinforced metal matrix composite material according to any one of claims 47-49, wherein the matrix composition of the composite material is 1XXX series industrial pure aluminum or 2XXX, 3XXX, 4XXX, 5XXX, 6XXX, 7XXX, For 8XXX series aluminum alloys, 1XXX and 2XXX to 8XXX indicate aluminum or aluminum alloy grades beginning with any number from 1 to 8.
The aerogel reinforced metal matrix composite material according to claim 50, wherein the aerogel is aerogel particles with a particle size of 0.1-50 μm; the aerogel particles are composed of silica, alumina, Titanium oxide or zirconium oxide.
The use of the aerogel reinforced metal matrix composite material according to any one of claims 47-51 in the preparation of lightweight aluminum products.
The aerogel reinforced metal matrix composite material according to claim 40, wherein the aerogel reinforced metal matrix composite material is selected from silicon carbide aerogel reinforced aluminum matrix composite materials, including an aluminum matrix and a reinforced phase In two parts, the aluminum matrix is pure aluminum powder, the reinforcement phase is aerogel, and the aerogel is silicon carbide; the mass percentage composition of the silicon carbide aerogel reinforced aluminum matrix composite is: silicon carbide aerogel: 0-50 %, the balance is aluminum.
The aerogel reinforced metal matrix composite material according to claim 53, wherein the silicon carbide aerogel reinforced aluminum matrix composite material further contains impurities, and the mass percentage of the impurities is ≤0.1%.
The aerogel-reinforced metal matrix composite material according to claim 40, the aerogel-reinforced metal matrix composite material is selected from high-strength high-conductivity aluminum-based composite materials, characterized in that the aluminum matrix of the composite material is pure aluminum, deform Aluminum alloy or cast aluminum alloy, the reinforced phase of the composite material is aerogel, and the content of aerogel in the composite material is 0.1-40.0wt.%.
The aerogel reinforced metal matrix composite material according to claim 55, wherein the matrix composition of the deformed aluminum alloy is 1XXX series industrial pure aluminum or 2XXX, 3XXX, 4XXX, 5XXX, 6XXX, 7XXX, 8XXX series deformed aluminum alloy.
The aerogel reinforced metal matrix composite material according to claim 55, characterized in that the matrix composition of the cast aluminum alloy is a ZL1XX, ZL2XX, ZL3XX or ZL4XX series cast aluminum alloy.
The aerogel reinforced metal matrix composite material according to claim 55, wherein the aerogel is silicon oxide, aluminum oxide, titanium oxide or zirconium oxide particles, and the particle size is 0.1-50 μm.