Composite material based on ceramic and aluminum alloy and preparation method thereof

Abstract

The invention belongs to the technical field of metal-based composite materials, and particularly relates to a composite material based on ceramic and aluminum alloy and a preparation method thereof.The composite material comprises the following raw materials of, by weight, 82-88 parts of modified aluminum alloy powder, 12-18 parts of modified silicon carbide powder, 0.35-0.45 part of a composite sintering aid and 0.2-0.3 part of a dispersing agent; preparing modified aluminum alloy powder through surface activation, chemical nickel plating and rare earth doping; preparing modified silicon carbide powder through fluotitanic acid treatment, aluminum-zirconium coating and silicon dioxide coating; the preparation method comprises the following steps: ball-milling and mixing all the components, drying and sieving, and then carrying out cold press molding, stepped heating degreasing and sintering densification under the protection of argon to finally obtain the composite material. Through multi-scale interface modification, the compatibility and binding force of the ceramic and an aluminum matrix are remarkably enhanced, and the obtained product is good in wear resistance, high in hardness and excellent in mechanical property and corrosion resistance.

Description

Technical Field

[0001] This invention relates to the field of metal matrix composites technology, and more specifically to a composite material based on ceramics and aluminum alloys and its preparation method. Background Technology

[0002] With the acceleration of industrialization, materials science has also made significant progress. Especially in high-end fields such as aerospace, automotive, electronics, and energy, the demand for high-strength, high-toughness, high-temperature resistance, corrosion resistance, and wear resistance aluminum alloy composites is constantly increasing. Ceramic-aluminum alloy matrix composites are widely used in extreme environments such as high temperature, friction, and corrosion due to their excellent mechanical properties and high-temperature resistance. However, traditional ceramic-aluminum alloy composites still face some technical bottlenecks. First, the interfacial bonding between ceramic particles and the metal matrix is ​​not strong, resulting in the composite material's performance not being fully realized under high temperature and mechanical loading. Second, the wear resistance and corrosion resistance of the composite material are still not ideal, especially in humid, high-temperature, or acidic environments, which limits its applicability in some demanding scenarios.

[0003] Chinese patent application CN202310209341.9 discloses a dual-scale ceramic particle reinforced aluminum matrix composite material and its preparation method. This composite material consists of 25% to 75% ceramic particles and the balance aluminum alloy powder. The ceramic particles include fine ceramic particles and coarse ceramic particles in a mass ratio of (0.5-1.5):1. The D50 of the fine ceramic particles ranges from 15 μm to 30 μm, while the D50 of the coarse ceramic particles is between 100 μm and 200 μm. The D50 of the aluminum alloy powder is also between 15 μm and 30 μm. However, the aluminum matrix has poor wettability with common ceramics such as silicon carbide and alumina, resulting in weak bonding between the ceramic particles and the aluminum matrix. Under stress, these particles become crack initiation points, directly reducing strength and affecting performance. Chinese patent application CN202211645960.4 discloses a high-strength die-cast aluminum alloy and its preparation method. The preparation method mainly includes the following steps: S1, preparing a cermet; S2, melting; S3, die-casting. By adding cermet, the high-strength die-cast aluminum alloy can effectively pin dislocations during the deformation process of the aluminum alloy, thereby improving the material's strength. Furthermore, La exists in a solid solution form in the (Ti,La)(C,N)-based cermet, which can reduce the segregation of aluminum alloy elements and combine with impurity elements at the interface to achieve grain boundary purification. Simultaneously, the cermet possesses high hardness, and its combination with the aluminum alloy can significantly improve the hardness level of the aluminum alloy. However, highly reactive elements such as Mg and Y in the aluminum melt have high solubility and reactivity with Ti, C, and N elements in the ceramic, especially C and N elements, which react with the aluminum melt to form brittle aluminum carbide and aluminum nitride. These reaction layers severely weaken the bonding force between the reinforcing phase and the matrix, becoming crack sources and leading to a decline in the composite material's performance.

[0004] Therefore, developing a ceramic and aluminum alloy-based composite material that combines high strength, high toughness, high wear resistance, and excellent corrosion resistance, while optimizing the preparation process to meet the needs of industrial production, has become an urgent technical problem to be solved in this field. Summary of the Invention

[0005] To address the aforementioned problems, this invention provides a composite material based on ceramics and aluminum alloys and its preparation method. The method involves a complex process of etching aluminum alloy powder with oxalic acid and phosphoric acid, post-treatment with molybdate / tungstate, electroless nickel plating, and cerium salt modification. It also involves multi-step modification of silicon carbide powder, including fluorotitanic acid treatment, aluminum zirconium nitrate deposition, and tetraethyl orthosilicate coating. The modified powder is then ball-milled with sintering aids and dispersants, dried, and sieved. Finally, a molding process combined with a degreasing-sintering process that strictly controls the heating rate and atmosphere at multiple stages is employed to obtain the composite material based on ceramics and aluminum alloys.

[0006] The technical solution of the present invention to solve the above problems is as follows:

[0007] A composite material based on ceramics and aluminum alloys comprises the following raw materials in parts by weight: 82-88 parts of modified aluminum alloy powder, 12-18 parts of modified silicon carbide powder, 0.35-0.45 parts of composite sintering aid, and 0.2-0.3 parts of dispersant;

[0008] The modified aluminum alloy powder is prepared as follows:

[0009] Step S1: Dissolve oxalic acid and phosphoric acid solutions in deionized water, then add aluminum alloy powder, react at 45-50℃ for 1-1.5h, and obtain product 1 after post-treatment;

[0010] Step S2: Dissolve nickel sulfate, sodium hypophosphite, sodium citrate, sodium acetate, and ammonium bifluoride in deionized water in sequence, then adjust the pH to 9.2±0.1, add product 1, and react with ultrasound at 70-75℃ for 2.5-3 hours. After post-processing, obtain product 2.

[0011] Step S3: Dissolve cerium nitrate hexahydrate, citric acid, and ethylene glycol in a mixed solvent, add product 2, react at 60-65℃ for 3-3.5h, adjust the pH to 6.2±0.1, then vacuum dry at 150-155℃ for 3-3.5h, keep warm at 495-505℃ for 1-1.5h, add lanthanum oxide and ball mill for 30-40min to obtain modified aluminum alloy powder.

[0012] Further, in step S1, the mass ratio of oxalic acid, aluminum alloy powder, and deionized water is 2.5-3.5:5:50-60, and the volume ratio of phosphoric acid solution and deionized water is 2.5-3.5:200.

[0013] Further, in step S2, the mass ratio of nickel sulfate, sodium hypophosphite, sodium citrate, sodium acetate, ammonium bifluoride, deionized water, and product 1 is 0.95-1.05:7-8:10-11:5.5-6.5:0.8-1:290-310:20.

[0014] Further, the mixed solvent in step S3 is prepared from anhydrous ethanol and deionized water in a volume ratio of 7:2.8-3.2, and the mass ratio of cerium nitrate hexahydrate, citric acid, ethylene glycol, product 2, and lanthanum oxide is 9.5-10.5:4.5-5.5:3-3.5:200:0.03-0.05, and the mass-volume ratio of product 2 to the mixed solvent is 1.5-2.5 g / 10 mL.

[0015] The modified silicon carbide powder is prepared as follows:

[0016] Step a: Add silicon carbide to an aqueous solution of fluorotitanic acid and react at 50-55°C for 1.5-2 hours. After post-treatment, product a is obtained.

[0017] Step b: Dissolve aluminum nitrate and zirconium nitrate in deionized water in sequence, then adjust the pH value to 8.0±0.1, add product a, and reflux at 75-80℃ for 3-3.5h. After post-processing, product b is obtained.

[0018] Step c: Add tetraethyl orthosilicate to the solvent, adjust the pH to 4.8±0.1, stir at room temperature for 2-2.5 h, add product b, ultrasonically disperse for 30-40 min, then adjust the pH to 8.5±0.1, and obtain modified silicon carbide powder after post-treatment.

[0019] Further, in step a, the mass-to-volume ratio of silicon carbide and fluorotitanic acid aqueous solution is 0.95-1.05 g / 20 mL, and the mass percentage concentration of fluorotitanic acid aqueous solution is 8.5-9.5%.

[0020] Further, in step b, the mass ratio of aluminum nitrate, zirconium nitrate, product a, and deionized water is 1.3-1.7:0.7-0.8:1.8-2.2:30.

[0021] Further, in step c, the volume ratio of tetraethyl orthosilicate to solvent is 0.98-1.02:10, the solvent is composed of anhydrous ethanol and deionized water in a volume ratio of 3.95-4.05:1, and the mass-volume ratio of product b to solvent is 1.95-2.05 g / 5 mL.

[0022] Furthermore, the composite sintering aid is composed of magnesium oxide and trimethyl borate in a mass ratio of 1.9-2.1:1, and the dispersant is polyethylene glycol.

[0023] A method for preparing a composite material based on ceramics and aluminum alloys includes the following steps: mixing modified aluminum alloy powder, modified silicon carbide powder, composite sintering aid, and dispersant, then molding, degreasing, and sintering to obtain the final product.

[0024] The present invention has the following beneficial effects:

[0025] This invention achieves a significant leap in the overall performance of a ceramic-aluminum alloy-based composite material system through a multi-scale interface matching design of modified aluminum alloy powder and modified silicon carbide powder. Firstly, the modified aluminum alloy powder, after multiple surface modifications, and the modified silicon carbide powder jointly construct a strong and stable multi-level interface structure. The modified aluminum alloy powder not only enhances its strength and hardness through the introduction of nickel-phosphorus coating and rare earth elements, but its surface properties also serve as an ideal flexible transition layer, providing an excellent bonding foundation for the introduction of the ceramic reinforcing phase. Simultaneously, the multi-layer ceramic coating (containing titanium compounds, aluminum zirconium oxide, and silicon dioxide) on the surface of the modified silicon carbide powder greatly improves its physical wettability and chemical compatibility with the aluminum alloy matrix. During subsequent sintering, these two modified raw materials achieve a robust interface connection from mechanical interlocking to metallurgical bonding, effectively alleviating internal stress caused by the mismatch in thermal expansion coefficients, preventing interface failure, and laying a microscopic foundation for the material's superior macroscopic properties. Secondly, the rational use of composite sintering aids and dispersants enhances the uniformity and sintering performance of the material. Composite sintering aids improve the sintering density and structural stability of the composite material by adjusting the atmosphere and temperature during the sintering process, while the addition of dispersants ensures the uniform dispersion of modified aluminum alloy powder and modified silicon carbide powder, avoids powder agglomeration, and further optimizes the microstructure of the composite material, thereby improving its mechanical strength, hardness and wear resistance.

[0026] The synergistic effect of the raw materials results in a composite material exhibiting significant advantages in mechanical properties, wear resistance, and corrosion resistance. In terms of mechanical properties, the strong and tough aluminum alloy matrix efficiently transfers loads to the high-strength silicon carbide particles through an optimized interface, giving the material both high strength and good toughness, significantly improving its load-bearing capacity. Regarding wear resistance, the hard silicon carbide particles, as the main wear-resistant component, are strongly supported by the hardened and highly supportive modified matrix. The synergistic effect of the modified silicon carbide and modified aluminum alloy effectively resists wear, prevents premature detachment of the reinforcing phase, and greatly extends service life. In terms of corrosion resistance, the enhanced corrosion resistance of the modified aluminum alloy matrix, combined with the interfacial isolation effect brought about by the dense coating layer on the surface of the modified silicon carbide particles, jointly constructs an effective corrosion protection barrier, significantly improving the material's durability in harsh environments. Therefore, this invention, by optimizing the raw material ratio and processing technology, fully leverages the synergistic effect between the components to prepare a high-performance ceramic-aluminum alloy composite material with broad application prospects, particularly showing outstanding application advantages in wear resistance and corrosion resistance. Attached Figure Description

[0027] Figure 1 The graph shows the test results of tensile strength, yield strength and elongation at break of the ceramic and aluminum alloy-based composite materials prepared in Examples 1-4 and Comparative Examples 1-4 of this invention.

[0028] Figure 2 The graph shows the test results of hardness and wear resistance of the ceramic and aluminum alloy-based composite materials prepared in Examples 1-4 and Comparative Examples 1-4 of this invention. Figure 3 The graph shows the corrosion resistance test results of the composite materials based on ceramics and aluminum alloys prepared in Examples 1-4 and Comparative Examples 1-4 of this invention. Detailed Implementation

[0029] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0030] All raw materials used in the following examples are commercially available products. The aluminum alloy powder is 7075 aluminum alloy powder, 15-53μm, with an effective component content of 99.9%, sourced from Nangong Rongbang New Material Technology Co., Ltd.; the silicon carbide has a purity of 98% and a density of... Particle size 50nm, Henan Nuoda New Material Co., Ltd.; Boron nitride release agent with 99.9% effective ingredient content and 300 mesh particle size, Qinghe County Chaoneng Alloy Material Co., Ltd.; Silica with particle size ≤20nm and content 99.8wt%, Qinghe County Chaotai Metal Material Co., Ltd.; Polyethylene glycol with 99% effective ingredient content and density... Hunan Qilu New Materials Technology Co., Ltd.

[0031] Example 1

[0032] A composite material based on ceramics and aluminum alloys comprises the following raw materials in parts by weight: 82 parts modified aluminum alloy powder, 12 parts modified silicon carbide powder, 0.35 parts composite sintering aid, and 0.2 parts dispersant;

[0033] The modified aluminum alloy powder is prepared as follows:

[0034] Step S1: Dissolve oxalic acid and phosphoric acid solutions in deionized water, then add aluminum alloy powder, and react at 47℃ for 1.2 hours at 200 rpm. After the reaction, wash three times with deionized water. Add sodium molybdate and sodium tungstate to the last washing solution, soak for 10 minutes, centrifuge, and then dry at 100℃ for 2 hours in an argon atmosphere to obtain product 1. The mass ratio of oxalic acid, aluminum alloy powder, and deionized water is 3:5:55, the volume ratio of phosphoric acid solution to deionized water is 3:200, the mass percentage concentration of phosphoric acid solution is 85%, and the mass percentage concentrations of sodium molybdate and sodium tungstate in the washing solution are 0.1% and 0.05%, respectively.

[0035] Step S2: Dissolve nickel sulfate, sodium hypophosphite, sodium citrate, sodium acetate, and ammonium bifluoride sequentially in deionized water. Adjust the pH to 9.2±0.1 with ammonia. Add product 1 and react at 73°C with 40kHz, 200W ultrasonic assistance for 2.7 hours at 150rpm. After the reaction, centrifuge at 6000rpm for 5 minutes, wash three times with deionized water, and vacuum dry at 120°C for 3 hours. Keep the dried solid at 500°C for 1 hour under an argon atmosphere with a heating rate of 3°C / min. Cool with the furnace to obtain product 2. The mass ratio of nickel sulfate, sodium hypophosphite, sodium citrate, sodium acetate, ammonium bifluoride, deionized water, and product 1 is 1:7.5:10.5:6:0.9:300:20.

[0036] Step S3: Cerium nitrate hexahydrate, citric acid, and ethylene glycol are dissolved in a mixed solvent. Product 2 is added, and the mixture is reacted at 63°C for 3.2 h at a rotation speed of 150 rpm. The pH value is adjusted to 6.2 ± 0.1 with 0.5 M ammonia water. Then, the mixture is vacuum dried at 153°C for 3.2 h and kept at 500°C for 1.3 h under an argon atmosphere. Lanthanum oxide is added and the mixture is ball-milled for 35 min to obtain modified aluminum alloy powder. The ball-to-material mass ratio is 3:1, and the rotation speed is 100 rpm. Large, medium, and small zirconia balls with diameters of 8 mm, 5 mm, and 2 mm are used, with a ratio of 4:3.5:2.5. The mixed solvent is prepared from anhydrous ethanol and deionized water in a volume ratio of 7:3. The mass ratio of cerium nitrate hexahydrate, citric acid, ethylene glycol, product 2, and lanthanum oxide is 10:5:3.3:200:0.04, and the mass-to-volume ratio of product 2 to the mixed solvent is 2 g / 10 mL.

[0037] The modified silicon carbide powder is prepared as follows:

[0038] Step a: Add silicon carbide to a fluorotitanic acid aqueous solution and react at 53℃ for 1.7h at 300rpm. After the reaction, centrifuge at 10000rpm for 5min, discard the supernatant, add half the volume of deionized water to the fluorotitanic acid solution, and sonicate at 40KHz and 300W for 5min. Centrifuge again, and repeat this centrifugation-sonication-centrifugation cycle until the pH of the supernatant is 6.8-7.2. Vacuum freeze the washed powder for 24h, place the dried powder in a tube furnace, introduce high-purity argon gas at a flow rate of 200mL / min, heat to 150℃ at 3℃ / min, hold for 2h, and cool with the furnace to obtain product a, wherein the mass-volume ratio of silicon carbide to fluorotitanic acid aqueous solution is 1g / 20mL, and the mass percentage concentration of fluorotitanic acid aqueous solution is 9%.

[0039] Step b: Dissolve aluminum nitrate and zirconium nitrate in deionized water in sequence, then adjust the pH to 8.0±0.1 with 1M ammonium bicarbonate solution, add product a, reflux at 78℃ for 3.3h at 250rpm, centrifuge at 8000rpm for 5min while hot after the reaction, discard the supernatant, wash the precipitate 3 times with anhydrous ethanol, put the washed powder into a tube furnace, introduce argon gas, heat to 450℃ at 5℃ / min, hold for 2h, cool with the furnace to obtain product b, wherein the mass ratio of aluminum nitrate, zirconium nitrate, product a, and deionized water is 1.5:0.75:2:30;

[0040] Step c: Add tetraethyl orthosilicate to the solvent, adjust the pH to 4.8±0.1 with 0.5M glacial acetic acid solution, stir at room temperature for 2.3h, add product b, and ultrasonically disperse at 40KHz, 300W for 35min. Then adjust the pH to 8.5±0.1 with 0.5M ammonia water, and vacuum dry at 120℃ for 4h. Then transfer to a tube furnace, introduce argon gas containing 5vol% water vapor, heat to 550℃ at 2℃ / min, and hold for 1h to obtain modified silicon carbide powder. The volume ratio of tetraethyl orthosilicate to solvent is 1:10, and the solvent is composed of anhydrous ethanol and deionized water in a volume ratio of 4:1. The mass-volume ratio of product b to solvent is 2g / 5mL.

[0041] The composite sintering aid is composed of magnesium oxide and trimethyl borate in a mass ratio of 2:1, and the dispersant is polyethylene glycol.

[0042] The above-mentioned preparation method of composite materials based on ceramics and aluminum alloys includes the following steps: Dispersant is ultrasonically dispersed at 40 kHz and 200 W for 15 min and added to a mixed solvent of anhydrous ethanol and deionized water in a volume ratio of 7:3. The total mass of the mixed solvent is 60% of the total mass of the powder. Then, modified aluminum alloy powder, modified silicon carbide powder, and composite sintering aid are ball-milled for 6 h, with the mill stopped and scraped every 1.5 h at a speed of 180 rpm. The ball-to-powder mass ratio is 4:1, and the grinding balls are 8 mm, 5 mm, and 2 mm zirconia balls with a mass ratio of 4:3:2.5. After ball milling, the slurry is transferred to a vacuum degassing machine and degassed at -0.09 MPa for 30 min. Then, it is vacuum dried at 80℃ for 8 h and passed through a 100-mesh sieve to obtain a mixed powder. The mixed powder is then loaded into a graphite mold. The inner wall of the mold is pre-coated with boron nitride release agent. The green embryo is obtained by holding the pressure at 280 MPa for 3 min, with a pressure increase / decrease rate ≤10 MPa / min. During the degreasing stage (vacuum degree ≤10 Pa), the temperature is first increased from room temperature to 150°C at a rate of 1°C / min and held for 1 h. Then, the temperature is increased to 300°C at a rate of 0.5°C / min and held for 2 h. Next, the temperature is increased to 450°C at a rate of 2°C / min and held for 1 h. Under a vacuum degree ≤5 Pa, the temperature is increased to 550°C at a rate of 3°C / min and held for 1 h. Under an argon atmosphere with a gas flow rate of 80 mL / min, the temperature is increased to 580°C at a rate of 1°C / min and held for 3.5 h. Finally, the furnace is cooled to 300°C, the argon gas is turned off, and the furnace is cooled further to below 60°C to obtain the final product.

[0043] Example 2

[0044] A composite material based on ceramics and aluminum alloys comprises the following raw materials in parts by weight: 88 parts modified aluminum alloy powder, 18 parts modified silicon carbide powder, 0.45 parts composite sintering aid, and 0.3 parts dispersant;

[0045] The preparation methods for the modified aluminum alloy powder and the modified silicon carbide powder are the same as in Example 1.

[0046] The composite sintering aid and dispersant are the same as in Example 1.

[0047] The preparation method of the above-mentioned composite material based on ceramics and aluminum alloys is the same as that in Example 1.

[0048] Example 3

[0049] A composite material based on ceramics and aluminum alloys comprises the following raw materials in parts by weight: 85 parts modified aluminum alloy powder, 16 parts modified silicon carbide powder, 0.4 parts composite sintering aid, and 0.25 parts dispersant.

[0050] The preparation methods for the modified aluminum alloy powder and the modified silicon carbide powder are the same as in Example 1.

[0051] The composite sintering aid and dispersant are the same as in Example 1.

[0052] The preparation method of the above-mentioned composite material based on ceramics and aluminum alloys is the same as that in Example 1.

[0053] Example 4

[0054] A composite material based on ceramics and aluminum alloys comprises the following raw materials in parts by weight: 85 parts modified aluminum alloy powder, 16 parts modified silicon carbide powder, 0.4 parts composite sintering aid, and 0.25 parts dispersant.

[0055] The modified aluminum alloy powder is prepared as follows:

[0056] Step S1: Dissolve oxalic acid and phosphoric acid solutions in deionized water, then add aluminum alloy powder, and react at 50℃ for 1.5h at 200rpm. After the reaction, wash three times with deionized water. Add sodium molybdate and sodium tungstate to the last washing solution, soak for 10min, centrifuge, and then dry at 100℃ for 2h in an argon atmosphere to obtain product 1. The mass ratio of oxalic acid, aluminum alloy powder, and deionized water is 3.5:5:60, the volume ratio of phosphoric acid solution to deionized water is 3.5:200, the mass percentage concentration of phosphoric acid solution is 85%, and the mass percentage concentrations of sodium molybdate and sodium tungstate in the washing solution are 0.1% and 0.05%, respectively.

[0057] Step S2: Dissolve nickel sulfate, sodium hypophosphite, sodium citrate, sodium acetate, and ammonium bifluoride sequentially in deionized water. Adjust the pH to 9.2±0.1 with ammonia. Add product 1 and react at 75°C with 40kHz, 200W ultrasonic assistance for 3 hours at 150rpm. After the reaction, centrifuge at 6000rpm for 5 minutes, wash three times with deionized water, and vacuum dry at 120°C for 3 hours. Keep the dried solid at 500°C for 1 hour under an argon atmosphere with a heating rate of 3°C / min. Cool in the furnace to obtain product 2. The mass ratio of nickel sulfate, sodium hypophosphite, sodium citrate, sodium acetate, ammonium bifluoride, deionized water, and product 1 is 1.05:8:11:6.5:1:310:20.

[0058] Step S3: Cerium nitrate hexahydrate, citric acid, and ethylene glycol are dissolved in a mixed solvent. Product 2 is added, and the mixture is reacted at 65°C for 3.5 h at a rotation speed of 150 rpm. The pH value is adjusted to 6.2 ± 0.1 with 0.5 M ammonia water. Then, the mixture is vacuum dried at 155°C for 3.5 h and held at 505°C for 1.5 h under an argon atmosphere. Lanthanum oxide is added and the mixture is ball-milled for 35 min to obtain modified aluminum alloy powder. The ball-to-material mass ratio is 3:1, and the rotation speed is 100 rpm. Large, medium, and small zirconia balls with diameters of 8 mm, 5 mm, and 2 mm are used, with a ratio of 4:3.5:2.5. The mixed solvent is prepared from anhydrous ethanol and deionized water in a volume ratio of 7:3.2. The mass ratio of cerium nitrate hexahydrate, citric acid, ethylene glycol, product 2, and lanthanum oxide is 10.5:5.5:3.5:200:0.05, and the mass-to-volume ratio of product 2 to the mixed solvent is 2.5 g / 10 mL.

[0059] The modified silicon carbide powder is prepared as follows:

[0060] Step a: Add silicon carbide to a fluorotitanic acid aqueous solution and react at 55℃ for 2 hours at 300 rpm. After the reaction, centrifuge at 10000 rpm for 5 minutes, discard the supernatant, add half the volume of deionized water to the fluorotitanic acid solution, and sonicate at 40 kHz and 300 W for 5 minutes. Centrifuge again, and repeat this centrifugation-sonication-centrifugation cycle until the pH of the supernatant is 6.8-7.2. Vacuum freeze the washed powder for 24 hours, place the dried powder in a tube furnace, introduce high-purity argon gas at a flow rate of 200 mL / min, heat to 150℃ at 3℃ / min, hold for 2 hours, and cool with the furnace to obtain product a, in which the mass-volume ratio of silicon carbide to fluorotitanic acid aqueous solution is 1.05 g / 20 mL, and the mass percentage concentration of fluorotitanic acid aqueous solution is 9.5%.

[0061] Step b: Dissolve aluminum nitrate and zirconium nitrate in deionized water in sequence, then adjust the pH to 8.0±0.1 with 1M ammonium bicarbonate solution, add product a, reflux at 80℃ for 3.5h at 250rpm, after the reaction is completed, centrifuge at 8000rpm for 5min while hot, discard the supernatant, wash the precipitate 3 times with anhydrous ethanol, put the washed powder into a tube furnace, introduce argon gas, heat to 450℃ at 5℃ / min, hold for 2h, cool with the furnace to obtain product b, wherein the mass ratio of aluminum nitrate, zirconium nitrate, product a, and deionized water is 1.7:0.8:2.2:30;

[0062] Step c: Add tetraethyl orthosilicate to the solvent, adjust the pH to 4.8±0.1 with 0.5M glacial acetic acid solution, stir at room temperature for 2.5h, add product b, and ultrasonically disperse at 40KHz, 300W for 40min. Then adjust the pH to 8.5±0.1 with 0.5M ammonia water, and vacuum dry at 120℃ for 4h. Then transfer to a tube furnace, introduce argon gas containing 5vol% water vapor, heat to 550℃ at 2℃ / min, and hold for 1h to obtain modified silicon carbide powder. The volume ratio of tetraethyl orthosilicate to solvent is 1.02:10, and the solvent is composed of anhydrous ethanol and deionized water with a volume ratio of 4.05:1. The mass-volume ratio of product b to solvent is 2.05g / 5mL.

[0063] The composite sintering aid is composed of magnesium oxide and trimethyl borate in a mass ratio of 2.1:1, and the dispersant is polyethylene glycol.

[0064] The preparation method of the above-mentioned composite material based on ceramics and aluminum alloys is the same as that in Example 1.

[0065] Comparative Example 1

[0066] A composite material based on ceramics and aluminum alloys comprises the following raw materials in parts by weight: 50 parts modified aluminum alloy powder, 10 parts modified silicon carbide powder, 0.4 parts composite sintering aid, and 0.25 parts dispersant.

[0067] The modified aluminum alloy powder is prepared as follows:

[0068] Step S1: Dissolve oxalic acid and phosphoric acid solutions in deionized water, then add aluminum alloy powder. React at room temperature for 1.5 hours at 200 rpm. After the reaction, wash three times with deionized water. Add sodium molybdate and sodium tungstate to the last washing solution, soak for 10 minutes, centrifuge, and then dry at 100°C for 2 hours in an argon atmosphere to obtain product 1. The mass ratio of oxalic acid, aluminum alloy powder, and deionized water is 1:5:60, the volume ratio of phosphoric acid solution to deionized water is 2:200, the mass percentage concentration of phosphoric acid solution is 85%, and the mass percentage concentrations of sodium molybdate and sodium tungstate in the washing solution are 0.1% and 0.05%, respectively.

[0069] Step S2: Dissolve nickel sulfate, sodium hypophosphite, sodium citrate, sodium acetate, and ammonium bifluoride sequentially in deionized water. Adjust the pH to 9.2±0.1 with ammonia. Add product 1 and react at 75°C with 40kHz, 200W ultrasonic assistance for 1 hour at 150rpm. After the reaction, centrifuge at 6000rpm for 5 minutes, wash three times with deionized water, and vacuum dry at 120°C for 3 hours. Keep the dried solid at 500°C for 1 hour under an argon atmosphere with a heating rate of 3°C / min. Cool with the furnace to obtain product 2. The mass ratio of nickel sulfate, sodium hypophosphite, sodium citrate, sodium acetate, ammonium bifluoride, deionized water, and product 1 is 1.05:5:11:6.5:1:310:10.

[0070] Step S3: Cerium nitrate hexahydrate, citric acid, and ethylene glycol are dissolved in a mixed solvent. Product 2 is added, and the mixture is reacted at 65°C for 3.5 h at a rotation speed of 150 rpm. Then, it is vacuum dried at 155°C for 3.5 h and held at 505°C for 1.5 h under an argon atmosphere. Lanthanum oxide is added and the mixture is ball-milled for 35 min to obtain modified aluminum alloy powder. The ball-to-material mass ratio is 3:1, and the rotation speed is 100 rpm. Large, medium, and small zirconia balls with diameters of 8 mm, 5 mm, and 2 mm are used, with a ratio of 4:3.5:2.5. The mixed solvent is prepared from anhydrous ethanol and deionized water in a volume ratio of 7:3.2. The mass ratio of cerium nitrate hexahydrate, citric acid, ethylene glycol, product 2, and lanthanum oxide is 5:5.5:3.5:200:0.01, and the mass-to-volume ratio of product 2 to the mixed solvent is 2.5 g / 10 mL.

[0071] The modified silicon carbide powder is prepared as follows:

[0072] Step a: Add silicon carbide to a fluorotitanic acid aqueous solution and react at room temperature for 2 hours at 300 rpm. After the reaction, centrifuge at 10,000 rpm for 5 minutes, discard the supernatant, add half the volume of deionized water to the fluorotitanic acid solution, and sonicate at 40 kHz and 300 W for 5 minutes. Centrifuge again, and repeat this centrifugation-sonication-centrifugation cycle until the pH of the supernatant is 6.8-7.2. Vacuum freeze the washed powder for 24 hours, place the dried powder in a tube furnace, introduce high-purity argon gas at a flow rate of 200 mL / min, heat to 150 °C at 3 °C / min, hold for 2 hours, and cool with the furnace to obtain product a, in which the mass-volume ratio of silicon carbide to fluorotitanic acid aqueous solution is 2 g / 20 mL, and the mass percentage concentration of fluorotitanic acid aqueous solution is 9.5%.

[0073] Step b: Dissolve aluminum nitrate and zirconium nitrate in deionized water in sequence, then adjust the pH to 8.0±0.1 with 1M ammonium bicarbonate solution, add product a, reflux at 80℃ for 1 h at 250 rpm, centrifuge at 8000 rpm for 5 min while hot after the reaction, discard the supernatant, wash the precipitate 3 times with anhydrous ethanol, put the washed powder into a tube furnace, introduce argon gas, heat to 450℃ at 5℃ / min, hold for 2 h, and cool with the furnace to obtain product b, wherein the mass ratio of aluminum nitrate, zirconium nitrate, product a, and deionized water is 1.7:0.8:1:30;

[0074] Step c: Add tetraethyl orthosilicate to the solvent and stir at room temperature for 2.5 h. Add product b and ultrasonically disperse at 40 kHz and 300 W for 40 min. Then vacuum dry at 120 °C for 4 h. Transfer to a tube furnace, introduce argon gas containing 5 vol% water vapor, heat to 550 °C at 2 °C / min, and hold for 1 h to obtain modified silicon carbide powder. The volume ratio of tetraethyl orthosilicate to solvent is 1.02:10. The solvent consists of anhydrous ethanol and deionized water in a volume ratio of 4.05:1. The mass-volume ratio of product b to solvent is 1 g / 5 mL.

[0075] The composite sintering aid is composed of magnesium oxide and trimethyl borate in a mass ratio of 2.1:1, and the dispersant is polyethylene glycol.

[0076] The preparation method of the above-mentioned composite material based on ceramics and aluminum alloys is the same as that in Example 1.

[0077] Comparative Example 2

[0078] In this comparative example, commercially available aluminum alloy powder was used instead of modified aluminum alloy powder, and all other aspects were the same as in Example 1.

[0079] Comparative Example 3

[0080] In this comparative example, commercially available silicon carbide powder was used instead of modified silicon carbide powder, and all other aspects were the same as in Example 1.

[0081] Comparative Example 4

[0082] In this comparative example, commercially available aluminum alloy powder was used instead of modified aluminum alloy powder, and commercially available silicon carbide powder was used instead of modified silicon carbide powder. All other aspects were the same as in Example 1.

[0083] The properties of the high-strength paper forming wire fibers prepared in Examples 1-4 and Comparative Examples 1-4 were tested, and the results are recorded in Table 1. Figure 1-2 .

[0084] Mechanical properties: Tensile strength, yield strength, and elongation at break were tested according to GB / T 228.1-2021 "Metallic materials, tensile testing—Part 1: Tests at room temperature"; wear resistance and coefficient of friction were tested according to GB / T 12444-2006 "Metallic materials, wear test—sliding wear test of test rings and blocks". F m Friction force (in N), nominal normal force (in N), test load 100 N, sliding speed 0.42 m / s, test time 30 min; hardness was tested according to GB / T 4340.1-2024 "Metallic materials Vickers hardness test - Part 1: Test method", test force HV5 (49.03 N), loading time 15 s, hardness was measured at 6 points at each location, and the average value was taken;

[0085] Corrosion resistance: The corrosion resistance was tested according to GB / T 10125-2021 "Artificial Atmosphere Corrosion Test - Salt Spray Test". A 5% NaCl solution was selected and treated by continuous spraying at 35±2℃ for 240h. Then the tensile strength, yield strength and elongation at break were tested.

[0086] Table 1 Performance Tests

[0087] According to Table 1 and Figure 1-2 The data shown demonstrate that the ceramic-aluminum alloy-based composite materials prepared in Examples 1-4 exhibit excellent mechanical properties, with superior tensile strength, yield strength, elongation at break, wear resistance, and hardness. After corrosion resistance testing, the composite material still maintains high tensile strength, yield strength, and elongation at break, indicating excellent corrosion resistance. Compared to Comparative Example 1, all examples show significantly better performance, confirming that the technical solution of this invention, including the raw material ratio and technical parameters, has a significant optimizing effect on the overall material performance.

[0088] From Table 1 and Figure 1-2It can be seen that the mechanical properties and corrosion resistance of the composite material prepared in Comparative Example 2 decreased. This is because commercially available aluminum alloy powder replaced the modified aluminum alloy powder. In step S1 of the example, the oxide film was simultaneously stripped by synergistic etching with oxalic acid and phosphoric acid. The targeted adsorption of sodium molybdate and sodium tungstate pre-placed refractory metal elements on the powder surface, providing a highly active reaction interface for subsequent sintering. At high temperature, molybdenum and tungsten elements are converted into hard oxide dispersed phases, which improve the matrix's resistance to plastic deformation through solid solution strengthening mechanism. At the same time, the composite passivation structure of phosphate conversion film and refractory metal oxide effectively blocks the penetration of corrosive media, improving the corrosion resistance of the composite material. In step S2 of the embodiment, the chemical nickel plating process constructs a Ni-P alloy coating layer on the surface of the aluminum alloy. Ultrasonic assistance ensures that the coating layer is uniform and dense, while heat treatment promotes the interdiffusion of nickel and aluminum to form a metallurgical bonding interface. This step establishes a gradient transition zone from the metal matrix to the ceramic reinforcement. The plastic buffering effect of the nickel layer can effectively harmonize the mismatch of the thermal expansion coefficients of aluminum and silicon carbide, and inhibit the initiation of microcracks during sintering and cooling. Nickel can also improve the wettability of liquid phase sintering on silicon carbide, promote densification, and enhance the interfacial bonding strength. At the same time, the phosphorus element in the coating reacts with aluminum and cerium to generate a hard phosphide nanophase, which improves the hardness and wear resistance of the matrix through dispersion strengthening. In step S3 of the embodiment, rare earth cerium is introduced through a cerium nitrate-citric acid complexation reaction, and a hybrid coating layer is formed by ethylene glycol crosslinking. After calcination, it is transformed into nano-cerium oxide particles. Lanthanum oxide-assisted ball milling achieves rare earth mechanical doping and grain refinement. This step utilizes the special electronic structure of cerium and lanthanum to optimize grain boundary characteristics. Due to their large radius and strong activity, rare earth atoms preferentially segregate to polyaluminum grain boundaries, improving grain boundary bonding energy and fracture toughness. In terms of the overall performance of the composite material, the pinning effect of rare earth oxides at grain boundaries effectively inhibits the growth of sintered grains, and the grain refinement significantly improves yield strength and hardness. At the same time, the redox reversibility of cerium oxide can dynamically repair the oxide film on the wear surface, improving the wear resistance of the composite material.

[0089] From Table 1 and Figure 1-2It can be seen that the mechanical properties and corrosion resistance of the composite material prepared in Comparative Example 3 decreased. This is because commercially available silicon carbide powder replaced modified silicon carbide powder. In step a of the example, the silicon carbide surface was etched with fluorotitanic acid and titanium was introduced, which broke the inherent chemical inertness of silicon carbide and established anchoring sites for subsequent multiple coatings. For the composite material, the roughened ceramic surface significantly enhanced the mechanical interlocking strength with the aluminum matrix. The introduction of titanium improved the wettability of the molten metal to the ceramic phase at high temperatures, thereby reducing interfacial porosity and microcracks and improving hardness. At the same time, titanium oxide can form a transfer film during wear, reducing the coefficient of friction and improving the wear resistance of the composite material. In step b of the embodiment, the in-situ coating of aluminum-zirconium composite oxide onto the silicon carbide surface constructs a gradient ceramic transition layer. This layer acts as a thermal expansion buffer and a chemically active medium. Both alumina and zirconium oxide are high-hardness ceramic phases, and their synergistic coating significantly improves the load-bearing capacity and wear resistance of the reinforcement. Simultaneously, it mitigates the significant difference in thermal expansion coefficients between silicon carbide and aluminum alloy, suppressing interfacial debonding and radial cracking during sintering and cooling, thus optimizing the fracture toughness of the composite material. Furthermore, the dense oxide layer blocks the erosion path of corrosive media, improving the corrosion resistance of the composite material. In step c of the embodiment, the silica film formed by the hydrolysis and condensation of tetraethyl orthosilicate constitutes the final coating layer, endowing the silicon carbide surface with appropriate chemical reactivity and compatibility with sintering aids. The plastic deformation capacity of silica can absorb some energy during load transfer, improving the material's impact resistance. Simultaneously, the dense silica layer acts as a physical barrier, enhancing the composite material's resistance to pitting corrosion in electrolyte environments and improving its durability.

[0090] From Table 1 and Figure 1-2 It can be seen that the composite material prepared in Comparative Example 4 has the worst mechanical properties and corrosion resistance. This is because commercially available aluminum alloy powder replaced modified aluminum alloy powder, and commercially available silicon carbide powder replaced modified silicon carbide powder. The modified aluminum alloy and silicon carbide achieve synergistic reinforcement through surface modification. When the nickel layer and rare earth oxides of the aluminum alloy are sintered with the oxide coating layer of silicon carbide, a metallurgical bond is formed. Nickel improves melt wettability and fills ceramic grooves, while rare earth purifies grain boundaries and improves strength and toughness. Silicon carbide acts as a hard skeleton to bear the load, the nickel layer buffers deformation differences, and the hard phase strengthens the matrix, changing the wear mechanism from brittle fracture to micro-machining. In terms of hardness, silicon carbide provides basic support, while aluminum alloy achieves gradient distribution through fine grain strengthening. In terms of corrosion resistance, the silicon carbide oxide coating layer acts as a barrier, and the aluminum alloy molybdenum-tungsten oxide and rare earth passivation film constitute a second line of defense, synergistically blocking the corrosion path.

[0091] Although embodiments of this application have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of this application, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A composite material based on ceramics and aluminum alloys, characterized in that, The raw materials include the following parts by weight: 82-88 parts modified aluminum alloy powder, 12-18 parts modified silicon carbide powder, 0.35-0.45 parts composite sintering aid, and 0.2-0.3 parts dispersant; The modified aluminum alloy powder is prepared as follows: Step S1: Dissolve oxalic acid and phosphoric acid solutions in deionized water, then add aluminum alloy powder, react at 45-50℃ for 1-1.5h, and obtain product 1 after post-treatment; Step S2: Dissolve nickel sulfate, sodium hypophosphite, sodium citrate, sodium acetate, and ammonium bifluoride in deionized water in sequence, then adjust the pH to 9.2±0.1, add product 1, and react with ultrasound at 70-75℃ for 2.5-3 hours. After post-processing, obtain product 2. Step S3: Dissolve cerium nitrate hexahydrate, citric acid, and ethylene glycol in a mixed solvent, add product 2, react at 60-65℃ for 3-3.5h, adjust the pH to 6.2±0.1, then vacuum dry at 150-155℃ for 3-3.5h, keep warm at 495-505℃ for 1-1.5h, add lanthanum oxide and ball mill for 30-40min to obtain modified aluminum alloy powder.

2. The composite material based on ceramics and aluminum alloy according to claim 1, characterized in that, In step S1, the mass ratio of oxalic acid, aluminum alloy powder, and deionized water is 2.5-3.5:5:50-60, and the volume ratio of phosphoric acid solution and deionized water is 2.5-3.5:

200.

3. The composite material based on ceramics and aluminum alloy according to claim 1, characterized in that, The mass ratio of nickel sulfate, sodium hypophosphite, sodium citrate, sodium acetate, ammonium bifluoride, deionized water, and product 1 in step S2 is 0.95-1.05:7-8:10-11:5.5-6.5:0.8-1:290-310:

20.

4. The composite material based on ceramics and aluminum alloy according to claim 1, characterized in that, The mixed solvent mentioned in step S3 is prepared from anhydrous ethanol and deionized water in a volume ratio of 7:2.8-3.

2. The mass ratio of cerium nitrate hexahydrate, citric acid, ethylene glycol, product 2, and lanthanum oxide is 9.5-10.5:4.5-5.5:3-3.5:200:0.03-0.05, and the mass-volume ratio of product 2 to the mixed solvent is 1.5-2.5 g / 10 mL.

5. The composite material based on ceramics and aluminum alloy according to claim 1, characterized in that, The modified silicon carbide powder is prepared as follows: Step a: Add silicon carbide to an aqueous solution of fluorotitanic acid and react at 50-55°C for 1.5-2 hours. After post-treatment, product a is obtained. Step b: Dissolve aluminum nitrate and zirconium nitrate in deionized water in sequence, then adjust the pH value to 8.0±0.1, add product a, and reflux at 75-80℃ for 3-3.5h. After post-processing, product b is obtained. Step c: Add tetraethyl orthosilicate to the solvent, adjust the pH to 4.8±0.1, stir at room temperature for 2-2.5 h, add product b, ultrasonically disperse for 30-40 min, then adjust the pH to 8.5±0.1, and obtain modified silicon carbide powder after post-treatment.

6. The composite material based on ceramics and aluminum alloy according to claim 5, characterized in that, The mass-to-volume ratio of silicon carbide and fluorotitanic acid aqueous solution in step a is 0.95-1.05 g / 20 mL, and the mass percentage concentration of fluorotitanic acid aqueous solution is 8.5-9.5%.

7. The composite material based on ceramics and aluminum alloy according to claim 5, characterized in that, The mass ratio of aluminum nitrate, zirconium nitrate, product a, and deionized water in step b is 1.3-1.7:0.7-0.8:1.8-2.2:

30.

8. The composite material based on ceramics and aluminum alloy according to claim 5, characterized in that, In step c, the volume ratio of tetraethyl orthosilicate to solvent is 0.98-1.02:10, and the solvent is composed of anhydrous ethanol and deionized water in a volume ratio of 3.95-4.05:

1. The mass-volume ratio of product b to solvent is 1.95-2.05 g / 5 mL.

9. The composite material based on ceramics and aluminum alloy according to claim 1, characterized in that, The composite sintering aid is composed of magnesium oxide and trimethyl borate in a mass ratio of 1.9-2.1:1, and the dispersant is polyethylene glycol.

10. The method for preparing a composite material based on ceramics and aluminum alloys according to any one of claims 1-9, characterized in that, Includes the following steps: Modified aluminum alloy powder, modified silicon carbide powder, composite sintering aid, and dispersant are mixed, then shaped, degreased, and sintered to obtain the final product.

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