Aluminum alloy composite material with high strength and corrosion resistance and preparation method thereof

Abstract

The invention discloses an aluminum alloy composite material with high strength and corrosion resistance and a preparation method thereof, and relates to the technical field of aluminum alloy preparation. The aluminum alloy composite material is composed of an aluminum alloy base material and a reinforcement body, the reinforcement body is (Al6Zn2ZrNi) 100-x-yBxTiy alloy, x is larger than or equal to 3at.% and smaller than or equal to 4.2 at.%, y is larger than 6at.% and smaller than or equal to 8at.%, and y is larger than 6at.% and smaller than or equal to 8at. The aluminum alloy base material is Al-Mg-Si series aluminum alloy, and the adding amount of the reinforcement is 20-30% of the mass of the aluminum alloy base material. The (Al6Zn2ZrNi) 100-x-yBxTiy alloy prepared through spray deposition is adopted as a reinforcement body, aluminum alloy matrix components are smelted through certain charging steps, then die-casting forming, homogenization treatment and aging treatment are carried out, and the obtained aluminum alloy composite material has high hardness, strength and air tightness and is suitable for large-scale production. And the aluminum alloy has excellent corrosion resistance, wear resistance, high and low temperature resistance and processability, and is not prone to hot cracking in the die casting process.

Description

Technical Field

[0001] The present invention belongs to the technical field of aluminum alloy preparation, and particularly relates to an aluminum alloy composite material with high strength and corrosion resistance and a preparation method thereof. Background Art

[0002] In recent years, the requirements for aluminum alloy materials in various parts, equipment, and mechanical transmission devices such as aviation, high-speed rail, aircraft carriers, and automobiles have become increasingly stringent. They are required to have excellent properties such as light weight, high strength, high corrosion resistance, high temperature resistance, high hardness, high airtightness, and good workability. Currently, the performance of commonly used aluminum alloy materials is average and cannot achieve satisfactory use effects. At the same time, existing aluminum alloys are prone to corrosion in high-temperature, high-humidity, or corrosive environments (especially environments with relatively high Cl - content), and are prone to thermal cracking during the die-casting process, affecting the mechanical properties, durability, and application range of the materials.

[0003] Existing commercial aluminum alloy materials mainly include several commonly used aluminum alloy materials such as Al-Si series alloys, Al-Mg series alloys, Al-Cu series alloys, Al-Zn series alloys, and aluminum alloy composite materials (i.e., aluminum matrix composite materials added with reinforcements). The silicon content of Al-Si series alloys is generally 4-11wt%, which is light in weight, has excellent wear resistance, corrosion resistance, and high-temperature dimensional stability, and has excellent casting and machining performance. It is the most widely used type of casting aluminum alloy. However, its mechanical strength and elongation are relatively low, and its plasticity decreases with the increase of silicon content, resulting in cracks and pores, and difficult welding. The density of Al-Mg series alloys is low, and they have excellent mechanical properties, plasticity, corrosion resistance, and machining performance. However, their strength is low at high temperatures, and they are prone to stress corrosion cracking in specific environments, with complex surface treatment and high costs. The addition of Cu in Al-Cu series alloys can play a role in solid solution strengthening and precipitation hardening, making the aluminum-copper alloy have high mechanical strength, good heat resistance, and machining performance at the same time. However, its plasticity is low, corrosion resistance is poor, and stress corrosion cracking is prone to occur. Al-Zn series alloys do not form intermetallic compounds and have advantages such as high strength, light weight, and high temperature resistance. However, their corrosion resistance is poor, the tendency of thermal cracking during the casting process is obvious, plasticity is low, and if they are in a high-temperature state for a long time, their comprehensive performance will still decrease significantly. The most common aluminum alloy composite materials use ceramic particles as reinforcements to strengthen aluminum alloys, such as SiC, Al2O3, and SiO2 particles, etc. However, the wettability between the reinforcement phase and the aluminum alloy matrix is poor, which will lead to a sharp decrease in toughness and plasticity, and the reinforcement particles are prone to uneven distribution, forming agglomerates and crack sources, thereby causing problems such as poor ductility, low fracture toughness, and poor corrosion resistance in aluminum alloy composite materials.

[0004] Chinese Patent CN202410014901.X discloses an Al-Cu-Mn casting alloy with anti-thermal cracking performance and its preparation method. By adjusting the addition amount of trace elements and the melt treatment temperature, the microstructure and anti-thermal cracking performance of the aluminum alloy can be effectively controlled, and high-quality aluminum alloy castings with refined solidification structure and eliminated casting thermal cracks can be obtained. However, the Cu content is relatively high, and the Al2Cu(θ) phase formed by it and Al is prone to form a corrosion electric couple, that is, the corrosion resistance is poor. Chinese Patent CN202411544417.4 discloses a high-yield aluminum alloy material for die-casting heat treatment, and its formula includes: Si, Al, Fe, Mg, Zn, Ti, Zr and Sr. And after the molten solution is cast and formed, vacuum homogenization treatment and annealing treatment are carried out, which improves the corrosion resistance of the aluminum alloy sheet, and maintains the work hardening effect of the alloy, inhibits deformation and has the characteristics of high yield strength. However, the silicon content exceeds 6%, which will cause a tendency of thermal cracking during the die-casting process, and then reduce the mechanical strength and corrosion resistance of the aluminum alloy, and the long-term corrosion resistance effect is not ideal. Chinese Patent CN201810643219.1 discloses a self-lubricating aluminum alloy composite material, which uses aluminum alloy as the base material, and adds TiCoCrFeNiAl-coated MoS2 particles to the aluminum alloy. The aluminum-based composite material for drill pipes with self-lubrication is prepared by spray deposition additive manufacturing and hot extrusion process, which has excellent wear resistance and self-lubrication, and has a small friction coefficient and a long service life. However, MoS2 particles are added to the aluminum alloy composite material, which may reduce the strength and plasticity of the aluminum alloy, and are easy to agglomerate in the aluminum alloy, affecting the overall comprehensive performance. At the same time, MoS2 will reduce the corrosion resistance of the aluminum alloy, and then reduce the service life of the patented product. Summary of the Invention

[0005] The purpose of the present invention is to provide an aluminum alloy composite material with high strength and corrosion resistance. Through die-casting forming, it has high hardness and excellent mechanical properties, corrosion resistance, wear resistance, high and low temperature resistance, and processing performance, etc., improving the durability of aluminum alloy die-castings and expanding the application fields of aluminum alloy composite materials.

[0006] To achieve the purpose of the present invention, the present invention provides an aluminum alloy composite material with high strength and corrosion resistance, which is composed of an aluminum alloy base material and a reinforcing body. The reinforcing body is (Al6Zn2ZrNi) 100-x-y B x Ti y alloy, where 3 at.% ≤ x ≤ 4.2 at.%, 6 at.% < y ≤ 8 at.%;

[0007] The aluminum alloy base material is an Al-Mg-Si series aluminum alloy, and the addition amount of the reinforcing body is 20-30% of the mass of the aluminum alloy base material.

[0008] The reinforcement of the present invention is formed by spray deposition of a combination of elements of Al, Zn, Zr, Ni, B, and Ti in a certain atomic ratio. By designing a reasonable metal element and atomic ratio, due to the high-entropy effect and the characteristics of high-temperature spray air cooling, the formation of intermetallic compounds is prevented, and a single-phase solid solution is formed. The grains are fine and uniform, the structure is dense, the segregation of grain boundary elements is reduced, and the mechanical strength, high-temperature resistance, corrosion resistance, and thermal crack resistance of the aluminum alloy composite material of the present invention are significantly improved, and the durability and service life of the aluminum alloy composite material are improved. The synergistic refinement of grains by appropriate contents of B and Ti not only improves the wettability and interfacial compatibility between the reinforcement and the aluminum alloy matrix, but also improves the mechanical strength, thermal crack resistance, and high-temperature resistance of the present invention; when the B content is greater than 4.2 at.%, the corrosion resistance and toughness of the aluminum alloy are reduced, and when the B content is less than 3 at.%, the improvement effect of the mechanical strength and heat resistance of the aluminum alloy is not good; when the Ti content is greater than 8 at.%, the cost of the aluminum alloy composite material will increase, and the thermal crack resistance and toughness will be reduced. The addition of Zn, Zr, and Ni metal powders significantly improves the mechanical strength, corrosion resistance, high-temperature resistance, and thermal crack resistance of the present invention, and ensures that the present invention has excellent denseness, wear resistance, and thermal conductivity, and extends the service life of the aluminum alloy composite material of the present invention.

[0009] Further, in terms of mass percentage, the chemical composition of the Al-Mg-Si series aluminum alloy is: Mg 1.1-1.6%, Si 1.2-2.5%, Fe 0.3-0.6%, B 0.05-0.09%, Cr 1.4-1.8%, Mn 0.9-1.3%, Mo 0.15-0.32%, Nb 0.08-0.12%, and the balance is Al and unavoidable impurities.

[0010] The Mg component has a low density, and adding it to the aluminum alloy can reduce the overall density of the alloy. Mg is the main strengthening element in this aluminum alloy. Through homogenization treatment in the present invention, it is converted into a single-phase α solid solution, improving the strength, hardness, and corrosion resistance of the aluminum alloy. If the content of the Mg component is too high, there will be a risk of thermal cracks during the die-casting process, and the Mg content in the present invention is controlled at 1.1-1.6%.

[0011] The Si component can improve the processing fluidity and casting airtightness of the aluminum alloy, and has higher strength and hardness than pure aluminum (however, compared with other metals, its strength enhancement effect is not ideal). However, most of the silicon in the aluminum alloy coexists with aluminum in the form of a single-phase, and due to its semiconductor characteristics, that is, the higher the silicon content, the lower the thermal conductivity of the aluminum alloy. In the present invention, when the Si content exceeds 2.5%, the processability of the aluminum alloy is affected and the thermal conductivity is reduced; when the Si content is lower than 1.2%, it has a negative impact on the strength and corrosion resistance of the present invention.

[0012] The Fe component can reduce the tendency of the casting to stick to the mold, making it easier for the aluminum alloy to demold during die-casting. It can also improve the strength and hardness of the aluminum alloy. If the Fe content is too high, hard particles will be generated, and at the same time, the processing fluidity of the aluminum alloy will decrease, the tendency of hot cracking will increase, and both the mechanical properties and corrosion resistance will decrease. If the Fe content is too low, the demolding effect will be affected. In this invention, the Fe content is controlled at 0.3 - 0.6%.

[0013] The addition of the B component improves the wettability and interfacial compatibility between the aluminum alloy matrix and the reinforcement. It can combine with Al and Ti to form compounds such as TiB2 or AlB2, refine the grains, and improve the strength, toughness, high-temperature resistance, and thermal cracking resistance of the aluminum alloy matrix. However, it will have an impact on the corrosion resistance of the aluminum alloy. Therefore, in combination with the B content in the reinforcement, the B content in the aluminum alloy matrix of this invention is controlled at 0.05 - 0.09%.

[0014] The addition of the Cr component can refine the grains, dissolve into the aluminum alloy matrix to form a supersaturated solid solution, and improve the strength and corrosion resistance of the aluminum alloy matrix. In this invention, if the Cr content is lower than 1.4%, the strength and corrosion resistance of the aluminum alloy matrix will decrease. If the Cr content is higher than 1.8%, not only will the cost increase, but also the plasticity and toughness of the aluminum alloy matrix will decrease significantly, and the cast body is prone to cracking during die-casting.

[0015] The Mn component has the effects of solid solution strengthening and grain refinement, and can form the Al6(Mn,Fe) phase with iron (Fe), reducing the harmful FeAl3 phase, thereby improving the hardness, strength, toughness, heat resistance, and corrosion resistance of the aluminum alloy. However, if the Mn content is too high, it will form intermetallic compounds with Al, thereby reducing the plasticity and toughness, and will also affect the strength and corrosion resistance of the aluminum alloy matrix. In this invention, the Mn content is controlled at 0.9 - 1.3%.

[0016] The Mo component can improve the strength, heat resistance, and corrosion resistance of the aluminum alloy matrix. However, in this invention, when the Mo content is lower than 0.15%, it cannot improve the heat resistance and corrosion resistance of this invention, but instead increases the cost. If the Mo content is higher than 0.32%, it does not significantly improve the strength and corrosion resistance of this invention, and reduces the toughness, and the material cost increases.

[0017] The Nb component can refine the grains, improve the hardness and strength, high-temperature resistance, thermal cracking resistance, and corrosion resistance of the aluminum alloy matrix. In this invention, the Nb content is controlled at 0.08 - 0.12%, enabling this invention to improve its wear resistance, high-temperature resistance, thermal cracking resistance, and corrosion resistance while ensuring strength and hardness. If the Nb content is too high, the cost will be high, and it will affect its hardness, thermal cracking resistance, and corrosion resistance, and the wear resistance will decrease. If the Nb content is too low, the impact on the performance of the aluminum alloy matrix is not obvious.

[0018] Further, in the chemical composition of the Al-Mg-Si series aluminum alloy, the mass percentages of Mg and Si satisfy the condition: 2.8% ≤ Mg + Si ≤ 3.9%.

[0019] Mg + Si is a conventional component in the aluminum alloy and is a factor affecting hardness, strength, corrosion resistance, and processing fluidity in the present invention. It is limited to between 2.8% and 3.9% in the present invention. After the two are compounded, the enhancement effects on hardness, strength, airtightness, and processing fluidity are significant. Experiments have shown that when Mg + Si is less than 2.8%, the fluidity of the obtained aluminum alloy matrix decreases, the hardness and strength decrease, and the strength decreases, which also has a certain impact on the corrosion resistance; when Mg + Si is greater than 3.9%, it will cause a significant decrease in the plasticity and toughness of the aluminum alloy matrix, a decrease in corrosion resistance, and an increase in the risk of hot cracking tendency.

[0020] Further, in the chemical composition of the Al-Mg-Si series aluminum alloy, the mass percentages of Cr, Mn, and Mo satisfy the condition: 2.5% ≤ Cr + Mn + Mo ≤ 2.85%.

[0021] Cr + Mn + Mo is a factor affecting strength, corrosion resistance, and high-temperature resistance in the present invention. It is limited to between 2.5% and 2.85% in the present invention. On the one hand, the cost is reduced as much as possible, and on the other hand, after the three are compounded, the strength and corrosion resistance of the aluminum alloy matrix can be significantly improved, and its long-term use temperature can reach 300°C. Experiments have shown that when Cr + Mn + Mo is less than 2.5%, the corrosion resistance of the obtained aluminum alloy matrix is poor, the strength decreases, and the high-temperature resistance performance is significantly reduced; when Cr + Mn + Mo is greater than 2.85%, it will cause a significant decrease in the plasticity and toughness of the aluminum alloy matrix, and there is a tendency for the heat resistance and corrosion resistance to decrease.

[0022] The present invention also provides a preparation method for an aluminum alloy composite material with high strength and corrosion resistance, which specifically includes the following steps:

[0023] S1. Prepare the prefabricated reinforcement: Weigh the elemental powders of Al, Zn, Zr, Ni, B, and Ti in the (Al6Zn2ZrNi) 100-x-y B x Ti y alloy according to the atomic percentage, place them in a ball mill under an argon atmosphere for ball milling, vacuum dry to obtain a mixed powder; place the mixed powder in a melting furnace to heat and melt, then inject the melt into a metal liquid package, introduce high-pressure argon to atomize the metal liquid, and deposit it on the substrate through an atomizer to obtain (Al6Zn2ZrNi) 100-x-y B x Ti y alloy particles;

[0024] S2. Aluminum alloy batching: Weigh the raw materials according to the chemical composition of the Al-Mg-Si series aluminum alloy by mass percentage;

[0025] S3. Aluminum alloy melting: Add the above-mentioned weighed chemical components Si, Fe, B, Cr, Mn, Mo, Nb and Al into the melting furnace to melt, add a refining agent (the addition amount of the refining agent is 0.6% of the mass of the aluminum alloy matrix), keep it warm at 700 - 750 °C for 30 - 40 min, remove the surface scum to obtain the molten liquid A; then lower the temperature of the molten liquid A to 640 - 670 °C, add an aluminum-magnesium master alloy (add the aluminum-magnesium master alloy later to reduce the burning loss rate of magnesium), melt it, stir for 3 - 5 min to obtain the molten liquid B; then raise the temperature of the molten liquid B to 700 - 720 °C, add (Al6Zn2ZrNi) 100-x-y B x Ti y alloy particles, stir for 20 - 30 min, then add a refining agent (the addition amount of the refining agent is 0.2% of the mass of the aluminum alloy matrix), stir for 10 - 15 min, stand for 10 min, remove the surface scum to obtain the alloy liquid;

[0026] S4. Die casting: Pour the above alloy liquid into the required mold for die casting to obtain an aluminum alloy die-casting;

[0027] S5. Homogenization treatment: Place the above aluminum alloy die-casting in a vacuum heat treatment device for homogenization treatment, cool it to room temperature to obtain a homogenized casting;

[0028] S6. Aging treatment: Deburr and trim the above homogenized casting, and then perform aging treatment to obtain the aluminum alloy composite material of the required casting.

[0029] Furthermore, during the ball milling process in step S1, the ball-to-material ratio is 15:1, the rotation speed of the ball mill is 220 - 250 r / min, and the ball milling time is 3 - 4 h.

[0030] Furthermore, in step S3, the refining agent is composed of the following raw materials by mass percentage: 40 - 52 parts of NaCl, 30 - 40 parts of BaCL2, 15 - 23 parts of La2O3 and 3 - 5 parts of carbon powder.

[0031] Furthermore, in step S4, during the die casting process, the temperature of the poured alloy liquid is 670 - 680 °C, the injection pressure is 60 - 150 MPa, and the mold temperature is 200 - 300 °C.

[0032] Furthermore, in step S5, the temperature of the homogenization treatment is 430 - 450 °C, and the holding time is 3 - 8 h; the steps of the cooling treatment are: first water-cool the aluminum alloy die-casting to 200 - 250 °C, and then air-cool it to room temperature.

[0033] Further, in the step S6, the aging treatment steps are as follows: first, heat the homogenized casting to 120 - 130 °C and keep it warm for 24 - 36 h; then heat it to 180 - 190 °C and keep it warm for 30 - 45 min; cool it to 100 °C at a rate of 0.5 - 2 °C / min, and finally air-cool it to room temperature.

[0034] The present invention has achieved the following beneficial effects:

[0035] 1. The present invention uses the alloy (Al6Zn2ZrNi) 100-x-y B x Ti y prepared by spray deposition as the reinforcement, melts the aluminum alloy matrix components by a certain feeding step, and then obtains the aluminum alloy composite material through die-casting, homogenization treatment, and aging treatment. The obtained aluminum alloy composite material has high hardness, strength, and airtightness, and has excellent corrosion resistance, wear resistance, high and low temperature resistance, and processing performance, and is not prone to thermal cracking tendency during the die-casting process.

[0036] 2. According to the design concept of high-entropy alloys, the reinforcement of the present invention is composed of a combination of elements Al, Zn, Zr, Ni, B, and Ti in a certain atomic ratio, preventing the formation of intermetallic compounds and forming a single-phase solid solution, so that it has good wettability and interfacial compatibility with the aluminum alloy matrix during the die-casting process. Furthermore, the reinforcement can be evenly dispersed in the aluminum alloy matrix and can effectively combine with each metal element in the aluminum alloy matrix, refine the grains, greatly reduce the generation of pores, thereby significantly improving the airtightness, mechanical strength, high temperature resistance, corrosion resistance, and thermal crack resistance of the present invention, and extending the service life of the aluminum alloy composite material.

[0037] 3. During the melting process of the present invention, the refining agent is added in two times to enable the refining agent to fully react with impurities, significantly improving the purity and comprehensive performance of the aluminum alloy composite material. The refining agent of the present invention is composed of an appropriate proportion of NaCl, BaCL2, La2O3, and carbon powder, which can not only remove impurities in the aluminum alloy melt but also refine the grains, contribute to improving the hardness and strength of the aluminum alloy composite material, improve the processing fluidity of the aluminum alloy melt, reduce the generation of residual stress, and improve the toughness, wear resistance, and corrosion resistance of the present invention.

[0038] 4. Designed according to the chemical composition and structure of the aluminum alloy composite material, the present invention uses homogenization treatment and aging treatment for post-treatment of aluminum alloy die-castings, making the components in the present invention evenly distributed and preventing dislocation movement, improving the density, thereby improving the hardness, strength, and toughness of the present invention, and making it have good high-temperature stability and corrosion resistance, etc.

[0039] 5. The chemical composition and content of the aluminum alloy matrix of the present invention are designed by orthogonal experimental design. Most of the chemical components are common metals, which are easy to obtain, and have good wettability and interfacial compatibility with the reinforcement. As a result, the aluminum alloy matrix has high hardness, high strength, and excellent high-temperature impact resistance, wear resistance, corrosion resistance, etc. Detailed Embodiments

[0040] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0041] The high-strength and corrosion-resistant aluminum alloy composite material and its preparation method of the present invention will be described below with specific embodiments.

[0042] Embodiment 1

[0043] A preparation method of a high-strength and corrosion-resistant aluminum alloy composite material is as follows:

[0044] S1. Preparing the reinforcement: Weigh the elemental powders of Al, Zn, Zr, Ni, B, and Ti in the Al-Zn-Zr9Ni9B3Ti6 alloy by atomic percentage, place them in a ball mill under an argon atmosphere for ball milling. The ball-to-material ratio is 15:1, the rotation speed of the ball mill is 240 r / min, the ball milling time is 4 h, and then vacuum drying is carried out to obtain a mixed powder. The mixed powder is placed in a melting furnace and heated to melt, and then the molten liquid is poured into a metal liquid package. High-pressure argon gas at 0.75 MPa is introduced to atomize the metal liquid, and it is deposited on the substrate through an atomizer. The deposition distance is 1000 mm to obtain Al-Zn-Zr9Ni9B3Ti6 alloy particles. 55 Zn 18 Zr9Ni9B3Ti6 alloy particles. 55 Zn 18 Zr9Ni9B3Ti6 alloy particles.

[0045] S2. Aluminum alloy batching: Weigh the raw materials according to the chemical composition of the Al-Mg-Si series aluminum alloy by mass percentage: Al-Si12, Al-Mg10, Al-Fe10, Al-B10, Al-Cr10, Al-Mn20, Al-Mo5, Al-Nb20 master alloys and pure aluminum ingots. That is, the mass percentage of each metal element is: Mg 1.1%, Si 2.5%, Fe 0.6%, B 0.05%, Cr 1.4%, Mn 1.3%, Mo 0.15%, Nb 0.12%, impurities ≤ 0.01%, and the rest is Al.

[0046] S3. Melting of Aluminum Alloy: Add the weighed chemical components Si, Fe, B, Cr, Mn, Mo, Nb and Al into a melting furnace to melt, add 0.6 wt% refining agent (i.e., the addition amount of the refining agent is 0.6% of the total mass of the aluminum alloy chemical components), keep it warm at 720 °C for 40 min, remove the surface scum to obtain molten liquid A; then cool the temperature of molten liquid A to 650 °C, add Al-Mg10 master alloy, melt it, and stir for 5 min to obtain molten liquid B; then raise the temperature of molten liquid B to 720 °C, add Al 55 Zn 18 Zr9Ni9B3Ti6 alloy particles (Al 55 Zn 18 Zr9Ni9B3Ti6 alloy particles (the addition amount is 30% of the total mass of the Al-Mg-Si series aluminum alloy raw materials), stir for 30 min, then add 0.2 wt% refining agent (the addition amount of the refining agent is 0.2% of the total mass of the aluminum alloy chemical components), stir for 15 min, stand for 10 min, remove the surface scum to obtain alloy liquid.

[0047] S4. Die Casting: Heat the above alloy liquid to 680 °C, then pour it into the required mold for die casting, the injection pressure is 80 MPa, the injection speed is 2 m / s, and the mold temperature is 280 °C to obtain an aluminum alloy die casting.

[0048] S5. Homogenization Treatment: Place the above aluminum alloy die casting in a vacuum heat treatment device for homogenization treatment, the temperature is 440 °C, the holding time is 6 h, then water-cool the aluminum alloy die casting to 220 °C, and then air-cool it to room temperature to obtain a homogenized casting.

[0049] S6. Aging Treatment: Deburr and trim the above homogenized casting, then heat the homogenized casting to 120 °C and keep it warm for 36 h; then heat it to 180 °C and keep it warm for 45 min; cool it to 100 °C at a rate of 1 °C / min, and finally air-cool it to room temperature to obtain the aluminum alloy composite material of the required casting.

[0050] The above refining agent is composed of the following raw materials by mass percentage: 43 parts of NaCl, 35 parts of BaCL2, 18 parts of La2O3 and 4 parts of carbon powder.

[0051] Example 2

[0052] A preparation method of a high-strength and corrosion-resistant aluminum alloy composite material is as follows:

[0053] S1. Preparation of Preformed Reinforcement: Weigh Al by atomic percentage 52.7 Zn 17.5 Zr 8.8 Ni 8.8 B 4.2Elemental powders of Al, Zn, Zr, Ni, B and Ti in Ti8 alloy are placed in a ball mill under an argon atmosphere for ball milling. The ball-to-powder ratio is 15:1, the rotation speed of the ball mill is 240 r / min, the ball milling time is 4 h, and then it is dried in vacuum to obtain a mixed powder; the mixed powder is placed in a melting furnace to be heated and melted, and then the molten liquid is poured into a metal liquid package. High-pressure argon gas at 0.75 MPa is introduced to atomize the metal liquid, and it is deposited on the substrate through an atomizer. The deposition distance is 1000 mm to obtain Al 55 Zn 18 Zr9Ni9B3Ti6 alloy particles.

[0054] S2. Aluminum alloy batching: Weigh raw materials according to the chemical composition of the Al-Mg-Si series aluminum alloy by mass percentage: Al-Si12, Al-Mg10, Al-Fe10, Al-B10, Al-Cr10, Al-Mn20, Al-Mo5, Al-Nb20 master alloys and pure aluminum ingots. That is, the mass percentage of each metal element is: Mg 1.6%, Si 1.2%, Fe 0.3%, B 0.09%, Cr 1.8%, Mn 0.9%, Mo 0.15%, Nb 0.08%, impurities ≤ 0.01%, and the rest is Al.

[0055] S3. Aluminum alloy melting: Add the above-mentioned weighed chemical components Si, Fe, B, Cr, Mn, Mo, Nb and Al into the melting furnace to be melted, add 0.6 wt% refining agent (that is, the addition amount of the refining agent is 0.6% of the total mass of the aluminum alloy chemical components), keep it warm at 750 °C for 30 min, and remove the surface scum to obtain molten liquid A; then lower the temperature of molten liquid A to 660 °C, add Al-Mg10 master alloy, melt it, and stir for 5 min to obtain molten liquid B; then raise the temperature of molten liquid B to 720 °C, add Al 55 Zn 18 Zr9Ni9B3Ti6 alloy particles (the addition amount of Al 55 Zn 18 Zr9Ni9B3Ti6 alloy particles is 20% of the total mass of the Al-Mg-Si series aluminum alloy raw materials), stir for 30 min, then add 0.2 wt% refining agent (the addition amount of the refining agent is 0.2% of the total mass of the aluminum alloy chemical components), stir for 15 min, stand for 10 min, and remove the surface scum to obtain alloy liquid.

[0056] S4. Die casting: Heat the above alloy liquid to 680 °C, and then pour it into the required mold for die casting. The injection pressure is 80 MPa, the injection speed is 2 m / s, and the mold temperature is 280 °C to obtain an aluminum alloy die casting.

[0057] S5. Homogenization treatment: Place the above aluminum alloy die-casting parts in a vacuum heat treatment device for homogenization treatment at a temperature of 435 °C for 7 hours, then water-cool the aluminum alloy die-casting to 210 °C and then air-cool to room temperature to obtain homogenized castings.

[0058] S6. Aging treatment: Deburr and trim the above homogenized castings, then heat the homogenized castings to 130 °C and hold for 24 hours; then heat to 190 °C and hold for 30 minutes; cool to 100 °C at a rate of 2 °C / min and finally air-cool to room temperature to obtain the aluminum alloy composite material of the required castings.

[0059] The above refining agent is the same as that in Example 1, and specifically refer to Example 1.

[0060] Example 3

[0061] The preparation method of a high-strength and corrosion-resistant aluminum alloy composite material is the same as that in Example 1, and the chemical composition, content and addition method of the refining agent are also the same. Specifically refer to Example 1.

[0062] The difference is that, weighed by atomic percentage, the reinforcing body in this Example 3 is Al 54 Zn 18 Zr9Ni9B 3.5 Ti 6.5 alloy particles, and the addition amount of the reinforcing body is 26.5% of the total mass of the Al-Mg-Si series aluminum alloy raw materials.

[0063] Weighed by mass percentage, the chemical composition of the Al-Mg-Si series aluminum alloy (i.e., the aluminum alloy matrix) is: Mg 1.6%, Si 2.3%, Fe 0.5%, B 0.07%, Cr 1.4%, Mn 0.9%, Mo 0.32%, Nb 0.1%, impurities ≤ 0.01%, and the rest is Al.

[0064] Example 4

[0065] The preparation method of a high-strength and corrosion-resistant aluminum alloy composite material is the same as that in Example 1, and the chemical composition, content and addition method of the refining agent are also the same. Specifically refer to Example 1.

[0066] The difference is that, weighed by atomic percentage, the reinforcing body in this Example 4 is Al 53.4 Zn 17.8 Zr 8.9 Ni 8.9 B4Ti7 alloy particles, and the addition amount of the reinforcing body is 24% of the total mass of the Al-Mg-Si series aluminum alloy raw materials.

[0067] Weigh by mass percentage. The chemical composition of the Al-Mg-Si series aluminum alloy (i.e., the aluminum alloy matrix) is as follows: Mg 1.4%, Si 1.8%, Fe 0.5%, B 0.07%, Cr 1.45%, Mn 1.0%, Mo 0.2%, Nb 0.1%, impurities ≤ 0.01%, and the rest is Al.

[0068] Example 5

[0069] The preparation method of a high-strength and corrosion-resistant aluminum alloy composite material is the same as that of Example 4, and specifically refer to Example 4. The difference is that in step S3 of this Example 5, the melting of the aluminum alloy is as follows: The above-mentioned weighed chemical components Mg, Si, Fe, B, Cr, Mn, Mo, Nb, and Al 53.4 Zn 17.8 Zr 8.9 Ni 8.9 B4Ti7 alloy particles (i.e., the addition amount of the reinforcement is still 24% of the total mass of the Al-Mg-Si series aluminum alloy raw materials) are added to the melting furnace to be melted, and 0.8 wt% of the refining agent (i.e., the addition amount of the refining agent is 0.8% of the total mass of the aluminum alloy chemical components) is added. It is kept warm at 750 °C for 60 min, static for 10 min, and the surface scum is removed to obtain the alloy liquid.

[0070] Comparative Example 1

[0071] The preparation method of a high-strength and corrosion-resistant aluminum alloy composite material is the same as that of Example 4, and specifically refer to Example 4. The difference is that in this Comparative Example 1, instead of adding the reinforcement to the Al-Mg-Si series aluminum alloy for modification, the elemental powders of Al, Zn, Zr, Ni, B, and Ti contained in the reinforcement are added to the Al-Mg-Si series aluminum alloy according to the atomic percentage of 53.4 Zn 17.8 Zr 8.9 Ni 8.9 the B4Ti7 alloy particles, converted into mass percentage, and prepared according to the preparation method of Example 4 (i.e., step S1 is cancelled, and these metal elemental powders are directly added in the feeding order).

[0072] Comparative Example 2

[0073] The preparation method of a high-strength and corrosion-resistant aluminum alloy composite material is the same as that of Example 4, and specifically refer to Example 4. The difference is that in this Comparative Example 2, the chemical composition of the Al-Mg-Si series aluminum alloy (i.e., the aluminum alloy matrix) by mass percentage is as follows: Mg 1.6%, Si 2.5%, Fe 0.5%, B 0.07%, Cr 1.8%, Mn 1.3%, Mo 0.32%, Nb 0.1%, impurities ≤ 0.01%, and the rest is Al.

[0074] Comparative Example 3

[0075] The preparation method of an aluminum alloy composite material with high strength and corrosion resistance is the same as that of Example 4, and specifically refer to Example 4. The difference is that the chemical composition of the Al-Mg-Si series aluminum alloy (i.e., the aluminum alloy matrix) in this Comparative Example 3 by mass percentage is: Mg 1.1%, Si 2.2%, Fe 0.5%, B 0.07%, Cr 1.4%, Mn 0.9%, Mo 0.15%, Nb 0.1%, impurities ≤ 0.01%, and the rest is Al.

[0076] Comparative Example 4

[0077] The preparation method of an aluminum alloy composite material with high strength and corrosion resistance is the same as that of Example 4, and specifically refer to Example 4. The difference is that the refining agent in this Comparative Example 4 is composed of NaCl, KCl and CaF2 with a mass ratio of 3:6:1.

[0078] Comparative Example 5

[0079] The preparation method of an aluminum alloy composite material with high strength and corrosion resistance is the same as that of Example 4, and specifically refer to Example 4. The difference is that the aging treatment in this Comparative Example 5 adopts a conventional method, that is, heat preservation at 180 °C for 5 h, and then air cooling to room temperature.

[0080] Comparative Example 6

[0081] The preparation method of the aluminum alloy in this Comparative Example 6 is the same as that of Example 4. Different from it, no reinforcing body (i.e., no addition of Al 53.4 Zn 17.8 Zr 8.9 Ni 8.9 B4Ti7 alloy particles) is added, and the reinforcing body addition steps in steps S1 and S2 are not included (i.e., the addition of Al 53.4 Zn 17.8 Zr 8.9 Ni 8.9 B4Ti7 alloy particles are deleted).

[0082] The aluminum alloy composite materials prepared in the above Examples 1-5 and Comparative Examples 1-6 are subjected to tests on mechanical properties, wear resistance, corrosion resistance and heat resistance, and the test results are shown in Table 1 and Table 2 below.

[0083] Table 1 Mechanical Property Test Results Table

[0084]

[0085] From the test results in Table 1, it shows that the present invention has excellent mechanical strength and fracture toughness, and can still ensure excellent toughness and mechanical strength at 300 °C. The reinforcing body (Al6Zn2ZrNi) 100-x-y Bx Ti y After adding the Ti alloy to the aluminum alloy matrix, the strength, toughness, and high-temperature resistance of the aluminum alloy composite material are improved; when improving the aluminum alloy matrix composition, the refining agent composition, and the heat treatment process, the mechanical strength, toughness, and high-temperature resistance of the present invention are all improved to a certain extent.

[0086] Table 2 Performance test results of the aluminum alloy composite material

[0087] <![CDATA[Wear rate × 10 -6 mm 3 / Nm]]> <![CDATA[Corrosion rate g / m 2 ·h]]> Hardness HV Example 1 <![CDATA[6.7×10 -6 > 0.0701 189 Example 2 <![CDATA[5.6×10 -6 > 0.0693 195 Example 3 <![CDATA[6.5×10 -6 > 0.0685 201 Example 4 <![CDATA[7.2×10 -6 > 0.0636 208 Example 5 <![CDATA[5.3×10 -6 > 0.0793 184 Comparative Example 1 <![CDATA[9.6×10 -5 > 0.102 125 Comparative Example 2 <![CDATA[6.8×10 -6 > 0.0869 196 Comparative Example 3 <![CDATA[6.3×10 -6 > 0.0824 182 Comparative Example 4 <![CDATA[6.6×10 -6 > 0.0725 192 Comparative Example 5 <![CDATA[6.5×10 -6 > 0.0894 175 Comparative Example 6 <![CDATA[8.5×10 -5 > 0.231 106

[0088] Note: The above corrosion rate test is carried out in a salt spray environment, and the reagent for the salt spray is a 50 g / L sodium chloride solution.

[0089] The test results in Table 2 show that the present invention has excellent corrosion resistance and wear resistance. The reinforcing body (Al6Zn2ZrNi) 100-x-y B x Ti y After adding the B-Ti alloy to the aluminum alloy matrix, the hardness, corrosion resistance, and wear resistance of the aluminum alloy composite material are improved; when improving the aluminum alloy matrix composition, the refining agent composition, and the heat treatment process, the hardness, corrosion resistance, and wear resistance of the present invention are all improved to a certain extent.

[0090] The technical features of the above-described embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope described in this specification.

[0091] The above-described embodiments only represent several implementation manners of the present invention, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the present invention patent. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several deformations and improvements can still be made, and these all belong to the protection scope of the present invention.

Claims

1. An aluminum alloy composite material with high corrosion resistance is composed of an aluminum alloy base material and a reinforcing body, characterized in that, The reinforcement is (Al6Zn2ZrNi) 100-x-y B x Ti y alloy, where 3 at.% ≤ x ≤ 4.2 at.%, 6 at.% < y ≤ 8 at.%; The aluminum alloy substrate is an Al-Mg-Si series aluminum alloy, and the addition amount of the reinforcing body is 20-30% of the mass of the aluminum alloy substrate.

2. The aluminum alloy composite material with high strength and corrosion resistance according to claim 1, wherein In terms of mass percentage, the chemical composition of the Al-Mg-Si series aluminum alloy is: Mg 1.1-1.6%, Si 1.2-2.5%, Fe 0.3-0.6%, B 0.05-0.09%, Cr 1.4-1.8%, Mn 0.9-1.3%, Mo 0.15-0.32%, Nb 0.08-0.12%, and the rest is Al and inevitable impurities.

3. The aluminum alloy composite material with high strength and corrosion resistance according to claim 2, characterized in that In the chemical composition of the Al-Mg-Si series aluminum alloy, the mass percentages of Mg and Si satisfy the condition: 2.8% ≤ Mg + Si ≤ 3.9%.

4. The aluminum alloy composite material with high strength and corrosion resistance according to claim 2, characterized in that, In the chemical composition of the Al-Mg-Si series aluminum alloy, the mass percentages of Cr, Mn and Mo satisfy the condition: 2.5% ≤ Cr + Mn + Mo ≤ 2.85%.

5. A method for preparing an aluminum alloy composite material with high corrosion resistance as described in any one of claims 1-4, characterized in that, Specifically, it includes the following steps: S1. Preparing the reinforcing body: Weigh the elemental powders of Al, Zn, Zr, Ni, B, and Ti in the (Al6Zn2ZrNi) alloy by atomic percentage, place them in a ball mill under an argon atmosphere for ball milling, and then vacuum dry to obtain a mixed powder. Place the mixed powder in a melting furnace to heat and melt it, then inject the molten liquid into a metal ladle, introduce high-pressure argon to atomize the metal liquid, and deposit it onto a substrate through an atomizer to obtain (Al6Zn2ZrNi) 100-x-y B x Ti y alloy particles; 100-x-y B x Ti y alloy particles; S2. Aluminum alloy batching: Weigh raw materials according to the chemical composition of the Al-Mg-Si series aluminum alloy by mass percentage; S3. Aluminum alloy melting: Add the weighed chemical components Si, Fe, B, Cr, Mn, Mo, Nb, and Al into a melting furnace to melt. Add a refining agent, keep it warm at 700 - 750 °C for 30 - 40 min, remove the surface dross, and obtain the molten liquid A. Subsequently, lower the temperature of the molten liquid A to 640 - 670 °C, add an aluminum-magnesium master alloy, melt it, and stir for 3 - 5 min to obtain the molten liquid B. Then raise the temperature of the molten liquid B to 700 - 720 °C, add (Al6Zn2ZrNi) 100-x-y B x Ti y alloy particles, stir for 20 - 30 min, then add a refining agent, stir for 10 - 15 min, let it stand for 10 min, remove the surface dross, and obtain the alloy liquid; S4. Die casting: Pour the above alloy liquid into the required mold for die casting to obtain an aluminum alloy die casting; S5. Homogenization treatment: Place the above aluminum alloy die casting in a vacuum heat treatment device for homogenization treatment, and cool it to room temperature to obtain a homogenized casting; S6. Aging treatment: Deburr and trim the above homogenized casting, and then perform aging treatment to obtain the aluminum alloy composite material of the required casting.

6. The preparation method of the aluminum alloy composite material with high corrosion resistance according to claim 5, characterized in that, During the ball milling process in step S1, the ball-to-material ratio is 15:1, the rotation speed of the ball mill is 220-250 r / min, and the ball milling time is 3-4 h.

7. The preparation method of the aluminum alloy composite material with high corrosion resistance according to claim 5, characterized in that, In step S3, the refining agent is composed of the following raw materials by mass percentage: 40-52 parts of NaCl, 30-40 parts of BaCL2, 15-23 parts of La2O3 and 3-5 parts of carbon powder.

8. The preparation method of the aluminum alloy composite material with high strength and corrosion resistance according to claim 5, characterized in that, In step S4, during the die casting process, the temperature of the poured alloy liquid is 670-680 °C, the injection pressure is 60-150 MPa, and the mold temperature is 200-300 °C.

9. The preparation method of the aluminum alloy composite material with high strength and corrosion resistance according to claim 5, characterized in that, In step S5, the temperature of the homogenization treatment is 430-450 °C, and the holding time is 3-8 h; the steps of the cooling treatment are: first water-cool the aluminum alloy die casting to 200-250 °C, and then air-cool it to room temperature.

10. The preparation method of the aluminum alloy composite material with high strength and corrosion resistance according to claim 5, characterized in that, In step S6, the steps of the aging treatment are: first heat the homogenized casting to 120-130 °C and hold for 24-36 h; then heat it to 180-190 °C and hold for 30-45 min; cool it to 100 °C at 0.5-2 °C / min, and finally air-cool it to room temperature.

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