High-strength and high-wear-resistance cast aluminum alloy material and preparation method thereof

Abstract

The invention discloses a high-strength and high-wear-resistance cast aluminum alloy material and a preparation method thereof, and belongs to the technical field of motors for new energy automobiles. The cast aluminum alloy material is prepared from the following components in parts by weight: 0.2 to 0.5 weight percent of Si, 0.7 to 1.0 weight percent of Cu, 0.2 to 0.5 weight percent of IIA group elements and the balance of Al and inevitable impurities. The cast aluminum alloy material can reduce the alloy cracking tendency in the casting process, so that the yield strength and the tensile strength of a cast aluminum rotor made of the alloy material are improved, the cast aluminum rotor can stably run when running at the high rotating speed of 23000 rpm or above, and the running safety of the cast aluminum rotor is improved.

Description

Technical Field

[0001] This application relates to a high-strength, high-wear-resistant cast aluminum alloy material and its preparation method, belonging to the field of motor technology for new energy vehicles. Background Technology

[0002] Aluminum alloys, with their advantages of high strength, low cost, and high recyclability, are gradually replacing copper alloys as the main material for automotive motor rotors. Currently, common rotor manufacturing methods include centrifugal casting and high-pressure casting, with centrifugal casting being widely used due to its lower porosity and higher material density.

[0003] The rapid development of new energy vehicles has placed higher demands on the power and efficiency of automotive motors. Motor rotors commonly generate heat, and prolonged operation at high temperatures and speeds exceeding 23,000 rpm can lead to low-cycle fatigue and creep losses, potentially causing safety accidents. Therefore, cast aluminum rotor materials need to possess excellent high-temperature heat resistance and creep resistance, while also exhibiting superior electrical conductivity and mechanical properties.

[0004] To obtain high-strength, high-temperature-resistant, and high-wear-resistant cast aluminum alloy materials, it is necessary to improve the alloying properties of various elements in the aluminum alloy. Existing technologies, such as the Chinese patent CN119287225B, disclose an aluminum alloy material for a high-speed asynchronous motor cast aluminum rotor and its preparation method. This involves designing the combinations of elements Mg, Si, Ca, B, Mn, Ti, V, Cr, Cu, and Ni, and combining them with specific heat treatment processes. By controlling the precipitation and solidification of the second-phase Mg2Si, Al2CuNi, Al3Fe, and AlNi components at appropriate temperatures and times, the solid solubility in the aluminum matrix is ​​reduced, thus increasing the yield strength. However, the aforementioned patent achieves the performance improvement of the cast aluminum rotor by adding multiple elements. This approach not only increases the production cost of the cast aluminum rotor but also leads to uneven dispersion of numerous elements during preparation, resulting in product quality variations and reduced consistency. Furthermore, the melting time and temperature of various elements differ, and their addition to the molten aluminum can cause incomplete melting of some elements, further affecting the quality of the cast aluminum rotor product.

[0005] Therefore, there is an urgent need for a cast aluminum alloy material that can operate stably at speeds above 23,000 rpm and has high strength and wear resistance. Summary of the Invention

[0006] To address the aforementioned issues, a high-strength and high-wear-resistant cast aluminum alloy material is provided. This material not only possesses high strength and creep resistance but also exhibits strong wear resistance. Under operating conditions of high temperature and speeds exceeding 23,000 rpm, it can maintain operational stability and extend the service life of the cast aluminum rotor.

[0007] This application provides a high-strength and high-wear-resistant cast aluminum alloy material, which, by weight, comprises Si: 0.2-0.5wt%, Cu: 0.7-1.0wt%, Group IIA elements: 0.2-0.5wt%, with the remainder being Al and unavoidable impurities.

[0008] The addition of Si to the cast aluminum alloy material in this application serves several purposes: first, it improves the high-temperature fluidity of the alloy, making it easier for molten aluminum to fill the mold cavity, thus facilitating the manufacture of rotors with complex shapes; second, it reduces shrinkage, lowers the tendency for hot cracking, and improves the dimensional accuracy and quality of the castings; and third, it can form a hard silicon phase with Al, which can significantly improve the wear resistance of the cast aluminum rotor and extend its service life.

[0009] Adding Cu allows it to form intermetallic compounds such as θ'-(Al2Cu) with Al, significantly increasing the alloy's strength. These intermetallic compounds also maintain good stability at high temperatures, thus improving the heat resistance of the cast aluminum alloy and enabling it to operate in high-temperature environments, ensuring the operational stability and safety of the cast aluminum rotor.

[0010] Adding Group IIA elements can strengthen the matrix. For example, Mg in Group IIA can form the Mg2Si phase with Al, which can improve the strength and conductivity of the alloy, significantly improve the high-temperature creep resistance of the alloy, and also improve the strength and casting performance of the alloy.

[0011] Optionally, the weight ratio of Si, Cu and Group IIA elements is (1.2-1.4):(2.0-2.4):1.

[0012] At the aforementioned ratios, Si, Cu, and Group IIA elements synergistically enhance the stability of aluminum alloys, thereby improving their strength, creep resistance, and wear resistance. Specifically, the addition of Si improves the alloy's casting properties; silicon and aluminum form a solid solution, enhancing the alloy's high-temperature moldability, reducing shrinkage, and eliminating hot cracking tendency. Cu increases the alloy's fluidity, facilitating the casting process and promoting the formation of cast aluminum rotors. The addition of Group IIA elements, such as Mg, primarily forms the Mg₂Si strengthening phase with Si, significantly refining the as-cast microstructure and increasing the alloy's strength.

[0013] If a large amount of Si is added, a large number of coarse primary Si phases will be generated in the alloy system. During solidification, large blocky or needle-shaped primary Si will precipitate. These hard and brittle phases are prone to becoming stress concentration points, which will increase the brittleness of the cast aluminum rotor and thus increase the probability of crack formation.

[0014] If a large amount of Cu is added, the unbonded free Cu will form microcouples inside the alloy, accelerating the electrochemical corrosion process. This will cause problems such as pitting corrosion and intergranular corrosion in the cast aluminum rotor in humid or corrosive environments, significantly shortening its service life. At the same time, excess Cu will precipitate a large number of coarse Al2Cu phases at grain boundaries and within the grains. These phases are highly brittle and will become stress concentration points, leading to a significant decrease in the elongation and impact toughness of the alloy. This will make the cast aluminum rotor more prone to cracking or fracture when subjected to vibration, impact, or thermal stress, affecting the safe operation of the motor.

[0015] Adding a large amount of Group IIA elements, such as Mg, will significantly increase the casting difficulty of the alloy, leading to more production defects, expanding the solidification temperature range of the alloy, and increasing the probability of internal pore defects such as shrinkage cavities and porosity in the casting. Higher casting pressure or more complex processes are required to improve this.

[0016] Optionally, the group IIA element is selected from at least one of Mg, Ca, and Be.

[0017] Mg can dissolve in the α-Al matrix, causing lattice distortion and hindering dislocation movement, thereby improving the strength and hardness of the alloy; Ca can promote the nucleation of the α-Al phase during alloy solidification, thus refining the grains; it can also change the morphology of eutectic silicon from coarse needle-like flakes to fine fibrous or granular forms, thereby enhancing the strength and toughness of the alloy; Be can form a dense oxide film on the surface of molten aluminum during the melting and casting process, thereby reducing the oxidation of molten aluminum and improving the purity and quality of the material.

[0018] Optionally, the Group IIA elements include Mg and Ca in a weight ratio of 1:(0.6-1.0).

[0019] At the above ratio, Mg and Ca can play an effective synergistic role, hindering dislocation movement, refining the particles in the alloy, forming a stable crystal structure, improving heat resistance and high-temperature dimensional stability, and also possessing excellent mechanical and electrical properties.

[0020] Optionally, the Group IIA elements include Mg, Ca, and Be in a weight ratio of 1:(0.6-1.0):(0.1-0.2).

[0021] At the above ratio, the introduction of Be element, through the synergistic refinement of particles in the alloy by Mg and Ca, can reduce segregation nodules and decrease the thickness of the segregation layer structure of the alloy.

[0022] Another aspect of this application provides a method for preparing a high-strength, high-wear-resistant cast aluminum alloy material, comprising the following steps: S1: Pre-treat the Al raw material to obtain the pre-treated Al raw material; S2: Place the Al raw material into the melting furnace, heat it to 710-730℃, add the weighed Si and Cu elements, stir evenly after dissolving completely, add the refining agent for the first refining, keep it at the temperature for 10-15 minutes, let it stand and remove the slag to obtain intermediate liquid A. S3: Heat intermediate liquid A to 720-730℃, add the weighed Group VIII element, add the refining agent again for a second refining, keep warm for 20-30 minutes, let stand and remove the slag to obtain intermediate liquid B; S4: Preheat the casting mold, then cool the intermediate liquid B to 120°C and pour it into the casting mold for centrifugation. After the alloy material solidifies, the casting equipment stops rotating and cools naturally for 60-90 seconds. Then, air cool to room temperature to obtain the casting. S5: The casting is heat-treated and then naturally cooled to room temperature to obtain the final product.

[0023] Optionally, the pretreatment includes immersing the Al raw material in a 5-8 times volume of oxalic acid solution for 20-30 minutes, followed by drying to obtain the pretreated Al raw material.

[0024] Soaking Al raw materials in oxalic acid has several advantages. First, oxalic acid reacts with and removes some impurities in the Al raw materials, reducing their impact on the smelting process and product quality. Second, it helps remove the oxide film on the surface, increasing the bonding force between alloying elements and the Al matrix during subsequent smelting, resulting in a more uniform alloy composition. Third, it allows for faster and more uniform melting, reducing smelting time and energy consumption, and improving production efficiency. Fourth, during the smelting process, the oxalic acid on the surface of the Al raw materials decomposes at high temperatures to generate CO gas. CO readily undergoes a redox reaction with active hydrogen, thus efficiently removing active hydrogen from the high-temperature molten aluminum.

[0025] Optionally, the centrifugation speed in step S4 is 150-200 r / min, and the centrifugation time is 50-60 s.

[0026] Optionally, in the casting mold, the temperature of the upper mold is 590-620℃, and the temperature of the lower mold is 390-400℃.

[0027] Optionally, during the first refining, the rate of spraying the refining agent is controlled at 0.8-1.0 kg / min.

[0028] Optionally, during the second refining process, the rate of spraying the refining agent is controlled to be 0.4-0.6 kg / min.

[0029] Controlling the injection speed of the refining agent can promote the uniformity of the reaction between the refining agent and the molten aluminum. This allows the refining agent to be evenly dispersed in the molten aluminum as fine particles, maximizing the contact interface between the refining agent and the molten aluminum. This accelerates the core refining reactions such as desulfurization, dephosphorization, and deoxidation, thereby improving the quality and refining efficiency of cast aluminum alloy materials. If the injection speed is too fast, the refining agent is prone to agglomerate on the surface of the molten aluminum, and some of the refining agent cannot be integrated into the interior of the molten aluminum in time, only reacting locally on the surface, resulting in incomplete reaction. Conversely, if the speed is too slow, the diffusion range of the refining agent in the molten aluminum is limited, the overall reaction rate is significantly reduced, and the refining process time is prolonged, reducing product production efficiency.

[0030] Optionally, the refining agent, by weight fraction, comprises: 30-40 parts modified graphene, 10-20 parts cerium chloride, and 5-10 parts oxalate.

[0031] Optionally, oxalates include at least one of sodium oxalate and potassium oxalate.

[0032] The addition of modified graphene, cerium chloride, and oxalate can improve refining efficiency. Modified graphene can adsorb impurities and hydrogen atoms, while cerium chloride removes oxides and simultaneously refines grain size and improves conductivity without the need for additional grain refiners. Oxalate decomposes into CO at high temperatures, which reacts with hydrogen to effectively remove hydrogen. Through the synergistic effect of these three components, refining efficiency and quality can be effectively improved, thereby enhancing the various performance characteristics of the cast aluminum rotor.

[0033] Optionally, the preparation method of the modified graphene includes the following steps: S10: Graphene is oxidized in a hydrogen peroxide solution to obtain pretreated graphene; S20: Under inert gas protection, pretreated graphene is added with perfluorooctyltrichlorosilane and an acid-binding agent and reacted at 50-70℃ for 1-2 hours. After filtration and drying, modified graphene is obtained.

[0034] After graphene is oxidized with hydrogen peroxide solution, it contains a large number of hydroxyl groups. After the hydroxyl groups react with perfluorooctyltrichlorosilane, perfluorooctyl and chlorosilane groups are introduced into the surface of graphene. During the refining process, graphene has a large specific surface area and can adsorb tiny impurities. The introduced fluorine and chlorine elements can react with Al2O3 to produce AlF3 and AlCl3. AlCl3 volatilizes at high temperature, and AlF3 becomes liquid at high temperature, separating from the aluminum liquid. This is then processed by slag removal.

[0035] Optionally, the weight ratio of the graphene to the hydrogen peroxide solution is 1:(4-6).

[0036] Optionally, the weight ratio of graphene to perfluorooctyltrichlorosilane is 1:(0.8-1).

[0037] Optionally, the heat treatment process in step S5 is as follows: S100: Heat the casting to 320-340℃ at a heating rate of 10-15℃ / min and hold for 2-4 hours. Then heat to 360-400℃ at a heating rate of 10-20℃ and hold for 1-2 hours. Then cool to 340-350℃ at a cooling rate of 10-15℃ and hold for 1-2 hours. S200: The heat-insulated cast aluminum alloy material is placed in a coolant to cool to room temperature. The coolant contains 15-20wt% control agent and the remainder is water. The cooling rate of the coolant is 40-60℃ / s. S300: Heat to 160-170℃ at a heating rate of 10℃ / min and hold for 4 hours.

[0038] Optionally, the control agent is selected from polymethyl methacrylate, sodium alginate and hydroxyethyl cellulose in a weight ratio of 7:4:2.

[0039] Optionally, the molecular weight of polymethyl methacrylate is 15,000-25,000, the molecular weight of sodium alginate is 300,000-400,000, and the molecular weight of hydroxyethyl cellulose is 150,000-200,000.

[0040] The beneficial effects of this application include, but are not limited to: 1. The high-strength and high-wear-resistant cast aluminum alloy material of this application, by adding S, Cu and Group IIA elements, can stabilize the boundary structure, prevent grain boundary slip, effectively improve the strength and hardness of the cast aluminum rotor, reduce creep, and at the same time improve the wear resistance of the cast aluminum rotor.

[0041] 2. The high-strength and high-wear-resistant cast aluminum alloy material of this application reduces the tendency of alloy cracking during the casting process through the combination of various elements, thereby improving the yield strength and tensile strength of the cast aluminum rotor and increasing the yield rate of the cast aluminum rotor in production.

[0042] 3. The high-strength and high-wear-resistant cast aluminum alloy material according to this application can exhibit stable operation at high speeds of 23,000 rpm and above, thereby improving the operational safety of the cast aluminum rotor and extending its service life at high speeds. Detailed Implementation

[0043] The present application is described in detail below with reference to the embodiments, but the present application is not limited to these embodiments.

[0044] Unless otherwise specified, the raw materials used in the embodiments and comparative examples of this application were all purchased commercially.

[0045] Unless otherwise specified, the methods used in the embodiments and comparative examples of this application are conventional methods in the prior art. The control agents used in the following embodiments and comparative examples are all commercially available products.

[0046] The acid-binding agent in this application is at least one of potassium carbonate, ammonium carbonate, and sodium carbonate.

[0047] Example 1 This embodiment relates to a high-strength and high-wear-resistant cast aluminum alloy material, which, by weight, includes Si: 0.2wt%, Cu: 0.7wt%, Be: 0.05wt%, Mg: 0.15wt%, with the remainder being Al and unavoidable impurities.

[0048] The preparation method for producing cast aluminum rotors using this cast aluminum alloy material includes the following steps: S1: Pre-treat the Al raw material to obtain the pre-treated Al raw material; the pre-treatment includes soaking the Al raw material in 5 times the amount of 1wt% oxalic acid solution for 20 minutes and then drying the Al raw material to obtain the pre-treated Al raw material; S2: Place the Al raw material into the melting furnace, heat it to 710℃, add the weighed Si and Cu elements, stir evenly after dissolving completely, add the refining agent, control the injection speed of the refining agent to 0.8kg / min for the first refining, keep it at the temperature for 10min, let it stand and remove the slag to obtain intermediate liquid A. S3: Heat intermediate liquid A to 720℃, add weighed Mg and Be elements, add refining agent again, and make the refining agent injection rate at 0.4kg / min for the second refining. Keep warm for 20min, let stand and remove slag to obtain intermediate liquid B. S4: Preheat the casting mold, with the upper mold temperature at 590℃ and the lower mold temperature at 390℃. Then pour the intermediate liquid B into the casting mold for centrifugation at a speed of 150r / min for 50s. After the rotor solidifies, the casting equipment stops rotating and is allowed to cool naturally for 60s. Then, it is air-cooled to room temperature to obtain the casting. S5: The casting is heat-treated and then naturally cooled to room temperature to obtain the final product; the specific heat treatment process is as follows: S100: Heat the casting to 320℃ at a heating rate of 10℃ / min, hold for 2 hours, then heat to 360℃ at a heating rate of 10℃, hold for 1 hour, then cool to 340℃ at a cooling rate of 10℃, and hold for 1 hour. S200: The heat-insulated rotor is placed in a coolant to cool to room temperature. The coolant contains 15 wt% control agent and the remainder is water. The control agent is selected from polymethyl methacrylate (molecular weight 15,000), sodium alginate (molecular weight 300,000), and hydroxyethyl cellulose (molecular weight 150,000) in a weight ratio of 7:4:2. The cooling rate of the coolant is 40℃ / s. S300: Heat to 160℃ at a heating rate of 10℃ / min and hold for 4 hours.

[0049] The refining agent includes, by weight fraction: 30 parts modified graphene, 10 parts cerium chloride, and 5 parts potassium oxalate. The preparation method of modified graphene includes the following steps: S10: After oxidizing graphene in hydrogen peroxide solution, the weight ratio of graphene to hydrogen peroxide solution is 1:4 to obtain pretreated graphene. S20: Under nitrogen protection, pretreated graphene, perfluorooctyltrichlorosilane and potassium carbonate were added to tetrahydrofuran and reacted at 50°C for 2 hours. The weight ratio of graphene, perfluorooctyltrichlorosilane and potassium carbonate was 1:0.8:0.3. After filtration and drying, modified graphene was obtained.

[0050] Example 2 This embodiment relates to a high-strength, high-wear-resistant cast aluminum alloy material, which, by weight, comprises Si: 0.5wt%, Cu: 1.0wt%, Mg: 0.5wt%, with the remainder being Al and unavoidable impurities.

[0051] The preparation method for producing cast aluminum rotors using this cast aluminum alloy material includes the following steps: S1: Pre-treat the Al raw material to obtain the pre-treated Al raw material; the pre-treatment includes soaking the Al raw material in 10 times the amount of 1wt% oxalic acid solution for 30 minutes and then drying the Al raw material to obtain the pre-treated Al raw material; S2: Place the Al raw material into the melting furnace, heat it to 730℃, add the weighed Si and Cu elements, stir evenly after complete dissolution, add the refining agent, control the injection speed of the refining agent to 1.0 kg / min for the first refining, keep it at the temperature for 15 min, let it stand and remove the slag to obtain intermediate liquid A. S3: Heat intermediate liquid A to 730℃, add the weighed Mg element, add the refining agent again, and make the refining agent injection rate at 0.6kg / min for the second refining. Keep it at the temperature for 30min, let it stand and remove the slag to obtain intermediate liquid B. S4: Preheat the casting mold, with the upper mold at 620℃ and the lower mold at 400℃. Then cool the intermediate liquid B to 720℃ and pour it into the casting mold for centrifugation at 200r / min for 60s. After the rotor solidifies, the casting equipment stops rotating and is allowed to cool naturally for 90s. Then, it is air-cooled to room temperature to obtain the casting. S5: The casting is heat-treated and then naturally cooled to room temperature to obtain the final product; the specific heat treatment process is as follows: S100: Heat the casting to 340℃ at a heating rate of 15℃ / min, hold for 4 hours, then heat to 400℃ at a heating rate of 10℃, hold for 2 hours, then cool to 350℃ at a cooling rate of 15℃, hold for 2 hours. S200: The heat-insulated rotor is placed in a coolant to cool to room temperature. The coolant contains 15 wt% control agent and the remainder is water. The control agent is selected from polymethyl methacrylate (molecular weight 25,000), sodium alginate (molecular weight 400,000), and hydroxyethyl cellulose (molecular weight 200,000) in a weight ratio of 7:4:2. The cooling rate of the coolant is 60℃ / s. S300: Heat to 160℃ at a heating rate of 10℃ / min and hold for 4 hours.

[0052] The refining agent includes, by weight fraction: 40 parts modified graphene, 20 parts cerium chloride, and 10 parts sodium oxalate. The preparation method of modified graphene includes the following steps: S10: After oxidizing graphene in hydrogen peroxide solution, the weight ratio of graphene to hydrogen peroxide solution is 1:6, resulting in pretreated graphene. S20: Under nitrogen protection, pretreated graphene, perfluorooctyltrichlorosilane and ammonium carbonate were added to tetrahydrofuran and reacted at 70°C for 1 h. The weight ratio of graphene, perfluorooctyltrichlorosilane and ammonium carbonate was 1:1:0.3. After filtration and drying, modified graphene was obtained.

[0053] Example 3 This embodiment relates to a high-strength and high-wear-resistant cast aluminum alloy material, which, by weight, includes Si: 0.3wt%, Cu: 0.9wt%, Mg: 0.2wt%, Ca: 0.15wt%, with the remainder being Al and unavoidable impurities.

[0054] The preparation method for producing cast aluminum rotors using this cast aluminum alloy material includes the following steps: S1: Pre-treat the Al raw material to obtain the pre-treated Al raw material; the pre-treatment includes soaking the Al raw material in 8 times the amount of 1wt% oxalic acid solution for 25 minutes and then drying the Al raw material to obtain the pre-treated Al raw material; S2: Place the Al raw material into the melting furnace, heat it to 720℃, add the weighed Si and Cu elements, stir evenly after complete dissolution, add the refining agent, control the injection speed of the refining agent to 0.9kg / min for the first refining, keep it at the temperature for 12min, let it stand and remove the slag to obtain intermediate liquid A. S3: Heat intermediate liquid A to 725℃, add weighed Mg and Ca elements, add refining agent again, and make the refining agent injection rate at 0.5kg / min for the second refining. Keep warm for 25min, let stand and remove slag to obtain intermediate liquid B. S4: Preheat the casting mold, with the upper mold at 600℃ and the lower mold at 395℃. Then, cool the intermediate liquid B to 720℃ and pour it into the casting mold for centrifugation at 180r / min for 55s. After the rotor solidifies, stop the casting equipment and allow it to cool naturally for 75s. Then, air cool it to room temperature to obtain the casting. S5: The casting is heat-treated and then naturally cooled to room temperature to obtain the final product; the specific heat treatment process is as follows: S100: Heat the casting to 330℃ at a heating rate of 13℃ / min, hold for 3 hours, then heat to 380℃ at a heating rate of 12℃, hold for 1.5 hours, then cool to 345℃ at a cooling rate of 12℃, and hold for 1.5 hours. S200: The heat-insulated rotor is placed in a coolant to cool to room temperature. The coolant contains 15 wt% control agent and the remainder is water. The control agent is selected from polymethyl methacrylate (molecular weight 20,000), sodium alginate (molecular weight 350,000), and hydroxyethyl cellulose (molecular weight 180,000) in a weight ratio of 7:4:2. The cooling rate of the coolant is 50℃ / s. S300: Heat to 165℃ at a heating rate of 10℃ / min and hold for 4 hours.

[0055] The refining agent includes, by weight fraction: 350 parts modified graphene, 15 parts cerium chloride, and 8 parts potassium oxalate. The preparation method of modified graphene includes the following steps: S10: After oxidizing graphene in hydrogen peroxide solution, the weight ratio of graphene to hydrogen peroxide solution is 1:5, and pretreated graphene is obtained. S20: Under nitrogen protection, pretreated graphene, perfluorooctyltrichlorosilane and sodium carbonate were added to tetrahydrofuran and reacted at 60°C for 2.5 h. The weight ratio of graphene, perfluorooctyltrichlorosilane and sodium carbonate was 1:0.9:0.3. After filtration and drying, modified graphene was obtained.

[0056] Example 4 The difference between this embodiment and Embodiment 3 is that the Mg content is 0.3 wt%.

[0057] Example 5 The difference between this embodiment and Embodiment 3 is that the cast aluminum rotor also includes 0.04wt% Be element.

[0058] Example 6 The difference between this embodiment and embodiment 3 is that the temperature is raised to 650°C in step S2.

[0059] Example 7 The difference between this embodiment and embodiment 3 is that step S1 is not performed.

[0060] Example 8 The difference between this embodiment and embodiment 3 is that the centrifugation speed in step S4 is 200 r / min.

[0061] Example 9 The difference between this embodiment and embodiment 3 is that hydroxyethyl cellulose is not added in step S200 of step S5.

[0062] Example 10 The difference between this embodiment and Embodiment 3 is that the refining agent is replaced with cryolite.

[0063] Example 11 The difference between this embodiment and Embodiment 3 is that the refining agent obtained by performing only step S10 is used.

[0064] Comparative Example 1 The difference between this comparative example and Example 3 is that Zn is used instead of Mg.

[0065] Comparative Example 2 The difference between this comparative example and Example 3 is that Ni is used instead of Ca.

[0066] Comparative Example 3 The difference between this comparative example and Example 3 is that the amount of Ca added is 0.35 wt%.

[0067] Comparative Example 4 The difference between this comparative example and Example 3 is that the amount of Mg added is 0.5 wt%. Comparative Example 5 The difference between this comparative example and Example 3 is that the amount of Si added is 0.1 wt%.

[0068] Comparative Example 6 The difference between this comparative example and Example 3 is that the amount of Si added is 0.8 wt%.

[0069] Comparative Example 7 The difference between this comparative example and Example 3 is that the amount of Cu added is 0.4 wt%.

[0070] Comparative Example 8 The difference between this comparative example and Example 3 is that the amount of Cu added is 1.2 wt%.

[0071] Test Example 1 Mechanical properties and electrical conductivity tests were conducted on end face samples of the cast aluminum rotors prepared using the alloy material of this application in the above embodiments and comparative examples. The electrical conductivity test specimens met the requirements of GB / T12966-2008 and were tested for electrical conductivity. The mechanical property test specimens met the standard of ASTM E8 and were analyzed for tensile properties. The impact resistance was tested using a cantilever beam impact strength tester in accordance with GB / T1843-2008. The test results are shown in Table 1.

[0072] Table 1

[0073] Test Example 2 Cast aluminum rotors prepared from the alloy materials of the above embodiments and comparative examples were placed in a creep tester for performance testing. The conditions for high-temperature creep resistance testing were: creep temperature 200℃, service time 1000h, and creep stress 17MPa. The friction and wear test method was carried out according to the test method disclosed in GB / T1768-2006. The load was 1kg and the rotation speed was 100 revolutions. The wear amount was tested, and the results are shown in Table 2.

[0074] Table 2

[0075] The above description is merely an embodiment of this application, and the scope of protection of this application is not limited to these specific embodiments, but is determined by the claims of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the technical concept and principles of this application should be included within the scope of protection of this application.

Claims

1. A high-strength, high-wear-resistant cast aluminum alloy material, characterized in that, By weight, it includes Si: 0.2-0.5 wt%, Cu: 0.7-1.0 wt%, Group IIA elements: 0.2-0.5 wt%, with the remainder being Al and unavoidable impurities.

2. The high-strength, high-wear-resistant cast aluminum alloy material according to claim 1, characterized in that, The weight ratio of Si, Cu and Group IIA elements is (1.2-1.4):(2.0-2.4):

1.

3. The high-strength, high-wear-resistant cast aluminum alloy material according to claim 1, characterized in that, The group IIA elements are selected from at least one of Mg, Ca, and Be.

4. The high-strength, high-wear-resistant cast aluminum alloy material according to claim 3, characterized in that, The Group IIA elements include Mg and Ca in a weight ratio of 1:(0.6-1.0).

5. The high-strength, high-wear-resistant cast aluminum alloy material according to claim 3, characterized in that, The Group IIA elements include Mg, Ca, and Be in a weight ratio of 1:(0.6-1.0):(0.1-0.2).

6. The method for preparing the high-strength, high-wear-resistant cast aluminum alloy material according to any one of claims 1-5, characterized in that, Includes the following steps: S1: Pre-treat the Al raw material to obtain the pre-treated Al raw material; S2: Place the Al raw material into the melting furnace, heat it to 710-730℃, add the weighed Si and Cu elements, stir evenly after dissolving completely, add the refining agent for the first refining, keep it at the temperature for 10-15 minutes, let it stand and remove the slag to obtain intermediate liquid A. S3: Heat intermediate liquid A to 720-730℃, add the weighed Group IIA elements, add the refining agent again for a second refining, keep warm for 20-30 minutes, let stand and remove the slag to obtain intermediate liquid B; S4: Preheat the casting mold, then cool the intermediate liquid B to 720℃ and pour it into the casting mold for centrifugation. After the alloy material solidifies, the casting equipment stops rotating and cools naturally for 60-90 seconds. Then, air cool to room temperature to obtain the casting. S5: The casting is heat-treated and then naturally cooled to room temperature to obtain the final product.

7. The preparation method according to claim 6, characterized in that, In step S4, the centrifugation speed is 150-200 r / min and the centrifugation time is 50-60 s.

8. The preparation method according to claim 6, characterized in that, In the casting mold, the temperature of the upper mold is 590-620℃, and the temperature of the lower mold is 390-400℃.

9. The preparation method according to claim 6, characterized in that, During the first refining process, the injection rate of the refining agent should be controlled at 0.8-1.0 kg / min.

10. The preparation method according to claim 6, characterized in that, During the second refining process, the rate of spraying the refining agent should be controlled at 0.4-0.6 kg / min.

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