Preparation process of light-weight aluminum alloy wheel hub

Abstract

The application provides a preparation process of a light-weight aluminum alloy hub, relates to the field of aluminum alloy materials and application technologies, and comprises the following steps: mixing and heating carbon steel and pig iron to melt, adding high-carbon manganese iron, medium-carbon chromium iron and silicon iron, refining by heating, adding aluminum powder, entering a mold, demolding by cooling, homogenizing by heating, quenching, cooling and obtaining a mother plate; mixing bismaleimide, composite powder and sepiolite fiber, stirring after heating, coating on the mother plate, applying negative pressure first, then applying positive pressure, heating, cooling and obtaining a base layer; sputtering on the base layer to obtain a chromium nitride functional layer, cooling and obtaining a high-wear-resistance alloy lining plate; the composite powder is prepared by mixing and heating chromium carbide powder and hydrogen peroxide solution, filtering, mixing with an ethanol solution and gamma-aminopropyl triethoxysilane, heating, condensing and refluxing, washing and drying, mixing with an amino-terminated polyether and N,N-dimethylformamide and heating; and the application can improve the wear-resistance stability of the alloy lining plate.

Description

Technical Field

[0001] This invention relates to the field of aluminum alloy materials and application technology, specifically to a manufacturing process for lightweight aluminum alloy wheels. Background Technology

[0002] Aluminum alloy wheels are widely used in passenger cars and new energy vehicles due to their advantages such as low density, high specific strength, good formability, and strong plasticity in appearance. With the increasing demand for lightweight and high-performance vehicles, wheels must not only meet weight reduction requirements but also maintain high mechanical strength, wear resistance, and fatigue life. The rim area, as a critical part of the wheel that directly bears the load during driving, has a decisive impact on the overall safety of the wheel due to its mechanical properties and structural reliability, thus placing higher demands on the material's density and uniformity of structure.

[0003] Currently, aluminum alloy wheels are typically manufactured using casting followed by heat treatment. During the smelting and casting processes, on the one hand, the one-piece manufacturing process commonly used for aluminum alloy wheels makes it difficult to significantly improve the mechanical properties of the rim; on the other hand, non-metallic impurities are inevitably introduced into the alloy melt. These defects easily form weak interface regions after solidification, not only reducing the material's density but also causing stress concentration during service, thereby weakening the overall mechanical properties of the rim and wheel hub.

[0004] For example, patent application CN117867337A discloses a rare-earth cast aluminum alloy for passenger car wheel hubs and a method for preparing the wheel hub, including the following steps: first, aluminum ingots, metallic silicon, aluminum-iron master alloys, and other alloys are loaded into a melting furnace and heated for melting; then, magnesium ingots, zinc ingots, and aluminum-strontium master alloys are added, and argon gas is introduced for refining to obtain a primary melt; after slag removal from the primary melt, aluminum-titanium-boron master alloys are added and heated to melt to obtain a secondary melt; the secondary melt is die-cast into a wheel hub workpiece, and then subjected to solution treatment; the solution-treated wheel hub workpiece is placed in an aging furnace for artificial aging, and then the wheel hub workpiece is removed and cooled to room temperature, and machined to obtain a passenger car wheel hub. This scheme improves the overall mechanical properties of aluminum alloy wheel hubs to a certain extent by introducing multiple alloying elements and rare earth elements into the aluminum alloy system, combined with multiple melting, refining, and heat treatment processes. However, this scheme lacks a good method for treating impurities, resulting in insufficient strengthening of the mechanical properties of the rim area.

[0005] In summary, there is a need to provide a manufacturing process for lightweight aluminum alloy wheels to solve the problems existing in the prior art. Summary of the Invention

[0006] In view of this, the present invention provides a manufacturing process for lightweight aluminum alloy wheels, thereby improving the mechanical properties of aluminum alloy wheels.

[0007] To achieve the above objectives, a manufacturing process for a lightweight aluminum alloy wheel hub includes the following steps:

[0008] S1. Add aluminum ingots, crystalline silicon and magnesium ingots into a melting furnace, heat up and melt, add aluminum-titanium-boron master alloy and aluminum-strontium master alloy, blow in argon gas to continue refining, stop the argon gas, remove the slag, add titanium-silicon composite particles, keep warm and stand to obtain alloy melt;

[0009] S2. Pour the alloy melt into the mold, seal it, heat the alloy melt electromagnetically, rotate the mold around the central axis of the mold, apply pressure, cool down to solidify, quench, artificially age, and cool to room temperature to obtain a lightweight aluminum alloy wheel hub.

[0010] The titanium-silicon composite particles are obtained by mixing aluminum-silicon alloy powder and hydrochloric acid solution, heating and stirring, filtering and washing, drying, adding to anhydrous ethanol, adjusting the pH to alkaline, heating and sonicating, adding tetrabutyl titanate solution, continuing stirring, centrifuging and drying, heating and sintering in an inert atmosphere, crushing and sieving.

[0011] This invention uses aluminum-silicon alloy powder as raw material, which is acid-dealloyed to form a silicon-based network structure. Titanium-silicon composite particles, obtained by introducing a titanium source and heat treatment under an inert atmosphere, are then added to the aluminum alloy melt. During the forming process, a centrifugal process is used to allow the titanium-silicon composite particles to migrate and accumulate in the rim area under centrifugal force, thereby improving the mechanical properties of the rim area. Specifically, titanium-silicon composite particles form a stable composite structure through heat treatment. The particles contain both high-density titanium and high-hardness silicon components, resulting in an overall apparent density higher than that of the aluminum alloy melt, while also exhibiting high mechanical stability. Furthermore, the titanium-silicon composite particles maintain an independent and stable particle morphology within the aluminum alloy melt for an extended period. During rotational forming, the density difference between the titanium-silicon composite particles and the alloy melt, combined with the centrifugal force generated by rotation, causes a significant relative displacement of the titanium-silicon composite particles relative to the aluminum alloy melt, promoting their directional migration towards the rim area. During alloy solidification and subsequent heat treatment, the titanium-silicon composite particles enriched in the rim area remain in that region and participate in the formation of the overall material structure. Under external loads, they provide support and load sharing to the aluminum alloy matrix, thereby contributing to improved mechanical properties in the rim area.

[0012] Optionally, in step S1, before adding the aluminum ingot, crystalline silicon, and magnesium ingot into the melting furnace, porous boron nitride particles are uniformly spread at the bottom of the melting furnace. The apparent density of the porous boron nitride particles is 1.2~1.8 g / cm³. 3 The argon gas is blown in from the bottom of the melting furnace at a flow rate of 1.5~2.5L / min.

[0013] This invention first lays porous boron nitride particles at the bottom of a melting furnace, then adds raw materials such as aluminum ingots into the furnace. After melting the raw materials by heating, the low apparent density of the porous boron nitride particles, combined with bottom-blowing argon gas, improves impurity removal and enhances the mechanical properties of the wheel hub. As the raw materials gradually melt to form an alloy melt, the porous boron nitride particles, due to their lower apparent density than the alloy melt, begin to float from the bottom of the furnace. During this floating process, the porous structure of the boron nitride particles effectively adsorbs non-metallic impurities in the alloy melt, carrying them to the surface of the alloy melt along with the particles. Slag removal further enhances the impurity removal effect. Simultaneously, this invention introduces inert argon gas at the bottom of the melting furnace, generating an upward bubble flow. This allows the porous boron nitride particles to continuously rise within the high-viscosity alloy melt, overcoming the resistance of the high-viscosity alloy melt to the movement of the porous boron nitride particles and preventing their upward movement from stagnating. This allows the porous boron nitride particles to move to the surface of the alloy melt for slag removal. The alloy melt treated in this way can effectively reduce the damage to the microstructure caused by impurities during subsequent processing, thus improving the hardness of the wheel hub.

[0014] Optionally, the porous boron nitride particles are obtained by dissolving borax in deionized water, adding melamine, stirring evenly, heating to 75-80℃ and maintaining a constant temperature until the water evaporates, pressing at a pressure of 5-6 MPa for 10-15 minutes, placing in a tube furnace, introducing nitrogen gas, heating at a rate of 8-10℃ / min to 1000-1050℃ for 100-110 minutes, cooling to 600-620℃, introducing air for 3-4 hours, cooling to room temperature, crushing the obtained solid, washing it 2-3 times with deionized water, passing it through a 5-10 mesh sieve, and then vacuum drying.

[0015] In this invention, porous boron nitride particles are prepared by reacting borax and melamine at high temperature under a nitrogen atmosphere, followed by controlled oxidation treatment. These porous boron nitride particles, characterized by low apparent density, high porosity, and high-temperature resistance, do not melt or decompose during the smelting process. They effectively adsorb and carry oxides and non-metallic inclusions from the alloy melt to the surface, thereby improving slag removal efficiency and enhancing the cleanliness of the aluminum alloy melt.

[0016] Optionally, the titanium-silicon composite particles are prepared by adding aluminum-silicon alloy powder to a hydrochloric acid solution, heating to 50-55°C and stirring for 10-12 hours, filtering, rinsing with deionized water 2-3 times, and drying to form porous particles; adding the porous particles to anhydrous ethanol, adjusting the pH to 8.5-10.5 with ammonia, heating to 45-50°C and ultrasonically stirring for 20-40 minutes, adding tetrabutyl titanate solution, continuing stirring for 24-26 hours, centrifuging and drying, sintering at 950-1100°C in an argon atmosphere for 60-120 minutes, crushing, and passing through a 100-140 mesh sieve; the apparent density of the titanium-silicon composite particles is 2.7-3.3 g / cm³. 3 .

[0017] In this invention, titanium-silicon composite particles with a stable composite structure are obtained by using aluminum-silicon alloy powder as a precursor, forming a porous structure through deacidification treatment, introducing a titanium source on its surface, and then sintering it at high temperature in an inert atmosphere. These titanium-silicon composite particles combine the high strength of the titanium component with the high hardness of the silicon skeleton, and have an apparent density higher than that of the alloy melt, enabling them to migrate directionally to the rim area under centrifugal force. This facilitates the formation of a reinforced distribution in the rim area and improves the mechanical properties of the rim.

[0018] Optionally, in step S1, aluminum ingots, crystalline silicon, and magnesium ingots are added to a melting furnace and heated to 720-760°C for 40-70 minutes. Then, aluminum-titanium-boron master alloy and aluminum-strontium master alloy are added. Argon gas with a flow rate of 1.5-2.5 L / min is introduced into the bottom of the furnace for 10-25 minutes. After stopping the argon gas supply and removing the slag, titanium-silicon composite particles are added and the mixture is kept at a constant temperature for 15-30 minutes to obtain the alloy melt.

[0019] This invention first adds aluminum-titanium-boron master alloy and aluminum-strontium master alloy during the smelting stage, and then uses bottom-blown argon refining and slag removal to fully remove impurities from the alloy melt and improve its cleanliness. After refining and slag removal, titanium-silicon composite particles are added, and then allowed to stand at a constant temperature to fully wet and evenly disperse them with the alloy melt. This effectively prevents the titanium-silicon composite particles from agglomerating with impurities and becoming defect sources, thereby improving the utilization efficiency of the titanium-silicon composite particles in the alloy melt and laying the foundation for the effective migration of titanium-silicon composite particles during the subsequent centrifugal forming process.

[0020] Optionally, in step S2, the alloy melt is poured into a mold, heated to 700~720℃ by electromagnetic heating, the mold is rotated around the central axis of the mold, and after the rotation stops, a pressure of 80~120MPa is applied and held for 2~4 minutes, the temperature is lowered to 540~560℃ for solution treatment for 1~3 hours, and after water quenching, a blank is obtained. After artificial aging treatment, it is cooled to room temperature to obtain a lightweight aluminum alloy wheel hub.

[0021] In this invention, electromagnetic heating of the alloy melt after casting, combined with rotational molding and pressurized solidification, helps to improve the filling stability and forming density of the alloy melt. Combined with subsequent solution treatment, water quenching and artificial aging treatment, the microstructure of the alloy can be further optimized, the probability of defect formation can be reduced, thereby improving the overall mechanical properties of the lightweight aluminum alloy wheel hub.

[0022] In this invention, during the alloy melt and aluminum alloy wheel hub forming process, the titanium-silicon composite particles do not undergo overall melting and can maintain an independent and stable particle morphology in the aluminum alloy melt for a long time. Thus, during the rotational forming process, under the combined action of the density difference between the titanium-silicon composite particles and the alloy melt and the centrifugal force generated by rotation, the titanium-silicon composite particles generate a significant relative displacement relative to the aluminum alloy melt, causing the titanium-silicon composite particles to migrate directionally towards the rim area.

[0023] Optionally, the rotation speed of the mold is 1000~1500 rpm, and the rotation time is 100~120s; the water quenching temperature is 20~30℃, and the water quenching time is 50~70s; the artificial aging temperature is 175~190℃, and the time is 5~8h.

[0024] Optionally, the lightweight aluminum alloy wheel hub comprises the following raw materials in parts by weight: 915-935 parts aluminum ingot, 45-60 parts crystalline silicon, 5-7 parts magnesium ingot, 1-2 parts aluminum-titanium-boron master alloy, 0.15-0.3 parts aluminum-strontium master alloy, and 7-11 parts titanium-silicon composite particles.

[0025] Optionally, the titanium-silicon composite particles comprise the following raw materials in parts by weight: 15-17 parts aluminum-silicon alloy powder, 500-600 parts 10wt% hydrochloric acid solution, 300-500 parts anhydrous ethanol, and 60-100 parts 8wt% tetrabutyl titanate solution.

[0026] Optionally, the porous boron nitride particles comprise the following raw materials in parts by weight: 2-2.2 parts borax, 100-120 parts deionized water, and 10-12 parts melamine.

[0027] The above-described technical solution of the present invention has at least the following beneficial effects:

[0028] This invention introduces titanium-silicon composite particles into the alloy melt and, combined with rotational centrifugation, causes these particles to migrate and accumulate in the rim region, thereby improving the mechanical properties of the rim region. The overall apparent density of the titanium-silicon composite particles is higher than that of the aluminum alloy melt, and these particles maintain an independent and stable particle morphology within the aluminum alloy melt for an extended period. During rotational forming, the density difference between the titanium-silicon composite particles and the alloy melt, along with the centrifugal force generated by rotation, causes a significant relative displacement of the titanium-silicon composite particles relative to the aluminum alloy melt, promoting their directional migration towards the rim region. During alloy solidification and subsequent heat treatment, the titanium-silicon composite particles accumulated in the rim region remain in that area and participate in the formation of the overall material structure, thus contributing to improved mechanical properties of the rim region. Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. The described embodiments are some embodiments of the present invention, and all other embodiments obtained by those skilled in the art based on the described embodiments of the present invention are within the scope of protection of the present invention.

[0030] Example 1

[0031] By weight, 15 parts of aluminum-silicon alloy powder (silicon content 20 wt%, particle size 6 μm) were added to 500 parts of 10 wt% hydrochloric acid solution, heated to 50℃ and stirred for 10 h, filtered, rinsed twice with deionized water and dried to form porous particles; the porous particles were added to 300 parts of anhydrous ethanol, ammonia was added to adjust the pH to 8.5, heated to 45℃ and ultrasonically stirred for 20 min, 60 parts of 8 wt% tetrabutyl titanate solution were added, and the reaction was continued with stirring for 24 h, centrifuged and dried, heated to 950℃ in an argon atmosphere and sintered for 60 min, crushed, passed through a 100-mesh sieve, and the particles with an apparent density of 2.7 g / cm³ were sorted out. 3 Titanium-silicon composite particles.

[0032] By weight, 2 parts borax were dissolved in 100 parts deionized water, and 10 parts melamine were added. The mixture was stirred until homogeneous, heated to 75°C and kept at a constant temperature until the moisture evaporated. The mixture was then pressed at 5 MPa for 10 minutes, placed in a tube furnace, and nitrogen gas was introduced. The temperature was increased to 1000°C at a rate of 8°C / min and treated for 100 minutes. The temperature was then lowered to 600°C, and air was introduced for 3 hours. After cooling to room temperature, the resulting solid was crushed, washed twice with deionized water, vacuum dried, and passed through a 5-mesh sieve. The solid with an apparent density of 1.2 g / cm³ was then separated. 3 Porous boron nitride particles.

[0033] By weight, 8 parts of porous boron nitride particles were evenly spread at the bottom of the melting furnace, and 915 parts of aluminum ingot, 45 parts of crystalline silicon and 5 parts of magnesium ingot were added. The temperature was raised to 720℃ and melted for 40 minutes. 1 part of aluminum-titanium-boron master alloy and 0.15 parts of aluminum-strontium master alloy were added. Argon gas with a flow rate of 1.5 L / min was continuously introduced into the bottom of the melting furnace through a spray gun for 10 minutes. After stopping the argon gas supply and removing the slag, 7 parts of titanium-silicon composite particles were added and kept at the temperature for 15 minutes to obtain the alloy melt.

[0034] The alloy melt is poured into a mold, the mold is sealed, and the temperature of the alloy melt is heated to 700℃ by electromagnetic heating. The mold is rotated around its central axis at a speed of 1000 rpm for 100 seconds. The rotation is stopped, and a pressure of 80 MPa is applied and held for 2 minutes. The temperature is then lowered to 540℃ for solution treatment for 1 hour. The blank is then transferred to water at 20℃ for water quenching for 50 seconds to obtain a blank. The blank is then heated to 175℃ for artificial aging treatment for 5 hours. After cooling to room temperature, a lightweight aluminum alloy wheel hub is obtained.

[0035] Example 2

[0036] By weight, 16 parts of aluminum-silicon alloy powder (silicon content 20 wt%, particle size 7 μm) were added to 550 parts of 10 wt% hydrochloric acid solution, heated to 52℃ and stirred for 11 h, filtered, rinsed three times with deionized water and dried to form porous particles; the porous particles were added to 400 parts of anhydrous ethanol, ammonia was added to adjust the pH to 9, heated to 47℃ and ultrasonically stirred for 30 min, 80 parts of 8 wt% tetrabutyl titanate solution were added, and the reaction was continued with stirring for 25 h, centrifuged and dried, heated to 1000℃ in an argon atmosphere and sintered for 110 min, crushed, passed through a 120 mesh sieve, and the particles with an apparent density of 3 g / cm³ were sorted out. 3 Titanium-silicon composite particles.

[0037] By weight, 2.1 parts borax were dissolved in 110 parts deionized water, and 11 parts melamine were added. The mixture was stirred until homogeneous, heated to 78°C and kept at a constant temperature until the moisture evaporated. The mixture was then pressed at 5.5 MPa for 12 minutes, placed in a tube furnace, and nitrogen gas was introduced. The temperature was increased to 1020°C at a rate of 10°C / min and treated for 105 minutes. The temperature was then lowered to 610°C, and air was introduced for 3.5 hours. After cooling to room temperature, the resulting solid was crushed, washed three times with deionized water, vacuum dried, and passed through a 6-mesh sieve. Samples with an apparent density of 1.5 g / cm³ were then separated. 3 Porous boron nitride particles.

[0038] By weight, 9 parts of porous boron nitride particles were evenly spread at the bottom of the melting furnace, and 920 parts of aluminum ingot, 55 parts of crystalline silicon and 6 parts of magnesium ingot were added. The temperature was raised to 740℃ and melted for 55 minutes. 1.5 parts of aluminum-titanium-boron master alloy and 0.2 parts of aluminum-strontium master alloy were added. Argon gas with a flow rate of 2L / min was introduced into the bottom of the melting furnace through a spray gun for 20 minutes. After stopping the argon gas supply and removing the slag, 9 parts of titanium-silicon composite particles were added and kept at the temperature for 25 minutes to obtain the alloy melt.

[0039] The alloy melt is poured into a mold, the mold is sealed, and the temperature of the alloy melt is heated to 710℃ by electromagnetic heating. The mold is rotated around its central axis at a speed of 1200 rpm for 110 seconds. The rotation is stopped, and a pressure of 100 MPa is applied and held for 3 minutes. The temperature is then lowered to 550℃ for solution treatment for 2 hours. The blank is then transferred to water at 25℃ for water quenching for 60 seconds to obtain a blank. The blank is then heated to 180℃ for artificial aging treatment for 6 hours. After cooling to room temperature, a lightweight aluminum alloy wheel hub is obtained.

[0040] Example 3

[0041] By weight, 17 parts of aluminum-silicon alloy powder (silicon content 20 wt%, particle size 8 μm) were added to 600 parts of 10 wt% hydrochloric acid solution, heated to 55℃ and stirred for 12 h, filtered, rinsed three times with deionized water and dried to form porous particles; the porous particles were added to 500 parts of anhydrous ethanol, ammonia was added to adjust the pH to 10.5, heated to 50℃ and ultrasonically stirred for 40 min, 100 parts of 8 wt% tetrabutyl titanate solution were added, and the reaction was continued with stirring for 26 h, centrifuged and dried, heated to 1100℃ in an argon atmosphere and sintered for 120 min, crushed, passed through a 140 mesh sieve, and the particles with an apparent density of 3.3 g / cm³ were sorted. 3 Titanium-silicon composite particles.

[0042] By weight, 2.2 parts of borax were dissolved in 120 parts of deionized water, and 12 parts of melamine were added. The mixture was stirred until homogeneous, heated to 80°C and kept at a constant temperature until the moisture evaporated. The mixture was then pressed at 6 MPa for 15 minutes, placed in a tube furnace, and nitrogen gas was introduced. The temperature was increased to 1050°C at a rate of 10°C / min for 110 minutes. The temperature was then lowered to 620°C, and air was introduced for 4 hours. After cooling to room temperature, the resulting solid was crushed, washed three times with deionized water, vacuum dried, and passed through a 10-mesh sieve. The solid with an apparent density of 1.8 g / cm³ was then separated. 3 Porous boron nitride particles.

[0043] By weight, 10 parts of porous boron nitride particles were evenly spread at the bottom of the melting furnace, and 935 parts of aluminum ingot, 60 parts of crystalline silicon and 7 parts of magnesium ingot were added. The temperature was raised to 760℃ and melted for 70 min. 2 parts of aluminum-titanium-boron master alloy and 0.3 parts of aluminum-strontium master alloy were added. Argon gas with a flow rate of 2.5 L / min was introduced into the bottom of the melting furnace through a spray gun for 25 min. After stopping the argon gas supply and removing the slag, 11 parts of titanium-silicon composite particles were added and kept at the temperature for 30 min to obtain the alloy melt.

[0044] The alloy melt is poured into a mold, the mold is sealed, and the temperature of the alloy melt is heated to 720℃ by electromagnetic heating. The mold is rotated around its central axis at a speed of 1500 rpm for 120 seconds. The rotation is stopped, and a pressure of 120 MPa is applied and held for 4 minutes. The temperature is then lowered to 560℃ for solution treatment for 3 hours. The blank is then transferred to water at 30℃ for water quenching for 70 seconds to obtain a blank. The blank is then heated to 190℃ for artificial aging treatment for 8 hours. After cooling to room temperature, a lightweight aluminum alloy wheel hub is obtained.

[0045] Example 4

[0046] By weight, 15 parts of aluminum-silicon alloy powder (silicon content 20 wt%, particle size 6 μm) were added to 500 parts of 10 wt% hydrochloric acid solution, heated to 50℃ and stirred for 10 h, filtered, rinsed twice with deionized water and dried to form porous particles; the porous particles were added to 300 parts of anhydrous ethanol, ammonia was added to adjust the pH to 8.5, heated to 45℃ and ultrasonically stirred for 20 min, 60 parts of 8 wt% tetrabutyl titanate solution were added, and the reaction was continued with stirring for 24 h, centrifuged and dried, heated to 950℃ in an argon atmosphere and sintered for 60 min, crushed, passed through a 100-mesh sieve, and the particles with an apparent density of 2.7 g / cm³ were sorted out. 3 Titanium-silicon composite particles.

[0047] By weight, 915 parts aluminum ingot, 45 parts crystalline silicon and 5 parts magnesium ingot were added to a melting furnace and heated to 720℃ for 40 min. Then, 1 part aluminum-titanium-boron master alloy and 0.15 parts aluminum-strontium master alloy were added. Argon gas was introduced into the melting furnace at a flow rate of 1.5 L / min for 10 min. After stopping the argon gas supply and removing the slag, 7 parts titanium-silicon composite particles were added and kept at the temperature for 15 min to obtain the alloy melt.

[0048] The alloy melt is poured into a mold, the mold is sealed, and the temperature of the alloy melt is heated to 700℃ by electromagnetic heating. The mold is rotated around its central axis at a speed of 1000 rpm for 100 seconds. The rotation is stopped, and a pressure of 80 MPa is applied and held for 2 minutes. The temperature is then lowered to 540℃ for solution treatment for 1 hour. The blank is then transferred to water at 20℃ for water quenching for 50 seconds to obtain a blank. The blank is then heated to 175℃ for artificial aging treatment for 5 hours. After cooling to room temperature, a lightweight aluminum alloy wheel hub is obtained.

[0049] Example 5

[0050] By weight, 16 parts of aluminum-silicon alloy powder (silicon content 20 wt%, particle size 7 μm) were added to 550 parts of 10 wt% hydrochloric acid solution, heated to 52℃ and stirred for 11 h, filtered, rinsed three times with deionized water and dried to form porous particles; the porous particles were added to 400 parts of anhydrous ethanol, ammonia was added to adjust the pH to 9, heated to 47℃ and ultrasonically stirred for 30 min, 80 parts of 8 wt% tetrabutyl titanate solution were added, and the reaction was continued with stirring for 25 h, centrifuged and dried, heated to 1000℃ in an argon atmosphere and sintered for 110 min, crushed, passed through a 120 mesh sieve, and the particles with an apparent density of 3 g / cm³ were sorted out. 3 Titanium-silicon composite particles.

[0051] By weight, 920 parts aluminum ingot, 55 parts crystalline silicon and 6 parts magnesium ingot were added to a melting furnace and heated to 740℃ for 55 minutes. 1.5 parts aluminum-titanium-boron master alloy and 0.2 parts aluminum-strontium master alloy were added. Argon gas with a flow rate of 2L / min was introduced into the bottom of the melting furnace through a spray gun for 20 minutes. After stopping the argon gas supply and removing the slag, 9 parts titanium-silicon composite particles were added and kept at the temperature for 25 minutes to obtain the alloy melt.

[0052] The alloy melt is poured into a mold, the mold is sealed, and the temperature of the alloy melt is heated to 710℃ by electromagnetic heating. The mold is rotated around its central axis at a speed of 1200 rpm for 110 seconds. The rotation is stopped, and a pressure of 100 MPa is applied and held for 3 minutes. The temperature is then lowered to 550℃ for solution treatment for 2 hours. The blank is then transferred to water at 25℃ for water quenching for 60 seconds to obtain a blank. The blank is then heated to 180℃ for artificial aging treatment for 6 hours. After cooling to room temperature, a lightweight aluminum alloy wheel hub is obtained.

[0053] Example 6

[0054] By weight, 17 parts of aluminum-silicon alloy powder (silicon content 20 wt%, particle size 8 μm) were added to 600 parts of 10 wt% hydrochloric acid solution, heated to 55℃ and stirred for 12 h, filtered, rinsed three times with deionized water and dried to form porous particles; the porous particles were added to 500 parts of anhydrous ethanol, ammonia was added to adjust the pH to 10.5, heated to 50℃ and ultrasonically stirred for 40 min, 100 parts of 8 wt% tetrabutyl titanate solution were added, and the reaction was continued with stirring for 26 h, centrifuged and dried, heated to 1100℃ in an argon atmosphere and sintered for 120 min, crushed, passed through a 140 mesh sieve, and the particles with an apparent density of 3.3 g / cm³ were sorted. 3 Titanium-silicon composite particles.

[0055] By weight, 935 parts aluminum ingot, 60 parts crystalline silicon and 7 parts magnesium ingot were added to a melting furnace and heated to 760℃ for 70 min. Then, 2 parts aluminum-titanium-boron master alloy and 0.3 parts aluminum-strontium master alloy were added. Argon gas with a flow rate of 2.5 L / min was introduced into the bottom of the melting furnace through a spray gun for 25 min. After stopping the argon gas supply and removing the slag, 11 parts titanium-silicon composite particles were added and kept at the temperature for 30 min to obtain the alloy melt.

[0056] The alloy melt is poured into a mold, the mold is sealed, and the temperature of the alloy melt is heated to 720℃ by electromagnetic heating. The mold is rotated around its central axis at a speed of 1500 rpm for 120 seconds. The rotation is stopped, and a pressure of 120 MPa is applied and held for 4 minutes. The temperature is then lowered to 560℃ for solution treatment for 3 hours. The blank is then transferred to water at 30℃ for water quenching for 70 seconds to obtain a blank. The blank is then heated to 190℃ for artificial aging treatment for 8 hours. After cooling to room temperature, a lightweight aluminum alloy wheel hub is obtained.

[0057] The present invention also includes comparative examples and related experiments.

[0058] Comparative Example 1

[0059] The only difference from Example 1 is that no titanium-silicon composite particles were added; all other components and preparation steps were exactly the same, resulting in a lightweight aluminum alloy wheel hub.

[0060] Comparative Example 2

[0061] The only difference from Example 1 is that the mold was not rotated, but the other components and preparation steps were completely the same, resulting in a lightweight aluminum alloy wheel hub.

[0062] Comparative Example 3

[0063] The only difference from Example 1 is that the alloy melt was not heated electromagnetically, while the other components and preparation steps are completely the same, resulting in a lightweight aluminum alloy wheel hub.

[0064] Performance testing:

[0065] The mechanical properties of the lightweight aluminum alloy wheel rims prepared in Examples 1-6 and Comparative Examples 1-3 were tested according to the national standard GB / T 26036-2020 "Aluminum Alloy Forgings for Automobile Wheels" for tensile strength Rm1, Brinell hardness HBW1 and elongation after fracture A1. The test results are shown in Table 1.

[0066] Table 1. Test results of mechanical properties of wheel rims

[0067]

[0068] The tensile strength Rm1 of the lightweight aluminum alloy wheel hubs in Examples 1-6 is distributed in the range of 335-366 MPa, the Brinell hardness HBW1 is distributed in the range of 103-115, and the elongation after fracture A1 is distributed in the range of 9.4-10.2. This shows that the scheme in this invention has good repeatability, and the lightweight aluminum alloy wheel hubs prepared meet the requirements of the national standard GB / T 26036-2020 "Aluminum Alloy Forgings for Automobile Wheel Hubs".

[0069] Compared to Examples 1-3, the tensile strength Rm1 and Brinell hardness HBW1 of the lightweight aluminum alloy wheel hubs in Examples 4-6 are reduced, indicating that uniformly spreading porous boron nitride particles at the bottom of the smelting furnace before adding raw materials such as aluminum ingots, crystalline silicon and magnesium ingots into the smelting furnace, and blowing argon gas from the bottom of the smelting furnace helps to improve the mechanical properties of the lightweight aluminum alloy wheel hub rims.

[0070] Based on the test results in Table 1, compared to Example 1, Comparative Example 1 did not add titanium-silicon composite particles, and Comparative Example 2 did not rotate the mold. The tensile strength Rm1 and Brinell hardness HBW1 of the rims in Comparative Example 1 and Comparative Example 2 both decreased. This indicates that adding titanium-silicon composite particles and combining them with the mold rotation process helps to improve the mechanical properties of the rims of lightweight aluminum alloy wheels. Compared to Example 1, Comparative Example 3 did not use electromagnetic heating of the alloy melt, and the tensile strength Rm1 and Brinell hardness HBW1 of the rims also decreased. This indicates that using electromagnetic heating of the alloy melt followed by mold rotation helps to improve the mechanical properties of the rims of lightweight aluminum alloy wheels.

[0071] The mechanical properties of the spokes of the lightweight aluminum alloy wheel hubs prepared in Examples 1-6 and Comparative Examples 1-3 were tested according to the national standard GB / T 26036-2020 "Aluminum Alloy Forgings for Automobile Wheel Hubs", with tensile strength Rm2, Brinell hardness HBW2 and elongation after fracture A2. The test results are shown in Table 2.

[0072] Table 2. Test results of mechanical properties of wheel spokes

[0073]

[0074] As can be seen from Tables 1 and 2, the tensile strength of the rims in Examples 1 to 6 is higher than that of the spokes, and the Brinell hardness of the rims in Examples 1 to 6 is higher than that of the spokes. This indicates that the solution of the present invention helps to improve the mechanical properties of the rims of lightweight aluminum alloy wheels.

[0075] The above are preferred embodiments of the present invention. Those skilled in the art can make several improvements and modifications without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A manufacturing process for a lightweight aluminum alloy wheel hub, the wheel hub comprising spokes and a rim, characterized in that, The preparation steps include the following: S1. Add aluminum ingots, crystalline silicon and magnesium ingots into a melting furnace, heat up and melt, add aluminum-titanium-boron master alloy and aluminum-strontium master alloy, blow in argon gas to continue refining, stop the argon gas, remove the slag, add titanium-silicon composite particles, keep warm and stand to obtain alloy melt; S2. Pour the alloy melt into the mold, seal it, heat the alloy melt electromagnetically, rotate the mold around the central axis of the mold, apply pressure, cool down to solidify, quench, artificially age, and cool to room temperature to obtain a lightweight aluminum alloy wheel hub. The titanium-silicon composite particles are obtained by adding aluminum-silicon alloy powder to a hydrochloric acid solution, heating to 50-55℃ and stirring for 10-12 hours, filtering, rinsing with deionized water 2-3 times, and drying to form porous particles. The porous particles are then added to anhydrous ethanol, ammonia is added to adjust the pH to 8.5-10.5, heated to 45-50℃ and ultrasonically stirred for 20-40 minutes, tetrabutyl titanate solution is added, stirring is continued for 24-26 hours, centrifuged and dried, sintered at 950-1100℃ under an argon atmosphere for 60-120 minutes, crushed, and passed through a 100-140 mesh sieve. The apparent density of the titanium-silicon composite particles is 2.7-3.3 g / cm³. 3 ; The titanium-silicon composite particles comprise the following raw materials in parts by weight: 15-17 parts aluminum-silicon alloy powder, 500-600 parts 10wt% hydrochloric acid solution, 300-500 parts anhydrous ethanol, and 60-100 parts 8wt% tetrabutyl titanate solution. The lightweight aluminum alloy wheel hub comprises the following raw materials in parts by weight: 915-935 parts aluminum ingot, 45-60 parts crystalline silicon, 5-7 parts magnesium ingot, 1-2 parts aluminum-titanium-boron master alloy, 0.15-0.3 parts aluminum-strontium master alloy, and 7-11 parts titanium-silicon composite particles.

2. The manufacturing process of a lightweight aluminum alloy wheel hub according to claim 1, characterized in that, In step S1, before adding aluminum ingots, crystalline silicon, and magnesium ingots into the melting furnace, porous boron nitride particles are uniformly spread at the bottom of the furnace. The apparent density of the porous boron nitride particles is 1.2~1.8 g / cm³. 3 The argon gas is blown in from the bottom of the melting furnace at a flow rate of 1.5~2.5L / min.

3. The manufacturing process of a lightweight aluminum alloy wheel hub according to claim 2, characterized in that, The porous boron nitride particles are obtained by dissolving borax in deionized water, adding melamine, stirring evenly, heating to 75-80℃ and maintaining a constant temperature until the water evaporates, pressing at a pressure of 5-6 MPa for 10-15 minutes, placing in a tube furnace, introducing nitrogen gas, heating at a rate of 8-10℃ / min to 1000-1050℃ for 100-110 minutes, cooling to 600-620℃, introducing air for 3-4 hours, cooling to room temperature, crushing the resulting solid, washing it 2-3 times with deionized water, passing it through a 5-10 mesh sieve, and then vacuum drying.

4. The manufacturing process of a lightweight aluminum alloy wheel hub according to claim 1, characterized in that, In step S1, aluminum ingots, crystalline silicon, and magnesium ingots are added to a melting furnace and heated to 720-760°C for 40-70 minutes. Aluminum-titanium-boron master alloy and aluminum-strontium master alloy are added. Argon gas with a flow rate of 1.5-2.5 L / min is introduced into the bottom of the furnace for 10-25 minutes. After stopping the argon gas supply and removing slag, titanium-silicon composite particles are added and the mixture is kept at a constant temperature for 15-30 minutes to obtain the alloy melt.

5. The manufacturing process of a lightweight aluminum alloy wheel hub according to claim 1, characterized in that, In step S2, the alloy melt is poured into a mold and heated to 700-720°C by electromagnetic heating. The mold is rotated around its central axis. After the rotation stops, a pressure of 80-120 MPa is applied and held for 2-4 minutes. The temperature is then lowered to 540-560°C for solution treatment for 1-3 hours. After water quenching, a blank is obtained. After artificial aging treatment, it is cooled to room temperature to obtain a lightweight aluminum alloy wheel hub.

6. The manufacturing process of a lightweight aluminum alloy wheel hub according to claim 5, characterized in that, The rotation speed of the mold is 1000~1500 rpm, and the rotation time is 100~120s; the water quenching temperature is 20~30℃, and the water quenching time is 50~70s; the artificial aging temperature is 175~190℃, and the time is 5~8h.

7. The manufacturing process of a lightweight aluminum alloy wheel hub according to claim 2, characterized in that, The porous boron nitride particles comprise the following raw materials in parts by weight: 2-2.2 parts borax, 100-120 parts deionized water, and 10-12 parts melamine.

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