An aluminum alloy material suitable for automotive control arms and its preparation method

Abstract

This invention discloses an aluminum alloy material suitable for automotive control arms, with the following composition and mass percentages: Si: 0.7%-0.9%, Fe: 0.1%-0.2%, Mn: 0.45%-0.65%, V: 0.05%-0.15%, Mg: 1.15%-1.35%, Zr: 0.1%-0.2%, RE: 0.1%-0.2%, with the balance being Al and other unavoidable impurity elements. Specifically, Mg+Si≤2.2%; 0.15%≤Zr+RE≤0.35%; 0.45%≤Mn+V≤0.75%. The preparation method of the above aluminum alloy material includes the steps of smelting, casting, extrusion, and deformation heat treatment. The aluminum alloy material of this invention optimizes the alloy element composition. By adding elements such as Si, Mg, Mn, V, Zr, and RE and strictly controlling their contents, the material achieves high strength, high elongation, high fracture toughness, and high fatigue resistance. The aluminum alloy automotive control arm forgings prepared using this method have excellent wear resistance and impact resistance, good safety and long service life, and its short-process and low-cost preparation method is an excellent alternative to automotive control arms currently on the market.

Description

Technical Field

[0001] This invention relates to the field of aluminum alloy materials, and more specifically to an aluminum alloy material suitable for automotive control arms and its preparation method. Background Technology

[0002] The control arm, located in the suspension system, serves as a guide and support for the suspension and is a crucial component of the chassis suspension system. It connects the frame and wheels, acting as a shock absorber to ensure vehicle stability during driving. Damage to the control arm can reduce vehicle stability, make steering difficult to control, and even cause malfunctions when driving on uneven roads, increasing the risk of accidents.

[0003] The control arm plays a crucial role in automobiles. Currently, control arms are mainly made of two types of materials: cast iron or steel, and aluminum alloy. Cast iron or steel control arms are more widely used, with most car models employing them primarily due to their relatively low cost, allowing for better control of overall vehicle costs. The biggest advantage of aluminum alloy is its light weight. While lightweighting is a design consideration for automobiles, it also increases manufacturing costs. Furthermore, compared to steel control arms, existing aluminum alloy control arms exhibit inferior strength, toughness, and fatigue resistance.

[0004] Based on existing aluminum alloy automotive control arms, improving their fracture toughness and fatigue resistance while maintaining lightweight design and increasing service life is an important direction of this invention. Summary of the Invention

[0005] The purpose of this invention is to provide an aluminum alloy material suitable for automotive control arms and a method for preparing the same.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] An aluminum alloy material suitable for automotive control arms, characterized in that the components and their mass percentages are: Si: 0.7%-0.9%, Fe: 0.1%-0.2%, Mn: 0.45%-0.65%, V: 0.05%-0.15%, Mg:

[0008] 1.15%-1.35%, Zr: 0.1%-0.2%, RE: 0.1%-0.2%, balance being Al and other unavoidable impurity elements.

[0009] According to the above-mentioned aluminum alloy material, the components and their mass percentages are as follows: Si: 0.85%, Fe: 0.15%, Mn: 0.58%, V: 0.10%, Mg: 1.32%, Zr: 0.15%, RE: 0.12%, with the balance being Al and other unavoidable impurity elements.

[0010] According to the above-mentioned aluminum alloy material, the aluminum alloy material is characterized in that: Mg+Si≤2.2%.

[0011] According to the above-mentioned aluminum alloy material, the aluminum alloy material is characterized in that: 0.15% ≤ Zr + RE ≤ 0.35%.

[0012] According to the above-mentioned aluminum alloy material, the aluminum alloy material is characterized in that: 0.45% ≤ Mn + V ≤ 0.75%.

[0013] A method for preparing the above-mentioned aluminum alloy material, characterized in that the method includes the following steps:

[0014] (1) Smelting: Add each component to the smelting furnace according to the mass percentage, melt, refine, remove slag, and let stand to obtain aluminum alloy melt;

[0015] (2) Casting: Casting molten aluminum alloy into ingots;

[0016] (3) Extrusion: Extruding aluminum alloy ingots to obtain rod-shaped raw materials;

[0017] (4) Deformation heat treatment: The rod-shaped raw material obtained in step (3) is heated and forged into shape to obtain aluminum alloy car sway bar.

[0018] The arm is forged and then quenched and aged.

[0019] According to the above method, the characteristic is that the smelting process in step (1) is as follows: according to the mass percentage, pure aluminum, pure magnesium, and aluminum-silicon alloy are first added to the smelting furnace, heated to 720-730℃ and stirred to completely melt the alloy, then aluminum-iron alloy, aluminum-manganese alloy, aluminum-vanadium alloy, aluminum-zirconium alloy and aluminum rare earth intermediate alloy are added, and the temperature is further raised to 750-760℃. After all the alloy elements are melted, the mixture is stirred and sampled to adjust the composition; the temperature of the aluminum alloy melt is adjusted to 730-740℃, a refining agent is sprayed in for refining treatment, then the temperature is raised to 760-780℃, argon gas is introduced for degassing refining, and slag is removed after refining; the refined aluminum alloy melt is allowed to stand until the temperature of the aluminum alloy melt drops to 730-740℃.

[0020] According to the above method, the casting process in step (2) is as follows: the aluminum alloy melt treated in step (1) is cast into shape by a hot-top casting machine, wherein the casting speed is 85-95 mm / min, the cooling water pressure is 0.06-0.08 MPa, and the temperature of the aluminum alloy melt is maintained at 730-740℃.

[0021] According to the above method, the extrusion process in step (3) is characterized by: preheating the aluminum alloy ingot, die, and extruder. The preheating temperature of the aluminum alloy ingot is 480℃-500℃, the preheating temperature of the die is 450℃-460℃, and the preheating temperature of the extruder is 410℃-420℃. The preheating time is 15-10 min. The extrusion outlet temperature is ensured to be 500℃-510℃, and the bar outlet speed is controlled to be 3.0m / min-4.5m / min. Subsequently, the extruded bar is cooled to 180℃ by online air mist cooling and then air-cooled to room temperature to obtain a bar-shaped raw material.

[0022] According to the above method, the deformation heat treatment process in step (4) is as follows: the rod-shaped raw material obtained in step (3) is preheated to 525-535℃, the mold is preheated to 420-430℃, and then rapidly forged. After forging, the aluminum alloy automotive swing arm forging is placed in a quenching furnace for quenching, wherein the quenching water temperature is 40-50℃. After cooling, the aluminum alloy forging is directly placed in an aging furnace, heated to 190℃, and held for 0.5-1h; then the temperature is lowered to 165℃ and held for 7-9h.

[0023] The beneficial effects of this invention are as follows:

[0024] 1. This invention optimizes the alloy element composition. Si and Mg elements improve the strength and elongation of the material, ensuring the processing performance of the aluminum alloy; Mn and V elements can increase the recrystallization temperature of the material, ensuring the fine microstructure of the alloy product, which is beneficial to further improving the strength and rigidity of the aluminum alloy; Zr and RE elements form finely dispersed precipitates with aluminum, which can ensure the high fracture toughness and high fatigue resistance of the aluminum alloy automotive swing arm forging.

[0025] 2. This invention employs a heat treatment process of quenching and "high temperature short time + low temperature long time" aging to increase the density of the GP zone and nucleation points, promote the formation of a high-density dispersed microstructure in the aluminum alloy, and effectively improve the mechanical properties of the aluminum alloy automotive swing arm forging.

[0026] 3. This invention eliminates the ingot homogenization process of traditional casting, and combines the alloy heat treatment heating and the preheating process of forging, reducing energy consumption and the manpower and material consumption of material transfer, and realizing short-process and low-cost manufacturing of aluminum alloy automotive swing arm forgings.

[0027] 4. The aluminum alloy automotive swing arm forging obtained by optimizing the composition of aluminum alloy materials and through melting, extrusion, deformation and heat treatment processes has excellent properties such as lightweight, high strength, high fracture toughness and high fatigue resistance, and is an effective alternative to automotive swing arms on the market. Detailed Implementation

[0028] The present invention will be further described below with reference to specific embodiments.

[0029] Example 1

[0030] An aluminum alloy material suitable for automotive control arms and its deformation heat treatment process, including the components and properties of the aluminum alloy material.

[0031] The percentage composition is as follows: Si: 0.85%, Fe: 0.15%, Mn: 0.58%, V: 0.10%, Mg: 1.32%, Zr: 0.15%, RE: 0.12%, with the balance being Al and other unavoidable impurity elements. Specifically, Mg + Si = 2.17%; Zr + RE = 0.27%; Mn + V = 0.68%.

[0032] The above-mentioned method for preparing an aluminum alloy material suitable for automotive control arms includes the following steps:

[0033] (1) Smelting: According to the mass percentage, first add pure aluminum, pure magnesium, and aluminum-silicon alloy into the smelting furnace, heat to 720℃ and stir to completely melt the alloy, then add aluminum-iron alloy, aluminum-manganese alloy, aluminum-vanadium alloy, aluminum-zirconium alloy and aluminum rare earth intermediate alloy, continue to heat to 750℃, and stir and take samples to adjust the composition after all alloy elements have melted; adjust the temperature of the aluminum alloy melt to 735℃, spray in refining agent for refining treatment, then heat to 770℃, introduce argon gas for degassing refining, and remove slag after refining; let the refined aluminum alloy melt stand until the temperature of the aluminum alloy melt drops to 735℃;

[0034] (2) Casting: The aluminum alloy melt treated in step (1) is cast into shape by a hot-top casting machine, wherein the casting speed is 90 mm / min, the cooling water pressure is 0.08 MPa, and the temperature of the aluminum alloy melt is maintained at 735℃.

[0035] (3) Extrusion: The aluminum alloy ingot, die, and extrusion press are preheated. The preheating temperature of the aluminum alloy ingot is 480℃, the preheating temperature of the die is 450℃, and the preheating temperature of the extrusion press is 415℃. The preheating time is 18min. The extrusion outlet temperature is ensured to be 500℃, and the bar exit speed is controlled to be 3.0m / min. The extruded bar is then cooled to 180℃ by online air mist cooling and then air-cooled to room temperature to obtain bar-shaped raw material.

[0036] (4) Deformation heat treatment: The rod-shaped raw material obtained in step (3) is preheated to 535℃, and the die is preheated to 430℃, and then quickly forged. After forging, the aluminum alloy automotive swing arm forging is placed in a quenching furnace for quenching, where the quenching water temperature is 45℃. After cooling, the aluminum alloy forging is directly placed in an aging furnace, heated to 190℃, and held for 0.5 hours; then the temperature is lowered to 165℃ and held for 8 hours.

[0037] Example 2

[0038] An aluminum alloy material suitable for automotive control arms and its deformation heat treatment process are disclosed. The components and mass percentages of the aluminum alloy material are as follows: Si: 0.7%, Fe: 0.2%, Mn: 0.65%, V: 0.05%, Mg: 1.35%, Zr: 0.1%, RE: 0.2%, with the balance being Al and other unavoidable impurity elements. Specifically, Mg + Si = 2.05%; Zr + RE = 0.3%; Mn + V = 0.7%.

[0039] The above-mentioned method for preparing an aluminum alloy material suitable for automotive control arms includes the following steps:

[0040] (1) Smelting: According to the mass percentage, first add pure aluminum, pure magnesium, and aluminum-silicon alloy into the smelting furnace, heat to 730℃ and stir to completely melt the alloy, then add aluminum-iron alloy, aluminum-manganese alloy, aluminum-vanadium alloy, aluminum-zirconium alloy and aluminum rare earth intermediate alloy, continue to heat to 755℃, after all alloy elements have melted, stir and take samples to adjust the composition; adjust the temperature of the aluminum alloy melt to 740℃, spray in refining agent for refining treatment, then heat to 780℃, introduce argon gas for degassing refining, and remove slag after refining; let the refined aluminum alloy melt stand until the temperature of the aluminum alloy melt drops to 740℃;

[0041] (2) Casting: The aluminum alloy melt treated in step (1) is cast into shape by a hot-top casting machine, wherein the casting speed is 85 mm / min, the cooling water pressure is 0.07 MPa, and the temperature of the aluminum alloy melt is maintained at 740℃.

[0042] (3) Extrusion: The aluminum alloy ingot, die, and extrusion press are preheated. The preheating temperature of the aluminum alloy ingot is 500℃, the preheating temperature of the die is 455℃, and the preheating temperature of the extrusion press is 420℃. The preheating time is 10min. The extrusion outlet temperature is kept at 510℃, and the bar exit speed is controlled at 4.0m / min. The extruded bar is then cooled to 180℃ by online air cooling and then air-cooled to room temperature to obtain bar-shaped raw material.

[0043] (4) Deformation heat treatment: The rod-shaped raw material obtained in step (3) is preheated to 525℃, and the die is preheated to 420℃, and then quickly forged. After forging, the aluminum alloy automotive swing arm forging is placed in a quenching furnace for quenching, where the quenching water temperature is 4℃. After cooling, the aluminum alloy forging is directly placed in an aging furnace, heated to 190℃, and held for 0.8h; then the temperature is lowered to 165℃ and held for 9h.

[0044] Example 3

[0045] An aluminum alloy material suitable for automotive control arms and its deformation heat treatment process are disclosed. The components and mass percentages of the aluminum alloy material are as follows: Si: 0.9%, Fe: 0.1%, Mn: 0.45%, V: 0.15%, Mg: 1.15%, Zr: 0.2%, RE: 0.1%, with the balance being Al and other unavoidable impurity elements. Specifically, Mg + Si = 2.05%; Zr + RE = 0.3%; Mn + V = 0.6%.

[0046] The above-mentioned method for preparing an aluminum alloy material suitable for automotive control arms includes the following steps:

[0047] (1) Smelting: According to the mass percentage, first add pure aluminum, pure magnesium, and aluminum-silicon alloy into the smelting furnace, heat to 725℃ and stir to completely melt the alloy, then add aluminum-iron alloy, aluminum-manganese alloy, aluminum-vanadium alloy, aluminum-zirconium alloy and aluminum rare earth intermediate alloy, continue to heat to 760℃, after all alloy elements have melted, stir and take samples to adjust the composition; adjust the temperature of the aluminum alloy melt to 730℃, spray in refining agent for refining treatment, then heat to 760℃, introduce argon gas for degassing refining, and remove slag after refining; let the refined aluminum alloy melt stand until the temperature of the aluminum alloy melt drops to 730℃;

[0048] (2) Casting: The aluminum alloy melt treated in step (1) is cast into shape by a hot-top casting machine, wherein the casting speed is 95 mm / min, the cooling water pressure is 0.06 MPa, and the temperature of the aluminum alloy melt is maintained at 730℃.

[0049] (3) Extrusion: The aluminum alloy ingot, die, and extrusion press are preheated. The preheating temperature of the aluminum alloy ingot is 490℃, the preheating temperature of the die is 460℃, and the preheating temperature of the extrusion press is 410℃. The preheating time is 15min. The extrusion outlet temperature is maintained at 505℃, and the bar exit speed is controlled at 4.5m / min. The extruded bar is then cooled to 180℃ by online air cooling and then air-cooled to room temperature to obtain bar-shaped raw material.

[0050] (4) Deformation heat treatment: The rod-shaped raw material obtained in step (3) is preheated to 530℃, and the die is preheated to 425℃, and then quickly forged. After forging, the aluminum alloy automotive swing arm forging is placed in a quenching furnace for quenching, where the quenching water temperature is 50℃. After cooling, the aluminum alloy forging is directly placed in an aging furnace, heated to 190℃, and held for 1 hour; then the temperature is lowered to 165℃ and held for 7 hours.

[0051] Comparative Example 1

[0052] Compared with Example 1, the content of Si element in Comparative Example 1 is 0.80%, the content of Mg element is 1.55%, and the rest is the same as in Example 1.

[0053] Comparative Example 2

[0054] Compared with Example 1, the content of Mn in Comparative Example 2 is 0.70%, the content of V is 0.25%, and the rest is the same as in Example 1.

[0055] Comparative Example 3

[0056] Compared with Example 1, the content of Zr in Comparative Example 3 was 0.18%, the content of RE was 0.18%, and the rest was the same as in Example 1.

[0057] Comparative Example 4

[0058] Compared with Example 1, the aging process conditions in step (5) of Comparative Example 4 are: heat preservation temperature 165℃, heat preservation time 9h, and the rest are the same as in Example 1.

[0059] The table below shows the tensile strength, yield strength, and elongation of the high-conductivity aluminum alloy profiles prepared in Examples 1-3 and Comparative Examples 1-3 of this invention, respectively. The results are as follows:

[0060]

[0061] The aluminum alloy automotive swing arm forgings obtained in Examples 1-3 all exhibit tensile strengths above 360, demonstrating the rationality of the material composition design and preparation process in this invention. Compared to Example 1, Comparative Example 1 has an alloy element content of 0.80% Si, 1.55% Mg, and a total Mg and Si content of 2.35%. The resulting aluminum alloy automotive swing arm forging has lower strength, indicating that the content of Mg and Si elements affects the mechanical properties of the alloy. Furthermore, excessively high Mg content can lead to a tendency for hot cracking in the aluminum alloy. Compared to Example 1, Comparative Example 2 has an alloy element content of 0.25% Mn and 0.25% V. The excessively high Mn and V content leads to an increase in large-size precipitates in the alloy, significantly reducing the tensile strength and yield strength of the aluminum alloy forging. Compared to Example 1, Comparative Example 3 contained 0.18% Zr and 0.18% RE, with a total Zr and RE content of 0.36%. The results indicate that the addition of Zr and RE ensures the alloy's strength, but excessive element content can negatively impact its mechanical properties. Compared to Example 1, Comparative Example 4 used a holding temperature of 165℃ and a holding time of 9 hours, resulting in a lower nucleation point density and consequently, lower strength in the aluminum alloy forging.

[0062] The above description is merely a preferred embodiment of the present invention and is not limited to the invention. It should be noted that those skilled in the art can make other equivalent improvements based on the technical teachings provided by the present invention, all of which can achieve the purpose of the present invention and should be considered within the scope of protection of the present invention.

Claims

1. A method for preparing aluminum alloy materials, characterized in that, The method includes the following steps: (1) Smelting: Each component is added to the smelting furnace according to the mass percentage, melted, refined, slag removed, and allowed to stand to obtain aluminum alloy melt; the components and mass percentages of the aluminum alloy material are: Si: 0.7%-0.9%, Fe: 0.1%-0.2%, Mn: 0.45%-0.65%, V: 0.05%-0.15%, Mg: 1.15%-1.35%, Zr: 0.1%-0.2%, RE: 0.1%-0.2%, 0.2%≤Zr+RE≤0.35%, and the balance is Al and other unavoidable impurity elements; (2) Casting: Casting molten aluminum alloy into ingots; (3) Extrusion: Extruding aluminum alloy ingots to obtain rod-shaped raw materials; (4) Deformation heat treatment: The rod-shaped raw material obtained in step (3) is preheated to 525-535℃, the mold is preheated to 420-430℃, and forging is carried out quickly. After forging, the aluminum alloy automotive swing arm forging is placed in a quenching furnace for quenching. The quenching water temperature is 40-50℃. After cooling, the aluminum alloy forging is directly placed in an aging furnace and heated to 190℃ for 0.5-1h. Then the temperature is reduced to 165℃ and held for 7-9h.

2. The method according to claim 1, characterized in that, The smelting process in step (1) is as follows: according to the mass percentage, pure aluminum, pure magnesium, and aluminum-silicon alloy are first added to the smelting furnace, heated to 720-730℃ and stirred to completely melt the alloy. Then, aluminum-iron alloy, aluminum-manganese alloy, aluminum-vanadium alloy, aluminum-zirconium alloy and aluminum rare earth intermediate alloy are added, and the temperature is further raised to 750-760℃. After all the alloy elements have melted, the mixture is stirred and sampled to adjust the composition. The temperature of the aluminum alloy melt is adjusted to 730-740℃, and a refining agent is sprayed in for refining. Then, the temperature is raised to 760-780℃, and argon gas is introduced for degassing and refining. After refining, the slag is removed. The refined aluminum alloy melt is left to stand until the temperature of the aluminum alloy melt drops to 730-740℃.

3. The method according to claim 1, characterized in that, The casting process in step (2) is as follows: The casting process of step (2) involves... (1) The treated aluminum alloy melt is cast into shape by a hot-top casting machine, wherein the casting speed is 85-95 mm / min, the cooling water pressure is 0.06-0.08 MPa, and the temperature of the aluminum alloy melt is maintained at 730-740℃.

4. The method according to claim 1, characterized in that, In step (3), the extrusion process is as follows: the aluminum alloy ingot, the die, and the extruder are preheated. The preheating temperature of the aluminum alloy ingot is 480℃-500℃, the preheating temperature of the die is 450℃-460℃, and the preheating temperature of the extruder is 410℃-420℃. The preheating time is 15-10 min, ensuring that the extrusion outlet temperature is 500℃-510℃ and controlling the bar outlet speed is 3.0m / min-4.5m / min. Then, the extruded bar is cooled to 180℃ by online air cooling and then air-cooled to room temperature to obtain a bar-shaped raw material.

5. An aluminum alloy material suitable for automotive control arms, prepared according to any one of claims 1-4, characterized in that, The components and their mass percentages of the aluminum alloy material are as follows: Si: 0.85%, Fe: 0.15%, Mn: 0.58%, V: 0.10%, Mg: 1.32%, Zr: 0.15%, RE: 0.12%, with the balance being Al and other unavoidable impurity elements.

6. An aluminum alloy material suitable for automotive control arms, prepared by the method according to any one of claims 1-4, characterized in that, In the aluminum alloy material: Mg+Si≤2.2%.

7. An aluminum alloy material suitable for automotive control arms, prepared by the method according to any one of claims 1-4, characterized in that, In the aluminum alloy material: 0.5% ≤ Mn + V ≤ 0.75%.

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