1, Raw material preparation: selection and preparation of aluminum ingots
The first step in automotive aluminum processing is to select suitable aluminum ingots as raw materials. The commonly used aluminum ingots include Al Si Mg alloy ingots, with the American standard model A356.2 and the Chinese standard ZL101. This alloy has good casting and mechanical properties, making it very suitable for the production of automotive parts. In addition, some manufacturers choose pure aluminum ingots and adjust the composition according to specific needs to meet casting requirements.
The preparation process of aluminum ingots includes multiple steps such as aluminum melting, casting, and cooling. During the smelting process, it is necessary to strictly control parameters such as aluminum composition, temperature, and pouring speed to ensure the quality of aluminum ingots. High quality aluminum ingots are the foundation of subsequent processing, directly affecting the performance and quality of the final components.
2, Mold design and manufacturing
Mold is an indispensable tool in the aluminum alloy casting process. Compared to casting molds such as engine or motor casings, the structural design of aluminum alloy wheel molds is relatively simple, mainly due to their demolding structure, cavity complexity, and exhaust and gas storage structure characteristics. Mold design is usually provided by automobile manufacturers with parameters such as wheel shape, load, weight, etc., and then carried out by the design department of the wheel company for specific design. After the design is completed, it is continuously optimized through software simulation until it meets the requirements of the host factory.
The manufacturing of molds requires high-precision processing equipment and techniques to ensure the accuracy and durability of the molds. High quality molds can not only improve casting efficiency, but also ensure the dimensional accuracy and surface quality of components.
3, Aluminum Melting and Casting
Before the casting process, it is necessary to melt the aluminum ingot and mix its components. The smelting process is usually carried out in a melting furnace, using gas as the heat source. After melting, purification treatment of the aluminum liquid is also required to remove impurities.
Casting is a crucial step in the formation of raw materials. The commonly used casting methods in automotive aluminum processing include low-pressure casting and gravity casting. Low pressure casting is the process of pouring melted aluminum liquid into a casting insulation furnace, gradually filling the mold cavity and solidifying it into shape by controlling the pressure. Gravity casting is the process of utilizing the gravitational force of aluminum liquid to flow into the mold cavity and solidify. During the casting process, it is necessary to ensure the correct solidification sequence of the aluminum liquid to ensure the internal structure and performance of the product.
4, Wheel rim spinning and heat treatment
After the casting is completed, some aluminum alloy wheels will undergo wheel rim spinning process. This process further enhances the performance of the wheel rim through rotation and compression, making it more sturdy and durable. Wheel spinning is mainly used in the manufacturing of wheels for mid to high end car models.
Heat treatment is an important means to improve the performance and strength of aluminum alloy components. The commonly used heat treatment processes include T6 heat treatment, etc. By heating the blank to a certain temperature, holding it for a certain period of time, and then cooling it at a certain speed, the mechanical properties and corrosion resistance of aluminum alloy can be significantly improved. During the heat treatment process, it is necessary to strictly control the furnace temperature and rolling rod speed to ensure that each blank can receive sufficient heat treatment.
5, Machining and Inspection
Machining is the process of processing the cast blank to the size and shape required by the customer. This process is usually carried out through CNC machining centers, including cutting, trimming, and other processes. Machining requires high dimensional accuracy, especially for assembly dimensions such as tires, center holes, bolt holes, etc. The debris generated during the cutting process can be recycled and reused, and returned to the smelting step for re production.
After machining is completed, strict inspection of the components is required. The inspection content includes multiple aspects such as dimensional accuracy, surface quality, internal defects, etc. Only components that have passed inspection can proceed to the next process.
6, Painting and Packaging
Painting is an important step in improving the appearance and anti-corrosion performance of aluminum alloy components. By spraying coatings, components can be protected from corrosion and wear. The type and thickness of the coating will affect the price and quality of the product. Common coating materials include epoxy resin, polyurethane, etc.
After the painting is completed, the components need to be packaged. Packaging materials should have good protective and moisture-proof properties to ensure that components are not damaged during transportation and storage.
