With the increasingly stringent requirements of energy security and environmental protection, automobile energy saving and emission reduction has become an important strategy for the future development of China’s automobile industry. In the overall plan for automobile development in made in China 2025, it is emphasized that lightweight is the core technology of energy-saving and new energy vehicles. The key areas of automobile lightweight work include the promotion and application of lightweight design of aluminum alloy, magnesium alloy, high-strength steel, plastic and non-metallic materials and core components.
Aluminum alloy is the leader of lightweight materials. Aluminum alloy auto parts can effectively reduce the weight of the whole vehicle, reduce fuel consumption and increase the range of the vehicle, taking into account the quality, cost and safety of the vehicle. Tesla Model s uses a large number of aluminum alloy materials. The application proportion of Weilai es8 aluminum alloy materials is as high as 96.4%, the weight of the body is only 335Kg, and the aluminum consumption of the new Audi A8 is as high as 58%. The front and rear shock absorption towers and torsion boxes are made of aluminum alloy castings, the front and rear longitudinal beams are made of aluminum alloy profiles, and the floors and front coamings are made of aluminum alloy plates. With the development and progress of China’s automobile industry, the manufacturing, connection and coating process of aluminum alloy parts is becoming more and more mature, and it is widely used in key parts of car body.
Major OEMs and supply chains began to explore lightweight body technology early. The main technical routes include optimization of body structure design, selection of lightweight materials and application of advanced manufacturing technology. As a kind of light alloy, aluminum alloy has the advantages of good formability, service performance and friendly environment. Aluminum alloy has the following advantages: aluminum alloy material is rich in resources and one of the most widely distributed and reserved elements in the earth’s crust; aluminum alloy has small density (about 2.7g / cm3), high specific strength; aluminum alloy is easy to oxidize, with dense oxide film on its surface, good corrosion resistance; good formability, suitable for casting, extrusion, forging and stamping processes; high energy absorption, Improve vehicle crash safety performance; easy to recycle and regeneration, friendly to the environment. Due to these advantages of aluminum alloy, in recent years, the application of aluminum alloy in car body has increased year by year, and the application weight ranks the second, only second to steel.
The aluminum alloy vacuum die-are used to apply the key connection parts of the body, the extruded profiles are used as the main body structure, and the sheet stamping parts are used as the body structure parts. Combined with the structural topology optimization technology, the thin-walled, hollow and integrated design of the body parts are realized. On the premise of ensuring that the strength, rigidity, mode, fatigue and safety performance of the body meet the design and use, the maximum limit is achieved To achieve lightweight body. The application of aluminum alloy in the body also challenges the manufacturing process and cost. Only by comprehensively balancing the body weight, part cost, manufacturing risk, development cycle and other factors, increasing the investment in research and application of new technology, and continuous innovation, can we achieve a comprehensive breakthrough in the cutting-edge technology of body lightweight.