With the increasing global attention to environmental pollution, automobile enterprises have carried out the research and development of new materials and new technologies around lightweight. Automobile lightweight has become an important direction of development. The research shows that 60% of automobile energy consumption comes from the self weight of automobile. When the weight of automobile equipment is reduced by 10%, the corresponding fuel consumption can be reduced by 6% ~ 8%. At the same time, lightweight can also improve the braking performance of the vehicle to a certain extent, making the vehicle a safer, comfortable and environmentally friendly means of transportation. Aluminum alloy material has become the preferred material for automobile lightweight because of its light weight, high specific strength, easy processing and good corrosion resistance.
As a key part of the vehicle chassis structure, the rear subframe plays the role of supporting the front and rear axles and suspension, and can significantly improve the driving controllability, riding safety and comfort. At the same time, the reduction of the rear subframe's own mass can enhance the bearing performance of the whole vehicle, which is of great significance in improving the handling and stability of the vehicle. Therefore, The selection of rear subframe materials is very important to improve the performance of the whole vehicle. The traditional rear subframe is mostly made of steel plate, and only a few models use aluminum alloy subframe.
The structure of the rear subframe of a vehicle model is shown in the figure below. It is made of aluminum alloy. Through reasonable structural design and systematic process flow, it is formed by low-pressure integrated casting to obtain the rear subframe that meets the requirements of strength and durability and improve the lightweight level of the whole vehicle. The overall dimension of the rear subframe is 1 165 mm × 798 mm × 396 mm, with an average wall thickness of 5 mm and a mass of 30.5 kg. It is a large complex thin-walled part with high strength, high toughness and corrosion resistance. Compared with steel parts, it can reduce the weight by 10.1 kg and the weight reduction ratio is about 33%.