Progress in automobile body processing technology: multi-material and lightweight strategies for saving energy and reducing emissions

The automobile industry is an important pillar of the national economy. In response to the increasingly serious problems of energy depletion and environmental pollution, saving energy consumption and reducing pollutant emissions have become urgent requirements for the automotive industry. The most important solution at present is to reduce the weight of the car body through the application of new and multiple materials. As far as the structural materials of automobiles are concerned, they have been developed from traditional steel and aluminum to high-strength steel, high-strength aluminum alloy, fiber-reinforced polymer matrix composite (PMC), ceramic matrix composite (CMC), and other new materials. The advancement of materials and processing methods has greatly contributed to the overall safety and performance improvement of vehicles. However, the main challenges faced by the automobile industry during this transition include higher manufacturing costs for new materials, lower production efficiency, and greater difficulty in material recycling. Correspondingly, in this review, we try to explore the processing methods that have been improved in recent years and outlook the challenges that the automobile industry is facing.