车用轻量化材料现状及发展趋势

Present Situation and Development Trend of Automotive Lightweight Materials

金属材料是汽车轻量化的主要发力方向,但非金属材料在提高产品性能、减低产品重量方面也起到了一定的作用,如聚丙烯、纤维增强复合材料、陶瓷。对车用金属轻量化材料的应用现状与发展趋势进行了重点分析。高强度钢是车体材料中最重要且用量最大的材料,能够减低厚度,提高结构件的承载力与防撞能力,而且价格低廉,具有突出的可焊接性、可重复利用性。铝合金的抗拉强度和抗疲劳性能良好,在碰撞试验中具有更为突出的安全性,但铝合金现阶段生产成本较高。镁合金是车身用金属材料中最轻的,密度低,具有良好的减震性、导电性、导热性、压铸性。但其抗拉强度、抗疲劳强度、弹性模量均不如铝合金,而且镁合金比铝合金更容易被氧化腐蚀。在汽车轻量化方面,高强度钢、铝合金、镁合金等轻质金属材料已有了完整的商业应用,但针对不同档次、不同用途、不同性能要求的汽车产品,还需要大力将轻量化技术向中低端车型普及,降低轻量化零件的成本。

Metal material is the main orientation of automobile lightweight,and the non-metallic material has played certain function in improving product performance and lighting product weight,such as polypropylene,fibre reinforced composite material and ceramics.We analyze the application situation and development trend of automotive metal lightweight materials.High-strength steel is the most important and the maximal dosage necessary material of automotive material.It can not only reduce thickness,improve bearing capacity and collision avoidance ability of structural components,but also it is cheap,and is featured by outstanding weldability and reutilization.Strength of extension and anti-fatigue performance of aluminium alloy are good.It is featured by the prominent safety in crash test,but the production cost is relatively high.Magnesium alloy is the lightest among the metallic materials of the car body,with low density,good damping,electrical conductivity,thermal conductivity and pressure casting characteristics.But it is not better than aluminium alloy in the aspects of strength of extension,fatigue resistance and elasticity modulus;and it is easier to be oxide etched than aluminium alloy.In the aspect of automotive metal lightweight,high-strength steel,aluminium alloy and magnesium alloy have already been widely applied in business.But according to automobile products of different levels,uses and performance requirements,it is necessary to popularize lightweight technology application in mid-low end motorcycle type,and reduce the cost of lightweight components.