Abstract: At the present stage, many new energy vehicles carried power batteries which are installed on the side sill beam. When the new energy vehicle encounters a side collision, it may lead to extremely dangerous accidents such as fire and explosion of the power battery in addition to causing injury to the personnel in the vehicle. Therefore, it is particularly important to improve the strength and energy absorption of the side sill beam of new energy vehicles. Aluminum alloy side sill beam with high strength and multi-stage energy absorption performance adopts the unique aluminum alloy formula from the raw material. The process procedure refines the alloy grain, and the innovative "目" shaped section structure is designed, so as to realize the timely collapsing and deformation during the collision process and absorb energy step by step by side sill beam,avoid transferring the collision energy to the structure inside and behind the vehicle. It not only realizes the lightweight of new energy vehicles, but also protects the safety of people and battery packs in limited space to the greatest extent. It can be widely used in the field of new energy vehicles,effectively promoting the technological progress and industrial upgrading for the new energy vehicle industry.

Key words: Aluminum alloy side sill beam; High strength; Lightweight; Multi-stage energy absorption; Grain refinement

摘要： 现阶段很多新能源汽车搭载的动力电池都安装在汽车门槛梁上，当新能源汽车发生侧 碰时，可能会引起除对车内人员造成伤害外，还会引起动力电池起火爆炸等极限事故。因此， 如何提高新能源汽车门槛梁的强度及吸能作用就显得尤为重要。高强度多级吸能的汽车铝合 金门槛梁从原材料开始采用独特的铝合金配方，工艺过程细化合金晶粒，创新的“目”字形 截面结构设计，实现这种铝合金门槛梁在碰撞过程中及时溃缩变形并逐级吸能。避免将碰撞 时的全部能量直接传递给车内及车身后的结构。既实现了新能源汽车的轻量化，又在有限空 间内最大程度地保护了车内人员及电池组的安全。可广泛应用于新能源汽车领域，有力推动 新能源汽车行业技术进步和产业升级。

关键词: 铝合金门槛梁；高强度；轻量化；多级吸能；细化晶粒