镁合金自冲铆连接技术研究现状

Research status of self pierce riveting technology of magnesium alloy

镁合金具有密度小、比强度高等优点,在汽车车身中的应用越来越受到重视,能实现汽车轻量化。自冲铆作为一种机械连接技术已被广泛用于汽车结构中的铝合金、异种材料的连接。然而,镁合金的自冲铆连接比较困难因为室温下镁滑移系少、延展成型性能差。为了抑制裂纹在镁合金自冲铆连接中生成、改善镁合金自冲铆连接接头性能,最近开发了激光辅助加热、原位感应加热镁合金自冲铆连接技术。主要介绍了辅助加热自冲铆连接工艺方法的提出背景、工艺特点以及所得到焊接接头的主要性能。

In order to reduce weight of a vehicle,application of magnesium alloy has increased due to its low density and high specific strength. Self pierce riveting（SPR）as mechanical joining is widely used for aluminum alloy or dissimilar materials in vehicle structures. However,it is difficult to joint magnesium sheets by SPR due to less ductility from a limitation of slip at room temperature.Laser assisted SPR and in-situ heating SPR joining process have been developed to improve reliability of magnesium alloy joint,and to prevent occurrence of cracks. The background,technological characteristics and main performances of the joint are introduced mainly in this paper.