A review on mechanical joining of aluminium and high strength steel sheets by plastic deformation

Mechanical joining processes by plastic deformation such as self-piercing riveting, mechanical clinching and hemming for aluminium alloy and high strength steel sheets are reviewed. These mechanical joining processes without metallurgical bonding such as welding have the advantages of high productivity, low cost, application to multi-materials, etc. To join the aluminium alloy and high strength steel sheets having low ductility and high strength, die shapes in self-piercing riveting and mechanical clinching are optimised, and the interlock is formed by controlling plastic deformation. The static and fatigue strengths of self-piercing riveting are considerably higher than those of resistance spot welding, and the fatigue strength of mechanical clinching is similar to that of resistance spot welding. In self-piercing riveting, aluminium rivets having high recyclability and joining of multiple sheets are explained. Although hemming is mostly employed for joining of outer body panels having high ductility, the application to body-in-white structural components requiring high strength becomes possible due to hemming of high strength steel sheets.