Fatigue characteristic in non- combustible magnesium alloy dissimilar materials joint with different combination of upper plate / lower plate materials

Abstract

Using non-combustible magnesium alloys for structural materials contributes to weight reduction in transportation equipment. Therefore, appropriate joining method for non-combustible magnesium alloy with high reliability is necessary. Self-Piercing Rivet (SPR) joint has been widely applied to joining aluminum alloys and is suitable for joining of dissimilar metals. In this study, SPR joint was applied to a non-combustible magnesium alloy AX41, and fatigue strength properties of AX41 similar material joint and dissimilar materials joints with AA6061 and SPCC were evaluated. The dissimilar material joints exhibited higher fatigue strength compared to AX41 similar material joint. Depending on the combination of the upper and lower plate materials, cracks may occur during the joining process, and fatigue properties may be affected. Regardless of the plate materials combination, stiffness of a plate is considered to have a significant effect on fatigue strength of SPR joint because deformation of upper and lower plates has an effect on fatigue mechanism.