DSWで作製した異材接合体の疲労破壊に及ぼすフレッティングの影響

抄録

Dimple Spot Welding (DSW) is a novel method for dissimilar metal joining, which has been developed for advance multi-materialization of automotive body structure. In this study, fatigue tests were performed for DSW dissimilar metals joints of steels and aluminum alloys. In fatigue tests, all specimens were failed in aluminum alloy plate, and the fatigue life was determined by the strength of the base material used for aluminum alloy plate. As a result of observation of the failed aluminum alloy plate, black wear mark was formed near the crack initiation point, which suggested that the fatigue failure of the DSW joint was affected by the fretting fatigue damage caused by the contact between the steel plate and the aluminum alloy plate. For comparison, the same tests were also performed for SPR (Self-Pierce Riveting) dissimilar metals joints of steels and aluminum alloys. It was found that the fatigue strength was higher in the DSW joint compared with the SPR joint.