Abstract
Friction stud welding and friction hydro pillar welding were done with various aluminum alloys using a continues drive friction welding machine. The relation of friction hydro pillar weldability with movement phenomenon of the rotational plane in the friction stud welding were examined. As a result, it became clear that friction hydro pillar weldability was good as for the aluminum alloy that amount of movement of the rotational plane was large, and the aluminum alloy that amount of movement of the rotational plane was small had bad friction hydro pillar weldability.
