FRICTION STIR WELDING METHOD AND DEVICE, AND TOOL SET

摘要

In order to perform highly-reliable friction stir welding superior in terms of economy and high in joint strength, a rotary tool 3 includes a tool body 3a having a shoulder surface 3b formed at a tip end portion thereof and a protruding portion 3d formed so as to protrude from the shoulder surface 3b, a backing tool 4 includes a tool body 4a having a pressing force maintaining surface 4b formed at a tip end portion thereof and a recessed portion 4d for receiving a tip end of the protruding portion 3d; the rotary and backing tools 3 and 4 are arranged in opposed relationship on the front and back surface sides of a joint portion J of metal plates; under the state that the backing tool 4 is held, the rotary tool 3 is moved in a direction to approach the backing tool 4 while being rotated; the tip end of the protruding portion 3d of the rotary tool is inserted into the recessed portion 4d of the backing tool 4; the joint portion is sandwiched; the shoulder surface 3b of the rotary tool is pressed against the front surface of the joint portion; and under that state, the rotary tool 3 and the backing tool 4 are moved along the joint portion, and the rotary tool 3 frictionally stirs the joint portion in the entire region in a thickness direction of the plates.