To provide a joining method which can carry out friction stir welding to the butted portion of metallic members from the front face side and the back surface side of the metallic members, and also can improve the tightness and the water tightness of the metallic members.
The present joining method includes: a butting step for forming a joining metallic member 1 by butting end faces of a pair of metallic members on each other; a first final joining step for carrying out the friction stir welding to the joining portion J1 of the joining metallic member 1 from its front face A side; a second final joining step for carrying out the friction stir welding to the joining portion J1 from the back surface B side of the joining metallic member 1; and a welding joining step for carrying out welding to the joining portion J1 from the side surface side of the joining metallic member 1. The joining method is characterized in that a front face side plasticized region W1 formed in the first final joining step and a back surface side plasticized region W2 formed in the second final joining step are overlapped and that, in the welding joining step, these regions W1, W2 are hermetically sealed with weld metal.
HORI HISASHI
KAWAMOTO TOMOHIRO
AOKI KAZUO
Etsuo Tada
Nosho Machida