| 摘要 |
In a friction stir welding method, a pair of plate materials is arranged opposing one another such that the ends thereof are butted together, after which friction stir welding is performed. A first shoulder is arranged at one surface of the pair of plate materials and a second shoulder is arranged at the other surface of the plate materials to sandwich therebetween a joint to be formed by friction stirring of the end parts of the plate materials, and the first shoulder and the second shoulder are rotated, thereby friction stirring the joint of the pair of plate materials. As the joint is friction stirred, the first shoulder and the second shoulder are moved from the other surface toward the one surface of the plate materials, thereby forming at the joint a protruding part protruding from the one surface of the plate materials as the friction stir welding is performed. |
