| 摘要 |
PROBLEM TO BE SOLVED: To provide a friction stir welding method in which good welding can be performed easily even in a case that a work-piece has thickness variation.SOLUTION: A friction-stir tool includes a first shoulder face contacting a work-piece, a second shoulder face which is arranged to face the first shoulder face and contacts the rear surface of the work-piece, a shank part which fixes the spacing between the first shoulder face and the second shoulder face and connects them, and a groove part which is formed at least at one of the first shoulder face and the second shoulder face and, in the first shoulder face or the second shoulder face, extends to the tool rotation direction forward side as proceeding to the outer peripheral side and opens at the outer peripheral side edge, and applies friction stir welding to the work-piece by rotating around the axis line of the shank part in a specified tool rotating direction. A friction stir welding method comprises the steps for determining the minimum allowable dimension of the work-piece thickness and applying friction stir welding to the work-piece, by using the friction-stir tool. |
