| 摘要 |
PROBLEM TO BE SOLVED: To provide a friction stir welding method capable of prolonging the lifetime of a rotating tool, and a method for manufacturing an underframe of a railroad vehicle.SOLUTION: In the friction stir welding, a probe part 14 of a rotary tool 11 provided with a columnar body part 12 having ceramics and the probe part 14 having projecting ceramics at a center part of a fore end of the body part 12 is pushed into butted parts P of 7N01 materials 2, 2 specified in JIS H 4100, and the butted parts P are joined with each other by rotating the rotary tool 11. The deformation resistance of this material is higher than that of Al alloys such as 6N01 material, and in the friction stir welding of 7N01 material 2 in which the rotary tool 11 is easily worn, the lifetime of the tool is prolonged and the joining at high joining rate becomes possible by using the ceramic-made rotary tool 11 having excellent wear resistance. |
