| 摘要 |
PROBLEM TO BE SOLVED: To provide a friction stir welding method capable of increasing the welding strength of a lap joint. SOLUTION: A welding tool (1) includes a small diameter projected part (2) at the tip of a shoulder (3). The welding tool is press-fitted only to the upper plate (4) of the lap joint while being rotated. By a friction stirring action, an upper plate side welding boundary surface (6) plastically flows, a surface oxidation film on a lapped surface is peeled off, and the boundary surface is activated to provide an excellent welding part. Also, since the welding tool is formed in a shape having the small diameter semispherical projected part (2) at the tip thereof, the thickness (12) of an upper plate welding part is increased, and a lap joint part with high welding strength can be provided. COPYRIGHT: (C)2009,JPO&INPIT
|
