| 摘要 |
PROBLEM TO BE SOLVED: To provide a friction stir welding method that satisfies desired strength without generating post-weld voids, while improvement in productivity or reduction in weight is contrived. SOLUTION: The friction stir welding method performs T-shaped butt-welding by installing, on one surface of a first structural member 5, a groove 7 having a width w7 larger than the thickness t6 of a second structural member 6, by assembling the second structural member 6 into this groove 7 and by inserting, from the other surface 5a of the first structural member 5, a probe 3 projectingly provided at the tip end of a rotor 2 so as to carry out friction stirring. In this friction stir welding method, for the purpose of making the material of the stirred structural members 5, 6 plastically flow to fill a space S between the first and the second structural member 5, 6 in the groove 7, the diameter D of the rotor 2 in a shoulder 4 is set not less than 2.5 times as large as the diameter d of the probe 3, and also, the inclinationθof the probe 3 is set at 3 deg. or larger against the perpendicular of the surface near the friction-stirring part of the first structural member 5. |
