Joining method and apparatus using frictional agitation

Abstract

A projection 3 is pressed into first and second members W1 and W2 with a predetermined pressure, while rotating a rotary tool 1 at a preset rotational speed, such that the first and second members W1 and W2 are sandwiched by the rotary tool 1 and stationary tool 10. The projection 3 rotates in these members to cut member textures around it, thereby generating heat. Furthermore, the cuttings formed by cutting with the projection 3 are accumulated in the members and agitated by the two tools 1 and 10, to collide against the surrounding member textures and the projection 3, thereby generating heat. Also, a first shoulder 2 is pressed in with a predetermined pressure and rotated to generate heat, thereby fusing the cuttings. While the plastic flow of the surrounding member textures is promoted, the first shoulder 2 is held at the predetermined pressure and rotational speed. The pressure per unit area is thus increased to increase the volume of plastic flow. When the rotary tool is pulled out while being rotated, the member textures that have been plastically flowing are cooled and joined to each other.

Dependencies are inferred from the claim text.