Patent ID: 9566661
Date: 2017-02-14
CPC Classifications: B23K

Claim:
1. A method of friction stir welding for joining two metal members together using a rotary tool including a stirring pin, comprising: a butting step for butting the metal members which are to be joined against each other thereby forming a butting portion; and a primary joining step for inserting the stirring pin in a rotating state into the butting portion of the metal members and carrying out friction stir welding with only the stirring pin contacting with the metal members with generating frictional heat, wherein before the primary joining step, the metal members are placed on a platform of a friction stirring apparatus, and are unmovably fixed using a jig for clamping, wherein in the primary joining step, a stepped portion is formed around a plasticized region on a front surface of the metal members along a movement path of the rotary tool, and wherein a screw sectional area, a summation of sectional areas of regions surrounded by a spiral groove and an imaginary line extending along an outer circumferential surface of the stirring pin, is 30 to 280 mm