Friction stir welding method

Abstract

On a main shaft 30 of a numeric control type machine tool, a rotary tool 50 is installed. The main shaft 30 is not inclined in the machine tool. A first member 70 and a second member 76 to be subjected to friction stir welding are fixed on a table 20. Relative to an axial center of the rotary tool 50, a non-linear welding portion of the first member 70 and the second member 76 is inclined by inclining the table 20. Then, by rotating the table 20 and relatively moving the portion to be welded into contact with the rotary tool 50, welding of the first member to the second member is carried out according to friction stir welding. The above-stated inclination is the inclination required for the friction stir welding. In this way, welding along a path of ring shape or circular shape (including a circular arc) using friction stir welding can be carried out easily.

What is claimed is:  
     
         1 . A weld body, comprising: 
 a first member and a second member joined to each other in a ring shape by a friction stir welding;    the friction stir welding is carried out from a side of one face of said first member; and    by continuing a portion in which the friction stir welding had been carried out, in a radial direction to an outer side of said ring shape members, the weld body has a portion which is welded according to a second friction stir welding; and    an end portion of said portion which is welded according to the second friction stir welding is positioned adjacent an end face of a radical direction outer side or a radial direction inner side of said first member or said second member.