ROTATION TOOL

摘要

A friction stir welding tool (1) is provided which allows for excellent wear resistance and high joining strength even in a process of joining difficult-joining materials. A friction stir welding tool (1) of the present invention is used for a friction stir welding process and includes a base material (4). The base material (4) includes a hard phase and a binder phase. The hard phase includes TiCN. The binder phase is made of an iron group metal. A mass ratio B s of the binder phase to the base material (4) in a region having a thickness of 20 µm from a surface of the base material (4) is smaller than a mass ratio B i of the binder phase to the base material (4) in a region beyond the thickness of 20 µm from the surface of the base material (4).