FRICTION STIR WELDING METHOD SUITABLE FOR COMBINING MEMBERS INCLUDING VARIOUS MATERIALS AND PREVENTING DENT OF JOINING PORTION

摘要

PURPOSE: A friction stir welding method is provided to prevent formation of a dent in a joining portion between joined members by means of a friction stir welding method. CONSTITUTION: A friction stir welding method comprises a step of providing an abutting portion by making the end of a first extrusion frame member(50) abutting on the end of a second extrusion frame member(60) and a step of providing a protruding portion(55) protruding in the thickness direction of the first extrusion frame member to the end of the width direction of the first extrusion frame member. The end of the second extrusion frame member abuts on the end of the width direction of the first extrusion frame member. A protruding piece superposed on the end of the second extrusion frame member is formed by extending toward the second extrusion frame member from the apex of the protruding portion. A rotating tool(70) is rotated and the rotating tool is moved relatively along the abutting portion in a state wherein the rotating tool is inserted in the protruding portion and the abutting portion from the protruding portion side to execute friction stir welding.