Patent ID: 8220694

Claim:
A friction stir welding method, comprising: providing a joining tool comprising a friction surface; providing a first workpiece comprising a first treating layer, and a first joining surface slanted to the first treating layer; providing a second workpiece angled to the first workpiece, the second workpiece comprising a second treating layer, and a second joining surface slanted to the second treating layer; providing a joining member with a melting point lower than that of the first workpiece and the second workpiece; arranging the joining member at a joining portion of the first joining surface of the first workpiece and the second joining surface of the second workpiece, and abutting the first joining surface of the first workpiece and the second joining surface of the second workpiece, wherein the first workpiece defines a first groove from the first joining surface, and the second workpiece defines a second groove from the second joining surface, the first groove of the first workpiece and the second groove of the second workpiece cooperatively define a receiving slot receiving the joining member; positioning the friction surface of the joining tool to resist at least one of the first treating layer and the second treating layer; and rotating and moving the joining tool to agitate at least one of the first workpiece and the second workpiece, until at least part of the first workpiece and the second workpiece are plasticized and joined together.