2018 年 36 巻 3 号 p. 185-192
Two types of plates, which was cut parallel to the extrusion direction (0°specimen) and perpendicular to the extrusion direction (90°specimen), were prepared for ultrasonic spot welding. After welding, the tensile strength and microstructure of the joints were investigated. For the joints of 0°specimens, the strength was high and the dispersion of its strength was small. In contrast, the joints of 90°specimens were remarkably unstable in strength. To promote the plastic flow at the interface, we put a Mg film as an insert metal between the Mg-Zn-Y plates. After welding of the joints of 90°specimens with the insert metal, we found that the joins were stable in strength. It was revealed that, during the welding, the temperature of the joints with the insert metal was increased compered to the joints without the insert metal.