Weldability of Zr50Cu30Al10Ni10 bulk glassy alloy by small-scale resistance spot welding

A Zr-based metal glassy alloy was successfully welded by small-scale resistance spot welding (RSW). Transmission electron microscopy as well as X-ray diffractometry indicated that no crystallization occurred in both the weld nugget and the heat-affected zone. Moreover, no structural relaxation occurred, resulting in good joint quality, that is, high strength and good ductility. The morphology of the weld metal expulsion was different from that of other conventional metals, and it appears to have formed in the supercooled liquid state. The approximate cooling rate and the maximum temperature at the electrode/sheet and the faying interfaces were estimated. A sufficiently high cooling rate required for glass formation was obtained by small-scale RSW.