Study on the crystallisation of amorphous alloy–titanium alloy joints during different welding processes

In this study, continuous laser beam welding (CLBW) and tungsten-inert-gas (TIG) welding were employed to weld β-Ti dendrite-toughened metal glass composite with TC4 titanium alloy. The microstructure, element distribution, and mechanical properties of the welded joints were studied. The influence of the welding heat source state and welding speed on the crystallisation of the joints was analysed. The results revealed that at the interface between the fusion zone (FZ) and the Ti alloy, columnar crystals of β-Ti grew positively and extended from the Ti alloy into the FZ. The development of β-Ti grains was more pronounced during TIG welding than during CLBW owing to the lower cooling rate of the liquid pool in TIG welding. The hardness in the FZ of the TIG-welded sample was lower than that of the CLBW sample.