Laser welding of annealed Zr55Cu30Ni5Al10 bulk metallic glass

Laser welding is one of the promising ways for manufacturing metallic glass products with complicated shape and geometry. In this work we focus on the effect of annealing treatment and welding parameters on laser welding of annealed Zr55Cu30Ni5Al10 bulk metallic glass as intended and unintended heat treatment occurs in the process. We find that laser welding can produce well welded specimen plates with no obvious welding defects in the joints and high welding speed may lead to better joints. Although higher annealing temperature or longer annealing time leads crystallization, bulk metallic glass material still remains largely amorphous in the heat affected zone. Compared with the welded joint without annealing, the micro-hardness and bending strength are enhanced due to the presence of the nanocrystals occurred in annealed welding joint. Therefore, appropriate annealing treatment with the annealing temperature near the glass transition temperature and annealing time as long as that in hot embossing of BMG parts may play a beneficial role in laser welding of metallic glasses. •We investigate the laser welding of annealed Zr55Cu30Al10Ni5 bulk metallic glass.•We analyze the effect of welding speed and annealing on the laser welding.•The high speed facilitates better joint based on the penetration bead.•Annealing can suppress crystal growth and hence leads to nanocrystallization.•Annealing of BMG samples prior to welding can improve the properties of the joints.