Abstract
Recently, non-equiatomic Ti-Nb-Mo-Ta-W alloy has been proposed as a refractory high-entropy alloy that suppresses elemental
segregation designed using a thermodynamic calculations and empirical parameters. In this study, we purposed to investigate
the effect of rapid solidification by laser irradiation for metal 3D printing on the microstructure formation of this alloy. Thermal
diffusion simulation result showed that both temperature gradient （G） and solidification rate （R） during solidification after laser
irradiation were extremely high compared to those during solidification by conventional methods. In the melt-pool, a dendritic or
cellular microstructures with the size of submicron order were formed along the normal direction of the melt-pool edge, which was
finer in size than the microstructure formed by arc melting. These findings suggest that laser irradiation for metal 3D printing has a
benefit in the refinement of microstructure.
