Regular eutectic and anomalous eutectic growth behavior in laser remelting of Ni-30wt%Sn alloys

Ni-30wt%Sn alloy powder beds were remelted using a laser beam to examine regular eutectic and anomalous eutectic growth behavior. The remelted microstructure mainly consisted of primary α-Ni dendrites and refined regular lamellar eutectic in the interdendrite space. At the top of the molten pool, the competition between primary α-Ni dendrites and the regular lamellar eutectic can be explained by the maximum interface temperature criterion. Anomalous eutectic was observed at the bottom of the molten pool. The remelting of primary α-Ni dendritic arms formed in the first laser remelting scan had an important effect on the formation of the anomalous eutectic in the second laser remelting scan. This effect led to the formation of globular α-Ni particles with similar Euler's angles in the anomalous eutectic.