Microstructure and tribological property of selective laser melted Ni-based composites using different scanning strategies

The effect of laser scanning strategy on microstructure and tribological property of WC/Inconel 718 composites manufactured by selective laser melting (SLM) was investigated. The microstructure of composites demonstrated columnar dendrites with <001> texture while the precipitates distribution and dendrites spacing were distinct by virtue of heat flux rotation. The island strategy with nearly full density possessed high microhardness (366.2 HV0.2) and low wear rate (1.72 x 10(-4) mm(3)/N.m), showing the superior wear resistance. The wear rate of cross-direction displayed little difference with island owing to their similar structures. While the remelting strategy demonstrated spherical pores and aggregated precipitates owing to the excessive heat-input, which was more easily subjected to wear and mechanism transformed from abrasive wear to severe plastic deformation and adhesion. Besides, the wear resistance was weakened and wear debris transformed to flakes with the increase of applied load because of the effect of surface damage and loss.