Solidification and tribological behavior of CoCrFeMnNi high entropy alloy fabricated by laser powder bed melting

High entropy alloys are suitable for manufacturing large-sized or intricately shaped components used in harsh environments, but their processing is hindered by high melting point, high viscosity, and poor melt flowability. Laser powder bed melting (L-PBF) is an effective method for manufacturing the above-mentioned components, but the unique layer-by-layer deposition and rapid solidification will create high anisotropy and fine substructures, yet their impact on wear resistance and friction layer formation is limited. This study primarily investigated the influence of various laser powers (120 W, 140 W, 160 W, 180 W) on the solidification microstructure, mechanical properties, and wear resistance of CoCrFeMnNi alloy. The results showed that as the laser power increased from 120 W to 180 W, the cell diameter expanded from 0.368 mu m to 0.612 mu m, and the crystallographic texture transitioned from < 111 > to < 100 > and < 110 > orientations. This transition leads to a steady decrease in yielding strength until it achieves the optimal mechanical properties at 140 W. Tribological tests against Si3N4 balls demonstrated a typical inverse correlation between wear rate and hardness. Analysis of the worn surface's morphology and chemical composition of the worn surface showed that increasing the cell diameter will not alter the primary wear mechanism, but does lead to increased oxidative and adhesive wear.