Research on Microstructure and Wear Resistance of AlCuFeMnNi High-entropy Alloy

In order to study the phase structure, microstructure, microhardness and wear resistance, AlCuFeMnNi high-entropy alloy prepared by vacuum melting was investigated by X-ray diffractometer, optical microscope, microhardness tester and friction-wear tester. The results show that AlCuFeMnNi alloy is a dual-phase structure composed of BCC main phase and FCC phase. The microstructure of AlCuFeMnNi alloy is composed of BCC dendrite region and FCC interdendrite region, which belongs to typical dendritic structure. The small dendrite structure in the bottom area of the ingot is due to the small interface thermal resistance, fast heat dissipation, large temperature difference and undercooling degree and high nucleation rate. There is no large region of interdendrite region in the top area, which is due to the "small molten pools" separated by the "branches" of coarse dendrites during the solidification. The microhardness, friction coefficient and mass loss rate of AlCuFeMnNi high-entropy alloy are 423.5 HV0.5, 0.61 and 0.40%, respectively. The friction-wear curve of AlCuFeMnNi alloy shows a rapid rise first and then a stable trend with the increase of time, which is mainly due to the rapid increase of friction coefficient with the increase of resistance and contact area at the initial stage of friction and the change of wear mechanism from the initial delamination wear to the later oxidation wear.