Preparation of near iso-atomic ratio aluminium-based high-entropy alloyed high-performance coatings by laser multiple remelting process

The laser remelting process eliminates coating cracks and improves elemental distribution uniformity. Laser clad high-entropy alloy coatings are expected to achieve homogeneous, high-performance aluminum alloy coatings via multiple remelting laser processes. In this work, the combination of laser cladding and multiple remelting processes further optimizes the aluminum alloy coating process and achieves the preparation of high-performance CrMnFeCoNi high-entropy alloy coatings. The 100 μm scanning interval of the coating corresponds to the optimal surface flatness, and the average hardness of the coatings is above 215 HV_0.2, which is 1.6 times greater than that of the aluminum alloy substrate. Increasing the number of remelts to four resulted in a more homogeneous distribution of elements in the high-entropy alloy and improved corrosion resistance. The corrosion resistance increases and then decreases with increasing scanning interval. Among the four remelts, the best corrosion resistance was achieved at a scanning interval of 200 µm, with a 50 % improvement over the substrate. The volume wear of the coating is one order of magnitude lower than that of the substrate.