Effect of Laser Multiple Remelting on the Geometric Parameters and Component Distribution of CrMnFeCoNi High-Entropy Alloys Coatings Fabricated on Al Alloy by Laser Cladding

In this work, CrMnFeCoNi high-entropy alloy coating was successfully prepared on the surface of aluminum alloy by laser cladding. The relationship between the geometrical morphology of the coating cross section and laser process parameters was systematically studied. The influence of line energy and the number of remelting on the morphology of the coating cross section was mainly discussed, and the uniformity of coating elements distribution was regulated by multiple remelting. The coating cross-sectional dimensions, element distribution and hardness values were measured by stereomicroscope, energy-dispersive spectrometer and microhardness tester. The results show that the cladding height of CrMnFeCoNi high-entropy alloy coating increases first and then decreases with the increase of line energy, but the value changes slightly. The cladding width and cladding depth gradually increase with the increase of line energy and remelting times. When the coating is remelted 2 times, there is an incompletely melted island-like CrMnFeCoNi high-entropy alloy powder in the upper left corner of the coating. When remelting 3 times, there is no incompletely melted high-entropy alloy aggregate, and the uniformity of coating is better than that when remelting 2 times. The uniformity of coating composition is the best after 4 remelts, and the hardness of coating reaches 459.67HV_0.2 when the line energy is 0.67 J/mm for 4 remelts.