Deposition of High-Entropy Alloy Coating by Cold Spray Combined with Laser Melting: Feasibility Tests

In this work, the new two-stage approach of deposition of high-entropy alloy coatings on aluminum substrate is considered. At the first stage, the 2.5 mm thick composite precursor coating was deposited on aluminum substrate by cold spray using two mixtures of five metal powders (Cu + Al + 316L + Tribaloy 700 and Al + Ti + 316L + Tribaloy 700). At the second stage, the laser melting of 500-1000 µm layer at the top surface of the composite coatings was performed. The microstructure analysis revealed good element mixing in the melting pool during laser melting. EDS and phase analysis showed that in case of Cu + Al + 316L + Tribaloy 700 mixture, the laser melting allowed formation of Al0.1CuCr0.4FeNi0.4Mo0.2Si0.1 coating with fcc structure. In case of Al+Ti+316L+T700, the synthesis of Al0.1Cr0.4FeNi0.8Mo0.2Si0.05Ti coating with complex structure including different phases was observed after laser melting. Performed feasibility study showed that developed hybrid approach could be applied for elaboration of other high-entropy alloy coatings.