Microstructure and high-temperature wear behavior of CoCrFeNiWx high-entropy alloy coatings fabricated by laser cladding

High-entropy alloys (HEAs) coatings of CoCrFeNiWx (x = 0, 0.25, 0.5, 0.75, 1.0) were fabricated on AISI1045 steel via laser cladding. The microstructure, microhardness and high-temperature performance of the W-doped HEA coatings were investigated. The results show that the W-doped CoCrFeNiWx HEA coatings are composed of a face-centered cubic (FCC) solid solution matrix with unmelted W phases and FCC/intermetallics eutectic structures. The microhardness of the coatings is improved significantly with the increasing W content. The CoCrFeNiW coating exhibits good wear resistance at an elevated temperature of 600 ℃ due to the formation of the oxide layer covering the worn surface. However, the sublimation of WO3 in the oxide film reduces the protective ability to wear at 800 ℃.