Recent progress on the microstructure and properties of high entropy alloy coatings prepared by laser processing technology: A review

High-entropy alloy (HEA) has become an attraction for various fields since the advent of 2004. It is an alloy composed of five or more kinds of metallic and non-metallic elements in equimolar or near-equimolar ratios. With unique microstructures, high entropy alloys (HEAs) process many superior properties, such as good wear resistance, corrosion resistance, and superior strength and toughness, excellent thermal stability, oxidation resistance compared with the traditional alloy systems. The common preparation methods of HEAs are magnetron sputtering, laser cladding, electrochemical deposition, among which laser cladding has become a research hotspot in recent years due to its advantages of high energy density, fast solidification rate, small heat-affected zone. In this paper, the research progress of HEA coatings achieved through laser technology in recent years is reviewed, including aspects of the effects of laser processing parameters, the phase composition, microstructure characteristics, and the properties of hardness, strength, plasticity, wear, and corrosion resistance. In addition, the future trends and prospects are outlined.