Microstructure and properties of MgMoNbFeTi2Yx high entropy alloy coatings by laser cladding

High-entropy alloys (HEAs) are promising as a new type of engineering material with extensive research value. Rare-earth elements are widely studied and used to prepare HEAs because of their unique properties. In this work, the MgMoNbFeTi2Yx (x = 0, 0.4%, 0.8% 1.2%) HEA coatings were manufactured by laser cladding technology. The effect of Y on the phase structure, microstructure, wear resistance, microhardness and corrosion resistance of the laser cladding coatings were investigated methodically. As a result, the coating samples exhibit brilliant bonding abilities between substrates and claddings layer with Y additives. When Y content is low, the phase composition consists of a face centered cubic (FCC; Mg, Ti-rich (Nb, Ti) C carbide) and biphasic body centered cubic (BCC) solid solution. With an increment in Y content (Y = 0.8%/1.2%), the phase composition is composed by one BCC phase along with FCC. In the simulated saturated saline cement solution, corrosion resistance of the HEA coating is enhanced by Y addition. In addition, the MgMoNbFeTi2Y0.8% HEA coating show an excellent corrosion resistance. The MgMoNbFeTi2Y1.2% HEA coating displays the highest average microhardness of about 1046 HV0.3, which is 2.7 times stronger than that of the coating without Y content (Y = 0) and more than 5 times higher than that of the average microhardness of the base material. More interesting, such HEA coating shows an excellent wear resistance. This work can provide a novel and effective approach to significantly improve the surface quality of the characteristics of HEAs, which will promote them further applications as a promising candidate material in advanced manufacturing fields.