Design and characterization on microstructure evolution and properties of laser-cladding Ni1.5CrFeTi2B0.5Mox high-entropy alloy coatings

Abstract

High entropy alloys (HEAs) is regarded as a newly wear and corrosion resistant material with multi-component structures of equal or near-equal ratio. In this study, Ni1.5CrFeTi2B0.5Mox (x = 0, 0.25, 0.5, 0.75, 1) high-entropy alloys coating were successfully prepared by laser cladding technology to enhance the wear and corrosion resistance of civil commercial engine blades. XRD test was used to study the structural characteristics and determine the crystal structure and their role in HEA samples. The phase structures, microstructure, hardness, wear and corrosion resistance of HEA coatings were specifically investigated. The experimental results indicate that the Ni1.5CrFeTi2B0.5Mox HEAs display good bonding properties between the substrate and the cladding layer. It has revealed that Mo addition will change the coating structure from a single BCC phase to a BCC + FCC dual-phase structure. With the increasing Mo content, the corrosion resistance of Ni1.5CrFeTi2B0.5Mox HEA coating is found enhanced in a certan range in a simulated saturated salty water mud solution and all the coatings exhibit better outstanding corrosion resistance than 904 L stainless steel substrate. It has also found that Ni1.5CrFeTi2B0.5Mox HEA coating can greatly improve the microhardness and wear resistance of the material. The highest average microhardness value (Mo = 1) of HEA coating is 673 HV in the rough, which is about 3.6 times in the comprison with the set substrate. These findings have a clear implication for surface protection that Mo0.75 and Mo1 have a lower volume wear rate and a smoother wear surface, performing better corrosion resistance and wear resistance in comparison with other coatings.