Influence of laser power on microstructure evolution and properties of laser cladded FeNiCoCrMo HEA coatings

Abstract

The present study is to investigate the effect of laser on the microstructure evolution, wear and corrosion resistance of FeNiCoCrMo high entropy alloy (HEA) coatings, which were prepared on 304 stainless steel by laser cladding technology. The results showed that the HEA coatings were mainly composed of face-centered cubic (FCC) solid solution structure (Ni-Cr-Co-Mo) and rhombohedral structure (Fe3Mo and CoMo2Ni). The laser power will directly affect the content and distribution of each phase. With the increase of laser power, the content of Ni-Cr-Co-Mo phase decreases, the contents of Fe3Mo phase and CoMo2Ni phase increase obviously, and the Mo phase gradually decreases to disappear. When the laser power is 1200 W, there is a relatively clear boundary between the eutectic structure and the strengthening phase in the microstructure, but when the laser power is 1800 W, the eutectic structure and the strengthening phase have infiltrated each other, and the phases are in a chaotic state. The wear resistance of HEA is better at low laser power, and the corrosion resistance of HEA is better at high laser power. The wear and corrosion mechanisms for different samples were discussed. This work is helpful to understand the existing state of Mo element in FeNiCoCrMo coating and the influence of phase composition and distribution on the wear resistance and corrosion resistance of the coating.