Microstructure and corrosion properties of laser remelted CrFeCoNi and CrMnFeCoNi high entropy alloys coatings

Abstract

CrFeCoNi and CrMnFeCoNi coatings were prepared using laser remelting technology. The microstructure and phase composition of coatings were investigated. X-ray diffraction (XRD) results indicated that CrFeCoNi and CrMnFeCoNi coatings presented face-centered cubic structure. Electrochemical measurements were used to reveal the corrosion behavior of coatings. Results showed that CrFeCoNi coating exhibited lower corrosion current density, lower passive current density and higher charge transfer resistance than CrMnFeCoNi coating in H2SO4 solution (0.5 mol/L). This indicated that CrFeCoNi coating possessed higher corrosion resistance. Mott–Schottky analysis revealed that the passive film formed in CrFeCoNi coating possessed lower donor density value in contrast with that of CrMnFeCoNi coating, suggesting that CrFeCoNi coating formed a more protective passive film. The corrosion mechanisms of coatings were also revealed.

Keywords

• CrFeCoNi and CrMnFeCoNi
• Laser remelting
• Corrosion
• XPS
• Passivity