Preparation and Characterization of Laser Clad AlFeCuCrCoNi High-entropy Alloy (HEA) Coating for Improved Corrosion Performance
J. Menghani, A. Vyas, S. More, C.P. Paul and S. Ingole
The AlFeCuCrCoNi high-entropy alloy (HEA) coating with an approximate thickness of 900 μm was synthesized by the laser-assisted cladding process using a fibre laser on the 316 stainless steel substrate. The microstructure, elemental distribution and phase constituents were characterized. An electrochemical work station was used to evaluate the corrosion behaviour of AlFeCuCrCoNi coating in 3.5 wt.% NaCl solution with the help of potentiodynamic polarization measurement. The microstructural observation reveals that the equiaxed multi principal element coating composed of clad zone (CZ), bond zone (BZ) and heat affected zone (HAZ). Energy dispersive spectroscopy (EDS) indicated that elemental segregation is efficiently reduced, and elements are uniformly distributed in the cladding. X-ray diffraction (XRD) analysis showed the presence of two phases; namely, face-centred cubic (FCC) and body-centred cubic (BCC) phases. The findings suggested that HEA underwent pitting and there was no evidence of uniform corrosion. The study contributes to the understanding of corrosion phenomena.
Keywords: Fibre laser, 316 stainless steel, AlFeCuCrCoNi high-entropy alloy (HEA), corrosion performance, microstructure, corrosion resistance