Corrosion behavior of Al2CrFeCoxCuNiTi high-entropy alloy coating in alkaline solution and salt solution

Abstract

Abstract The Al2CrFeCoxCuNiTi high-entropy alloy coatings were prepared by laser cladding. The microstructure of the coatings was tested by micro analysis instrument. Electrochemical properties of coating and matrix were tested by electrochemical analysis instrument. The results show that the cladding zone is mainly composed of equiaxed grains, as well as fine particles and white “fishbone” grains distributed in the matrix grains. The corrosion resistance of Al2CrFeCoxCuNiTi coatings is excellent in 1\u202fmol/L NaOH and 3.5\u202fwt% NaCl solutions. The corrosion current density of Al2CrFeCoxCuNiTi high-entropy alloy coating in 1\u202fmol/L NaOH solution is reduced by 3 orders of magnitude compared with Q235 steel, and the corrosion potential is positively shifted to 0.03–0.27\u202fV. The corrosion current density of Al2CrFeCoxCuNiTi high-entropy alloy coating in 3.5\u202fwt% NaCl solution is lower than that of Q235 steel. The corrosion potential moves toward “positive” except for Co0.0 coating, and the movement amplitude is 0.06–0.35\u202fV. Cyclic polarization curve shows no pitting corrosion in the 3.5\u202fwt% NaCl solution for the Co1.5 high-entropy alloy coating, but slight pitting corrosion in 1\u202fmol/L NaOH solution for the Co1.5 high-entropy alloy coating.