Microstructure and corrosion properties of Al2CrFeCoxCuNiTi high entropy alloys prepared by additive manufacturing

Abstract The Al2CrFeCoxCuNiTi high-entropy alloy coatings were prepared by additive manufacturing. The microstructure and corrosion resistance were researched. The results show that the microstructure of Al2CrFeCoxCuNiTi high entropy alloy coating is mainly composed of equiaxed grains and columnar grains, with fine spherical particles distributed on the equiaxed grains. The coating is easy to crack under the action of thermal stress. The internal stress can be reduced and the crack can be eliminated by adding 2% Si and additive manufacturing process. The corrosion resistance of the coating with 2% Si addition in 0.5 mol/L HNO3 solution is excellent, compared with Q235 steel, the self corrosion current density of the coating is reduced by 1–2 orders of magnitude, and the self corrosion potential shifted to the positive direction by 0.02–0.30 V. The corrosion resistance of the coating decreases with the increase of Co content.