Tensile property and hot corrosion behavior of CrMnFeCoNi high-entropy alloy fabricated via laser melting deposition

Abstract

In the present work, CrMnFeCoNi high-entropy alloy (HEA) was synthesized via laser melting deposition (LMD). The microstructure, microhardness and residual stress of LMD-fabricated specimens were characterized. Additionally, the effect of tensile loading direction on tensile properties as well as hot corrosion behaviors were studied. Results indicated that the columnar grains formed at the top of the LMD-fabricated specimen while mixed columnar and equiaxed grains formed towards the middle and bottom areas. The residual stress parallel to the scanning direction was greater than that in the perpendicular direction, which resulted in a distinction in tensile properties under these two tensile loading directions. The hot corrosion behaviors of LMD-fabricated CrMnFeCoNi HEA in pure NaCl and Na2SO4+NaCl mixed salts were investigated. The chlorine and sulfur ions in molten salts accelerated the degeneration and exfoliation of protective oxide scales, thereby resulting in losing the capacity to resist the hot corrosion.