Phase assemblage and properties of laser cladded TixCrFeCoNiCu high-entropy alloy coating on aluminum

Abstract

The TixCrFeCoNiCu(x:molar ratio, x = 0, 0.2, 0.5, 0.8, 1.0) coating was depositd on aluminum by laser cladding. The phase structure, microstructure, hardness, wear resistance and corrosion resistance were studied. The results show that with the increase of Ti content, the phase structure of the TixCrFeCoNiCu coating changes from single FCC to FCC + B2, and FCC + Laves phase. When Ti is increased to 1.0, cracks appear in the coating. The hardness of the TixCrFeCoNiCu coating is enhanced with the increase of Ti content, and ranges from 215HV0.2 to 585HV0.2, which is about 3 to 7 times that of the substrate. The strengthening mechanism of Ti0.2CrFeCoNiCu is solid solution strengthening, and when the Ti content is greater than 2, the strengthening mechanism of TixCrFeCoNiCu coating is precipitation strengthening. The influence of Ti on the wear resistance exhibits the same trend as with hardness. When Ti increased from 0 to 0.8, the wear rate of the TixCrFeCoNiCu coating changed from 2.26 × 10 -4 mm 3 Nm-1 to 9.92 × 10-7mm3 Nm-1: smaller than the substrate. The addition of Ti increases the current corrosion density of TixCrFeCoNiCu coating, but both coatings still exhibits superior corrosion resistance relative to the substrate.