Microstructural evolution of Al 0.25 CoCrFeNiCu and Al 0.45 CoCrFeNiSi 0.45 high-entropy alloys during laser cladding

Abstract

Additive manufacturing of high-entropy alloys has recently attracted considerable scientific interest owing to their exceptional mechanical properties and corrosion resistance. In this work, Al_0.25CoCrFeNiCu and Al_0.45CoCrFeNiSi_0.45 high-entropy alloys coatings are deposited on stainless steel using laser cladding. The prealloyed high-entropy alloys fabricated by arc melting followed by crushing were used as a precursor for laser cladding, which significantly decreased the optimum laser power to 1400–1600 W and hence minimized the thermal effect on the substrate. Laser cladding preserved the dendritic structure of arc melted alloys, while highly refined the dendritic microstructure. Some extent of substrate dilution effect was also observed in the cladding layers.