Design and characterization of AlNbMoTaCux high entropy alloys laser cladding coatings

AlNbMoTaCu x high entropy alloy coatings was successfully synthesized on Ti6Al4V through laser cladding. The formation, microstructure characterization , micro-hardness, fracture toughness and wear resistance of coatings with different copper addition were investigated. The results show that porosity and crack defects could be suppressed through the addition of copper. The coatings are mainly consists of BCC structure phase enrichment of Mo, Nb, Ta, HCP structure phase enrichment of Al, Nb, Cu, Ti and FCC structure phase with AlCu 2 Ti(Fm-3m). Moreover, as the amount addition of copper increases, BCC structure phase decreases and FCC structure increases, and toughness of the coatings are improved obviously, while the micro-hardness is decreased simultaneously. The wear resistance of AlNbMoTaCu 0 coating is slightly improved 1.6 times than that of the substrate, while the AlNbMoTaCu 0.4 coatings exhibit excellent wear resistance, which is almost 22 times than that of the substrate. Moreover, with the increase of the amount of copper, wear resistance of the coating decreased slightly, and the amount of spalling zone increased in the wear scars. • Copper is vertified to have significant influence on toughness improvement of the AlNbMoTa laser cladding coatings. • Considerably enhanced wear resistance were obtained in copper-added coatings, resulting from the toughness improvement and refined microstructure. • Wear resistance of AlNbMoTaCu 0.4 laser cladding coating is almost 22 times higher than that of Ti6Al4V.