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 AlCu2Ti(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 AlNbMoTaCu0 coating is slightly improved 1.6 times than that of the substrate, while the AlNbMoTaCu0.4 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.

Automated summary

AlNbMoTaCu(x) high entropy alloy coatings were successfully synthesized on Ti6Al4V through laser cladding. The addition of copper effectively suppressed porosity and crack defects. The increase in copper content resulted in improved toughness and reduced micro-hardness of the coatings. The wear resistance of AlNbMoTaCu coatings was significantly enhanced, with the AlNbMoTaCu0.4 coatings exhibiting excellent wear resistance.