Effects of Nb addition on the laser energy efficiency and properties of (NiCrCoFe) 100-x Nb x HEA underwater wet laser cladding coatings

Underwater wet laser cladding technology (UWLC) offers advantages such as short repair cycles, low costs, and independence from drainage equipment, making it highly practical. The exceptional design flexibility of high entropy alloys, combined with the convenience of UWLC technology, presents significant application potential. To assess the feasibility of utilizing high entropy alloys (HEAs) in underwater wet laser cladding, (NiCrCoFe) 100-x Nb x (x = 0, 5, 10) coatings were prepared. This study investigates the effects of Nb addition on the formation characteristics and metallurgical process of (NiCrCoFe) 100-x Nb x HEA coatings. The results show that the addition of Nb promotes the efficient utilization of laser energy underwater by altering the melting latent heat of UWLC materials and enhancing the fluidity of the molten pool. Furthermore, the introduction of Nb element improves the corrosion resistance of the coatings and inhibits the expansion of corrosion pits. This study confirms the feasibility of utilizing high entropy alloys for underwater wet laser cladding and offers new ideas and methods for the underwater online repair of marine equipment.