Achieving ultrahigh aluminum melt corrosion resistance via laser-induced nanoeutectic architectures in WMoTaNb high-entropy alloy coatings

Aluminum melt corrosion severely damages iron-based components in manufacturing, necessitating advanced corrosion-resistant materials. This study investigates laser-clad WMoTaNb high-entropy alloy (HEA) coatings on H13 steel to address this challenge. By varying laser scanning speeds (600–1200 mm/min), microstructural evolution and corrosion resistance were systematically analyzed. At 1200 mm/min, the coating possesses a nano-eutectic structure comprising high-entropy BCC and α-Fe phases, which can reduce the corrosion depth by 92.8 % compared with H13 steel after 4 h in 1013 K molten Al. Advanced characterization reveals that Al atoms preferentially react with α-Fe, while the high-entropy BCC phase can suppress Al diffusion through sluggish diffusion effects and the formation of a nanoscale amorphous transition layer. First-principles calculations confirm that disordered atomic arrangements in the BCC phase significantly elevate Al diffusion barriers compared to α-Fe. Furthermore, the nano-eutectic structure not only restricts the preferential growth of FeAl 3 , but also mitigates thermal stress mismatches, preventing IMC layer exfoliation. This work demonstrates that laser-induced nano-eutectic architecture has remarkable corrosion resistance and interfacial stability, providing a novel strategy for designing HEA coatings against extreme liquid metal corrosion.