Wetting and interfacial behavior of Fe, Co, Ni on (Ti, Zr, Hf, Nb, Ta)C high entropy ceramics

Abstract

The wetting of (Ti, Zr, Hf, Nb, Ta)C) high entropy carbide ceramics by molten metals was studied using a sessile drop method in a vacuum environment. Fe, Co, and Ni demonstrate good wetting with the (Ti, Zr, Hf, Nb, Ta)C substrate forming a final contact angle of 20°, 30°, and 22°, respectively. A detailed characterization of solidified couples was performed by scanning electronic microscopy to study the microstructure of the drop and interaction region. Dissolution of the (Ti, Zr, Hf, Nb, Ta)C ceramics components into metal accompanied with metal penetration into the ceramic's substrate was found to occur during high-temperature tests. Formation of (Nb,Ta)C– ZrC-, HfC-based solid solutions and Me5(Ti,Zr,Hf) intermetallics takes place in the (Ti, Zr, Hf, Nb, Ta)C–Me systems due to dissolution-recrystallization phenomena.