Effect of pre-oxidation on increasing resistance of Fe–Al–Ni–Cr–Co–Mn high entropy alloys to molten Al attack

Abstract

The corrosion behaviours of two high entropy alloys (HEAs, namely Fe–Al–Ni–Cr–Co and Fe–Al–Ni–Cr–Co–Mn) in molten Al, each with and without pre-oxidation treatment, were investigated. Both bare alloys lost their thickness owing to dissolution, and various intermetallic compounds formed on their substrate surfaces during immersion in molten Al. Pre-oxidation treatment gave rise to the formation of an effective oxide barrier on each alloy surface against molten Al attack. The characteristics of pre-formed oxides in resisting molten Al attack were examined using electron backscatter diffraction (EBSD) analysis.