Compatibility and microstructure evolution of Al-Cr-Fe-Ni high entropy model alloys exposed to oxygen-containing molten lead

Abstract Five Al-Cr-Fe-Ni based high entropy model alloys, mainly a mixture of FCC and BCC or single FCC phase, have been designed and prepared. The corrosion tests of as-cast alloys in oxygen-containing molten Pb show their promising corrosion resistances at 600 °C, which is due to the formation of protective (Fe,Cr)3O4/Al2O3 or Cr2O3/Al2O3 bi-layer. After 2000 h exposure, all alloys are able to maintain the phase compositions obtained from as-cast alloys. However, additional minor phases like σ-phase or precipitation of B2-NiAl either at grain boundaries or adjacent to inter-dendrites are observed.