Microstructure and properties of age-hardenable AlxCrFe1.5MnNi0.5 alloys

Both alloys display a significant high-temperature age-hardening phenomenon. As-cast Al0.3CrFe1.5MnNi0.5 alloy can attain the highest hardness, Hv 850, at 600 °C for 100 h, and Al0.5CrFe1.5MnNi0.5 can get even higher hardness, Hv 890. The aging hardening is resulted from the formation of ρ phase (Cr5Fe6Mn8-like phase). Prior rolling on the alloys before aging could significantly enhance the age-hardening rate and hardness level due to introduced defects. Al0.5CrFe1.5MnNi0.5 alloy exhibits excellent oxidation resistance up to 800 °C, which is better than Al0.5CrFe1.5MnNi0.5 alloy. Combining this merit with its high softening resistance and wear resistance as compared to commercial alloys Al0.5CrFe1.5MnNi0.5 alloy has the potential for high-temperature structural applications.