Synergistic effects of Al and Ti on the oxidation behaviour and mechanical properties of L12-strengthened FeCoCrNi high-entropy alloys

Synergistic effects of Al and Ti on the oxidation behaviour and mechanical properties of FeCoCrNi high-entropy alloys were systematically investigated. Our results reveal that increasing the Al/Ti ratio slows down the oxidation kinetics at 700-900 ?C and changes the oxide scale from TiO2 and spinel oxides to Cr2O3 and Al2O3, leading to a substantial improvement of oxidation resistance. From a mechanical aspect, however, increasing the Al/Ti ratio decreases the mechanical strength, demonstrating a strong trade-off between oxidation resistance and mechanical properties. The underlying mechanisms for the Al and Ti effects on the oxidation resistance and mechanical properties were discussed.

Automated summary

The synergistic effects of Al and Ti on FeCoCrNi high-entropy alloys were systematically investigated, revealing that increasing the Al/Ti ratio improves oxidation resistance but decreases mechanical strength, demonstrating a trade-off between oxidation resistance and mechanical properties. The underlying mechanisms for these effects were discussed.