Abstract
Eutectic high-entropy alloys (HEAs) have displayed excellent mechanical performance, thermal stability and great potential for industrial-relevant applications. Herein, the thermal stability of a newly designed lightweight Al21Ti21V16Ni21Co21 eutectic HEA was assessed by thermal exposure at a temperature of 1,373 K for 10 h. A relatively bulk 10 kg ingot was prepared by vacuum induction melting. The alloy in as-cast state with a density of 6.19 g/cm3 exhibited an anomalous eutectic dual-phase structure, consisting of Ni2AlTi-type L21 and V-rich body-centred cubic phases. It achieved a compressive yield stress of ~1,417 MPa and an ultimate compressive stress of ~2,312 MPa. Remarkably, after thermal exposure, the alloy basically retained its initial microstructure and nearly 100% of its mechanical properties. Comparative analysis of its mechanical performance and retention capability with those of other eutectic HEAs, refractory HEAs, and conventional superalloys revealed that the Al21Ti21V16Ni21Co21 alloy offers a significantly broader application temperature range.