Carbide-reinforced Re0.1Hf0.25NbTaW0.4 refractory high-entropy alloy with excellent room and elevated temperature mechanical properties

Abstract

Refractory high-entropy alloy (RHEA) with high elevated-temperature strength is generally brittle at room-temperature, which greatly restricts the workability and application of the RHEA. Here, we report a novel Re0.1Hf0.25NbTaW0.4C0.25 RHEA with both excellent high-temperature strength and decent room-temperature ductility. Meanwhile, the microstructure and mechanical properties of Re0.1Hf0.25NbTaW0.4C0.25 RHEA were investigated. The microstructure of the alloy was composed of BCC matrix phase and eutectic phases (BCC+(MC + M2C)), and lots of secondary carbides were dispersedly precipitated in the BCC matrix. Due to the synergistic strengthening effect between the BCC matrix and the carbides. The alloy exhibited excellent compressive strength of 1026 MPa at 1450 °C and 523 MPa at 1700 °C, with a good compressive fracture strain of 10.2% at room-temperature. The Re0.1Hf0.25NbTaW0.4C0.25 RHEA has potential applications in the field of ultra-high-temperature structural materials.