High-temperature ultra-strength of dual-phase Re0.5MoNbW(TaC)0.5 high-entropy alloy matrix composite

Abstract

Abstract The dual-phase Re0.5MoNbW(TaC)0.5 composite, consisting of refractory body-centered cubic (BCC) high-entropy alloy and carbide with many fine eutectic structures, was successfully synthesized by arc melting. The phase stability, high-temperature mechanical properties and strengthening mechanism of the as-cast composite were studied. The microstructure of the composite remained stable after annealing at 1300℃ for 168h. It exhibited remarkably high-temperature strength, yield strength ∼ 901 MPa, and true ultimate compressive strength ∼ 1186 MPa at 1200℃. The BCC phase and carbide exhibited a semi-coherent interface with good bonding after severe deformation at 1200℃. The dipolar dislocation walls in BCC phase, restricted dynamic interaction between defects in carbide, and the pinning effect of semi-coherent interface offered effective strengthening effects.