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

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 degrees C for 168h. It exhibited remarkably high-temperature strength, yield strength similar to 901 MPa, and true ultimate compressive strength similar to 1186 MPa at 1200 degrees C. The BCC phase and carbide exhibited a semi-coherent interface with good bonding after severe deformation at 1200 degrees C. 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. (C) 2021 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science & Technology.