Designing high entropy alloy-ceramic eutectic composites of MoNbRe0.5TaW(TiC)x with high compressive strength.

Combining the advantages of composites and eutectic high entropy alloys, novel MoNbRe 0.5 TaW(TiC) x high entropy alloy-ceramic eutectic composites with high strength were successfully designed and investigated based on the computer assisted thermodynamic calculation. The MoNbRe 0.5 TaW(TiC) x composites are composed of body-centered cubic (BCC) solid solution and multi-component (MC) carbide with face-centered cubic (FCC) structure. With increasing TiC addition, microstructure exhibits an evolution from hypo-eutectic to eutectic and then to hyper-eutectic, which is explained by the solidification process analysis in calculated equilibrium phase diagram. The MoNbRe 0.5 TaW(TiC) x composites possess high strength. The MoNbRe 0.5 TaW(TiC) 1.0 fully eutectic composite has the highest compressive strength of 1943 ± 13 MPa with high yield strength of 1496 ± 17 MPa. The strengthening mechanism is contributed by the synthetic effect of second-phase and boundary strengthening. Image 1 • HEA-ceramic eutectic composites of MoNbRe 0.5 TaW(TiC) x are designed and prepared. • The calculated results agree reasonably well with the experimental results. • Eutectic structure consists of BCC phase and MC carbide with good phase interface. • Eutectic composite exhibits excellent strength. • Strengthening mechanism is combination of second-phase and boundary strengthening. [ABSTRACT FROM AUTHOR]