Synergistic enhancement of strength and plasticity in CoCrFeNiMn high-entropy alloys by novel core-shell microstructure design

The novel core-shell SiC@CoCrFeNiMn high-entropy alloy (HEA) matrix composites (SiC@HEA) were successfully prepared via mechanical ball milling and vacuum hot-pressing sintering (VHPS). After sintering, the microstructure was composed of FCC solid solution, Cr$_{23}$C$_6$ carbide phases, and Mn$_2$SiO$_4$ oxy-silicon phase. The relative density, hardness, tensile strength, and elongation of SiC@HEA composites with 1.0 wt.% SiC were 98.5%, HV 358.0, 712.3 MPa, and 36.2%, respectively. The core-shell structure had a significant deflecting effect on the cracks. This effect allowed the composites to effectively maintain the excellent plasticity of the matrix. As a result, the core-shell SiC@HEA composites obtained superior strength and plasticity with multiple mechanisms.