Effect of B4C particles addition on microstructure and mechanical properties of Fe50Mn30Co10Cr10 high-entropy alloy

High entropy alloy used as the metallic matrix of composites gives birth to a new family of composites. In this work, the effect of B4C particles on microstructure and mechanical properties of Fe50Mn30Co10Cr10 high-entropy alloy matrix is systematically investigated. B4C particles can stabilize austenite (gamma) phase to form single gamma phase and effectively refine grain size. Two different sizes and compositions of B4C particles are formed in B4C/Fe50Mn30Co10Cr10 composite. The fine B4C particles with the lower Cr contents can induce significant coherent strain and then strengthen the matrix, while the coarse B4C particles with the higher Cr content can induce micro-crack at the B4C/matrix interface due to the low interfacial metallurgical bonding. As compared to Fe50Mn30Co10Cr10 matrix, B4C/Fe50Mn30Co10Cr10 composite shows the higher tensile strength with the relative lower fracture strain. In addition, the composite possesses a better ability of wear friction than the matrix, revealing the oxidative wear and abrasive wear mechanism.