Effects of milling time and sintering temperature on the mechanical properties of 8 wt% WC/AlCoCrFeNiTi0.5 high entropy alloy matrix composite

Abstract

The present study investigates the effect of milling time, and sintering temperature on the microstructure and mechanical properties of the spark plasma sintered 8 wt% WC/AlCoCrFeNiTi0.5 high entropy alloys matrix composite (HEAC). The results show that the grain size is decreased first and then increased with an increase of milling time. The refined grain along with the homogeneous distribution of reinforcements is observed when milling for 15 h. It also shows both of relative density and compression strength of compacts are increased first and then decreased with an increase of sintering temperature. A highest relative density of 99.89 % and a fracture strength of 2683 MPa are obtained at 1150 °C. Another, sintering leads to crystal structure transition from BCC to FCC for the solid solution phase. The formation of (Fe, Co)6W6C complex carbide as a main strengthening phase is conducive to the enhancement of hardness. The strengthening mechanism is mainly attributed to dislocation strengthening and Orowan mechanism.