Effect of SiO2 on mechanical properties of a ZnS-SiO2 composite prepared by spark plasma sintering

Abstract

Raw ZnS and ZnS-SiO2 powder prepared by a 3-D mixer or high energy ball-milling were successfully densified by spark plasma sintering. The mechanical properties were evaluated by microhardness and fracture toughness and correlated to the microstructure. In case of the ball-milled ZnS-SiO2 powder, mechanical properties were the highest as a result of a finer and more homogeneous microstructure. Due to the effect of dispersion hardening and crack deflection by the second phase of fine SiO2, the hardness and fracture toughness reached 3.031 GPa and 1.014 MPa·m0.5, respectively.