Microstructural evolution and mechanical properties of ZrO2 (3Y)–Al2O3–SiC(w) ceramics under oscillatory pressure sintering

Abstract ZrO2 (3Y)–Al2O3–SiC(w) ceramics with excellent mechanical properties were fabricated by oscillatory pressure sintering. The influence of sintering temperature on density, microstructural evolution and mechanical properties of such ceramics was studied in this work. The results showed that the selection of proper sintering temperature was favorable for controlling the transformation of t-ZrO2 into m-ZrO2, growth of ZrO2 grains and densification of specimens. The optimal relative density, bending strength, Vickers hardness and fracture toughness of specimens were up to 98.54%, 528 MPa, 13.19 GPa and 7.79 MPa m1/2, respectively. Moreover, the interfacial characteristics at the phase boundary of ZrO2/SiC(w), Al2O3/SiC(w) and ZrO2/Al2O3 were semi-coherent relationship, which was beneficial for increasing the resistance of crack propagation, consequently improving the bending strength and fracture toughness of such ceramics.