Effect of sintering temperature on phase transformation behavior and hardness of high-pressure high-temperature sintered 10 mol% Mg-PSZ

Abstract The sintering process of zirconia ceramics at high pressures is very different from that under normal pressure. In this paper, 10 mol% MgO partially-stabilized zirconia ceramics (Mg-PSZ) were synthesized under a pressure of 2.5 GPa at temperatures ranging from 1370 to 1610 °C. The effect of sintering temperature on the phase transformation behavior and hardness changes of Mg-PSZ were studied by X-ray diffraction, scanning electron microscopy, Raman spectrometry, and Vickers hardness tests. The optimal sintering conditions of 10 mol% Mg-PSZ were determined. At high pressures, the sintering time was shortened to 60 min, and the sintering temperature was reduced to 1530 °C, which indicates that the high pressure accelerated the sintering rate. Mg-PSZ reached a maximum Vickers hardness of 14.9 GPa at 1530 °C, but when the sintering temperature was further increased to 1610 °C, grain coarsening occurred, and the Vickers hardness decreased to 9.6 GPa.