THERMOMECHANICAL AND MICROSTRUCTURAL EVALUATION OF HIGH-TEMPERATURE SINTERED (MG,MG-TI)-PSZ

The sintering of (Mg, Mg-Ti)-PSZ up to 1700 degrees C and the attendan t changes in the thermal shock resistance after quenching from various temperatures have been studied. The effect has also been quantified i n terms of retained bend strength after thermal cycling from four diff erent temperatures in the range of 400 degrees C and 1000 degrees C to room temperature. Thermal cycling of the specimens which are sintered at 1500 degrees C and aged at 1150 degrees C leads to growth of Ti-ri ch whisker and coral-like features isostructural with cubic-ZrO2, and these are the main contribution to the improved thermal shock resistan ce. Sintering at higher temperatures and thermal cycling result in mar kedly different precipitate morphologies because of the presence of Ti O2.