INFLUENCE OF COMBUSTION ATMOSPHERES ON THE PHASE-TRANSFORMATION OF ZIRCONIA

This letter is concerned with the phase changes and changes in chemical composition in different combustion atmospheres at 700 to 900 degree C of a commercial partially stabilized ZrO//2 material with approximately 12 mol% MgO(Mg-ZrO//2). Observed low-temperature degradation of a commercial tetragonal stabilized ZrO//2 material with approximately 3 mol% Y//2O//3, is also briefly discussed. The main methods of investigation were X-ray diffractometry and secondary-ion mass spectroscopy. Heat treatments in simulated combustion atmospheres of the Mg-ZrO//2 material to 800 to 900 degree C caused material transformation to the monoclinic phase.