Zirconia (ZrO2) has shown great projection among the advanced ceramics, attracting the interest of researchers in its various fields of application. Tetragonal zirconia presents high mechanical strength, but the room temperature stable phase is the monoclinic, being necessary the use of stabilizers for obtaining the tetragonal phase. In this work the rapid sintering of zirconia partially stabilized with rare earth oxides (ZrO2-OTR), via 5 GPa high pressure is proposed. The sintering conditions employed in this work are innovative, due to the use of an alternative technology to process ZrO2-OTR, so called high temperature - high pressure (HPHT). A pressure of 5 GPa and temperatures of 1100, 1200 and 1300 ºC for times of 2 and 5 min were used. The best results were obtained for samples sintered at 5 GPa at 1300 ºC/5 min., where a micro-hardness of 488,73 kgf/mm², a fracture toughness of 5,33 MPa.m½, a density of 97,88%, and a 88vol.% of tetragonal phase retained at room temperature were achieved.
ZrO2; rare earth oxides; sintering; high pressures; tetragonal phase
