Sintering oxide ceramics based on AI₂O₃ and ZrO₂, activated by MgO, TiO₂ and SiO₂ additives

The positive effect of the addition of MgO and TiO₂ in an amount of no more than 1 wt. % on sintering and physico-mechanical properties of alumina ceramics is established. Addition of 5% of SiO₂ to A1₂O₃ provides the mechanism of liquid phase sintering of ceramics, which leads to increase in its density and strength up to 480 MPa. In ceramic system A1₂O₃ - ZrO₂ - Y₂O₃ highest level of physical and mechanical properties of the composition had a hypereutectic composition 16.6% A1₂O₃ - 76% Z1O₂ - 7.4% Y₂O₃. In this composition two mechanisms of hardening are realized simultaneously, such as transformational hardening by t- m - ZrO₂ transition and dispersion strengthening with high-modulus particles of α- A1₂O₃.