Research on Toughening Mechanics of Zirconia Toughened Alumina Composite Ceramics

Toughening mechanics of ZrO2 toughened Al2O3 composite ceramics was researched by mechanical property test and X-ray phase analysis. The results show that: t→m phase transformation rate of ZrO2 is one of the main factors in zirconia toughened alumina composite ceramics. If samples are broken down, t→m phase transformation rate of ZrO2 is the highest when ZrO2 content is 25%. At the same time the rate of nano-zirconia toughened alumina ceramics is higher than that of sub-micron composite ceramics. So fracture toughness of ceramics can be improved significantly by adding proper amount of ZrO2 into Al2O3 matrix and refining ZrO2 particles. In addition, to nano-zirconia particles, some other toughening mechanics exist such as nano effects, microcrack toughening, etc.