| 초록 |
Alumina-reinforced zirconia composites containing 0 to 30 vol% of alumina were fabricated by sintering at 1550˚C for 2h in air. The effect of the Al2O3 content on the mechanical properties and microstructure of 3Y-TZP ceramics was investigated. Al2O3 acted as an inhibitor of the grain growth of 3Y-TZP, and the fracture mode changed gradually from the transgranular mode to the intergranular mode. The Young’s modulus and hardness increased as the alumina content increased. The biaxial flexural strength also showed a slight increase with an increase in the Al2O3 content due to the grain size refinement of the ZrO2 matrix, while the fracture toughness, which was investigated by the SEVNB method, showed a contrary tendency. The decrement of the fracture toughness can be explained by the increase in the critical transformation stress, the decrease in the volume fraction of the transformable t-ZrO2 and the increase in the tensile residual stress. |
