| Popis: |
The microstructure and mechanical properties of pressureless sintered and subsequently hot isostatic pressed Y-TZP ceramics containing up to 20 vol% of SiC particles were studied. The grain growth of the ZrO 2 matrix was not significantly affected by SiC additions. It was found that the hardness, Young's modulus and fracture toughness K IC increased, and the bending strength, σ b , decreased with increasing SiC content. The maximum K IC and σ b were 7·8 MPa√m and 849 MPa, respectively. Silicon carbide additions caused increased flaw sizes, and reduced thermal stability of tetragonal zirconia during low-temperature ageing. The dominant toughening mechanism was microcracking. Stress-induced phase transformation played only a secondary role. |
