| 摘要 |
1519314 Partially stabilized zirconia COMMONWEALTH SCIENTIFIC & INDUSTRIAL RESEARCH ORGANISATION 22 Oct 1975 [24 Oct 1974] 43389/75 Heading C1A A partially stabilized zirconia (PSZ) ceramic body contains between 3À3 and 4.7% by weight of calcia and has a fine-scale two phase microstructure consisting of metastable tetragonal domains of a critical size within cubic matrix grains, which domains, in regions of high stress, irreversibly transform to normal monoclinic form upon stressing of the body. The PSZ may be made by firing material containing zirconia and calcia so that the final composition comprises between 3À3 and 4À7 weight per cent of calcia at a temperature between 1700-1950‹C and allowing the body to cool at an average rate of at least 175‹C hr', until the temperature is 1200-1450‹C, ageing at 1200-1450‹ for a time such that peak strength is obtained. The cooling and ageing may be carried out separately by cooling to room temperature and then reheating to ageing temperature. The material may be moulded before firing. |
