Methods for preparation of tetragonal zirconia polycrystal composites

摘要

A method for the preparation of tetragonal zirconia polycrystal composite with high toughness and low-temperature degradation resistance. The method comprising adding transformable TZP of ZrO.sub.2 -- Y.sub.2 O. sub.3 --Nb.sub.2 O.sub.5 /Ta.sub.2 O.sub.5 system to non- transformable TZP of ZrO.sub.2 --Y.sub.2 O.sub.3 --Nb.sub.2 O.sub.5 /Ta. sub.2 O.sub.5 system in an amount of not more than 60% by weight based on the total weight of the resulting mixture; and sintering the mixture at above 1,500. degree. C. Even though being exposed to a temperature ranging from 100. degree. to 400° C. for a long time in air, the TZP composite prepared by the present method is rarely transformed into monoclinic zirconia and yet exhibits high toughness.