ZrO2 sintered compact and method for its production.

摘要

Conventionally, a ZrO(sub 2) sintered compact that has been made by adding a small amount of Y(sub 2)O(sub 3) to ZrO(sub 2) is generally sub-stable tetragonal and is tough at low temperatures because of stress-induced transformation from the tetragonal to the monoclinic phase. Thus such compacts have been used primarily for tools that are used at low temperatures, such as cutlery. The addition of HfO(sub 2) is effective for raising the temperature at which the tetragonal crystal of a ZrO(sub 2) sintered compact is stabilized and thus for improving its toughness at higher temperatures: i.e., for keeping the tetragonal crystal in a sub-stable state even at high temperatures. However, when HfO(sub 2) was substituted for ZrO(sub 2) in a ZrO(sub 2) sintered compact containing Y(sub 2)O(sub 3), it was not possible to obtain an adequate toughness at high temperatures. With reference to the above discussion, the purpose of this invention is to provide a ZrO(sub 2) sintered compact and a method for its production whereby the ZrO(sub 2) sintered compact is made superior in toughness at high temperatures by selecting the most appropriate stabilizer.