METHOD FOR PREVENTING LOW-TEMPERATURE DEGRADATION OF TETRAGONAL ZIRCONIA CONTAINING MATERIALS

摘要

A ceramic body having a surface area containing tetragonal zirconia is sintered to a theoretical density of at least 95% at a temperature of 1550 DEG C or less.;The surface portion is then heat treated to reverse the internal local stress. The low temperature deterioration of the material containing tetragonal zirconia and tetragonal zirconia is greatly improved.;The heat-treated ceramic is particularly suitable for use as a structural component such as a valve, an engine housing, a piston and the like which is exposed at a temperature of 500 DEG C at room temperature for a long time.