DURCH MAGNESIUMOXID TEILSTABILISIERTES ZIRKONIUMDIOXID.

摘要

A partially stabilised zirconia body consists of crystalline zirconia contg. 0.05-0.5 wt.% of silica and 2-5-4 wt.% magnesia. It has a structure of cubic zirconia with discrete ppts. of tetragonal and monoclinic zirconia those ppts. havinh an ellipsoidal shape with a long dimension of 0.1-0.4 micron. The body is characterised by specified values of rupture modulus after thermal shock and coefft of thermal expansion according to whether the monoclinic phase is present in the range 10-20 vol.% or 20-60 vol.%. The green body is sintered at 1525-1800 deg.C, cooled at controlled rate to 1300-1450 deg.C; cooled at a controlled rate to 1000-1200 deg.C and optionally aged; cooled to room temp., optionally reheated to 1000-1200 deg.C and aged. Total ageing time is 10-150 hours.