Effects of Temperature and Chemical Composition of Intergranular Glass on Dihedral Angle of Glass-Doped 3Y-TZP

Abstract

Fig. 1. Dihedral angle ( q ) in multiple pocket of glasscontaining ceramic (YASdoped 3YTZP). g SS is the grain boundary energy, and g SL is the interface energy between grain and glass. The distribution and the morphology of glass phase in polycrystals are affected by the dihedral angle and the volume fraction of the glass phase. The effects of temperature and chemical composition of intergranular glass on dihedral angle of glassdoped 3mol÷yttriastabilized tetragonal zirconia polycrystals (3YTZP) were studied by transmission electron microscopy (TEM). The intergranular glass was either SiO 2 (melting point of 1700 C) or Y 2 O 3 Al 2 O 3 SiO 2 eutectic glass (YAS glass: melting point of 1350 C). The average dihedral angles of SiO 2 doped and YASdoped 3YTZP, which were sintered at 1300 C, were found to be 70 and 50 , respectively. The dihedral angle in YASdoped 3YTZP decreased to 25after annealing at 1500 C, whereas that in SiO 2 doped 3YTZP remained constant. From the relationship between the dihedral angle and the ratio of grain boundary energy to solid/glass interface energy (g SS /g SL ), it was suggested that g SS /g SL increased at elevated temperatures higher than the melting point of glass.