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Structure and Thermomechanical Properties of Partially Stabilized Zirconia in the CaO‐ZrO 2 System
Author(s) -
GARVIE RONALD C.,
NICHOLSON PATRICK S.
Publication year - 1972
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/j.1151-2916.1972.tb11241.x
Subject(s) - materials science , substructure , cubic zirconia , microstructure , thermal shock , monoclinic crystal system , composite material , phase (matter) , thermal expansion , ceramic , thermal , mineralogy , scanning electron microscope , crystallography , crystal structure , thermodynamics , geology , chemistry , structural engineering , physics , organic chemistry , engineering
Partially stabilized zirconia (PSZ) ceramics in the system CaO‐ZrO 2 were characterized. The microstructure, as revealed by optical microscopy, consisted of grains of pure ZrO 2 distributed in a matrix of fully stabilized material. Electron microscopy showed that the matrix grains have a complex substructure of 1000‐Å domains of cubic and monoclinic ZrO 2 . The grains appeared to fit Ubbelohde's concept of a hybrid single crystal. Evidence obtained indicated that the substructure provides an effective stress‐relieving mechanism during thermal shock. It is proposed that initiation of phase inversion in pure ZrO 2 domains, even at subtransition temperatures (by thermal stresses), creates an extremely large microcrack density. On the basis of Hasselman's thermal‐shock criterion, only quasi‐static crack propagation occurs during thermal shock of PSZ; evidence is presented to support this concept.