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Stress‐Biased Anisotropic Microcracking in Zirconia Polycrystals
Author(s) -
ReyesMorel Patricio E.,
Chen IWei
Publication year - 1990
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.1151-2916.1990.tb05152.x
Subject(s) - materials science , anisotropy , tetragonal crystal system , composite material , plasticity , monoclinic crystal system , compression (physics) , elasticity (physics) , phase (matter) , cubic zirconia , condensed matter physics , crystallography , crystal structure , optics , ceramic , chemistry , physics , organic chemistry
Anisotropic elastic response of microcracked bodies has been studied using transformation‐toughened Mg‐PSZ and Ce‐TZP as model materials. These zirconias have been previously deformed in triaxial compression to effect various extents of phase transformation. Microcracks were found to align with the compression axis and their normalized density increases linearly with the extent of transformation plasticity. The measured elastic constants are anisotropic and well described by an elasticity theory. An additional anomalous elastic anisotropy was also found in Ce‐TZP due to a transformation texture of both the remaining tetragonal phase and the newly formed monoclinic phase. The terminal crack density ω= Na 3 , where N is the number of cracks per unit volume and a is the crack radius, reaches 0.05 in Mg‐PSZ and 0.1 in Ce‐TZP at the completion of transformation plasticity.