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Microcracking in Ceramics Induced by Thermal Expansion or Elastic Anisotropy
Author(s) -
TVERGAARD VIGGO,
HUTCHINSON JOHN W.
Publication year - 1988
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.1151-2916.1988.tb05022.x
Subject(s) - materials science , anisotropy , grain boundary , thermal expansion , crystallite , ceramic , planar , grain size , composite material , triple junction , stress (linguistics) , hexagonal crystal system , condensed matter physics , mineralogy , crystallography , metallurgy , microstructure , geology , optics , chemistry , physics , linguistics , computer graphics (images) , optoelectronics , philosophy , computer science
The effect of crystal anisotropy on the formation of grain‐boundary microcracks is analyzed, by considering a planar array of hexagonal grains as a model of a polycrystalline ceramic. The stress singularities at triple‐grain junctions are analyzed by an asymptotic method as well as by a numerical solution, and the critical size of a grain‐boundary defect is investigated by a crack analysis. It is found that elastic anisot‐ropies can significantly increase the stress levels near triple points, which results in a smaller critical grain size for microcracking.