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Strength and Its Variability in Ceramics with Particular Reference to Alumina
Author(s) -
RITTER J. E.,
DAVIDGE R. W.
Publication year - 1984
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.1151-2916.1984.tb19731.x
Subject(s) - materials science , ceramic , microstructure , fabrication , crystallite , composite material , stress (linguistics) , grain boundary , fracture (geology) , forensic engineering , metallurgy , medicine , linguistics , philosophy , alternative medicine , pathology , engineering
Research was conducted to measure the strength and its variability in polycrystalline alumina with a wide variety of high‐density arrays of flaws. The flaw arrays were produced by grit‐blasting the surface, processing samples with small (10 μm diameter) and large (100 μm diameter) closed pores, underfiring samples to give interconnected grain‐boundary pores, and fabricating microcracked Al 2 O 3 ‐ZrO 2 composites. Although details of the failure process can be complicated, strength was controlled in all cases by either the stress to propagate a large flaw or the stress to cause linking of smaller flaws. Strength variability was correspondingly due to either the distribution of critical flaws or the variability in the spatial array of flaws. Fracture mechanics principles can be applied in understanding these results although in many cases a unique solution is not possible because of the nonidealized flaw structure in ceramics. Because of the difficulty in controlling the detailed microstructure of ceramics during fabrication, the attainment of uniform ceramic strengths is an extremely difficult goal.