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Transformation and Microcrack Toughening as Complementary Processes in ZrO 2 ‐Toughened Al 2 O 3
Author(s) -
RÜHLE M.,
CLAUSSEN N.,
HEUER A. H.
Publication year - 1986
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.1151-2916.1986.tb07405.x
Subject(s) - toughening , materials science , tetragonal crystal system , monoclinic crystal system , composite material , residual stress , stress field , stress (linguistics) , crystallography , toughness , crystal structure , structural engineering , chemistry , finite element method , linguistics , philosophy , engineering
Both tetragonal ( t ) and monoclinic ( m ) ZrO 2 particles in ZrO 2 ‐toughened Al 2 O 3 can give rise to toughening. In the stress field of propagating cracks, the t ‐ZrO 2 particles can undergo the stress‐induced t → m transformation, and the residual stresses around already‐transformed m ‐ZrO 2 particles can cause microcracking. The t ‐ZrO 2 particles transformed in crack tip stress fields do not, however, also cause appreciable microcracking. The toughening increments via these distinct mechanisms are comparable. It appears that optimally fabricated Zr0 2 ‐toughened Al 2 O 3 's should contain a mixture of t ‐ and m ‐ZrO 2 .