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Evolution of Stress Failure Resulting from High‐Temperature Stress‐Corrosion Cracking in a Hot Isostatically Pressed Silicon Nitride
Author(s) -
Wereszczak Andrew A.,
Ferber Mattison K.,
Kirkland Timothy P.,
More Karren L.,
Foley Michael R.,
Yeckley Russell L.
Publication year - 1995
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.1151-2916.1995.tb08625.x
Subject(s) - materials science , metallurgy , corrosion , creep , stress (linguistics) , stress corrosion cracking , silicon nitride , coalescence (physics) , ultimate tensile strength , grain boundary , yttrium , composite material , yttria stabilized zirconia , silicon , ceramic , microstructure , oxide , cubic zirconia , linguistics , philosophy , physics , astrobiology
Stress‐corrosion cracking in a commercially available, hot isostatically pressed (HIPed), yttria‐fluxed, silicon nitride was the prevalent mode of failure in specimens creepruptured at 1370°C. High‐temperature diffusional processes associated with oxygen were responsible for the creation of an advancing stress‐corrosion front that had formed at the specimen surface and advanced radially inward. The volume of material in the wake of the stress‐corrosion front possessed a high concentration of lenticular cavities at two‐grain boundaries, a high concentration of multigrain junction cavities, and large amorphous “pockets” in other multigrain junctions that were abnormally rich in oxygen and yttrium. The combination of tensile stress and the high concentration of cavities in the near‐surface volume of the material resulted in microcrack coalescence or the formation of a planar, stress‐corrosion crack . The concurrent growth of the stress‐corrosion front and crack during the tensile creep‐rupture tests ultimately led to stress‐induced failure.