Premium
Scanning Acoustic Microscopy Observations of High‐Temperature Crack‐Bridging Mechanisms in Alumina
Author(s) -
Marrow James,
Luprano Vincenza,
Roberts Steve
Publication year - 1993
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.1151-2916.1993.tb04038.x
Subject(s) - materials science , scanning electron microscope , bridging (networking) , composite material , acoustic microscopy , microscopy , intergranular corrosion , microstructure , optics , computer science , computer network , physics
High‐purity, fine‐grained alumina showed a strong R ‐curve behavior for long cracks propagated at 1200°C. R ‐curve behavior was not observed at room temperature. A combined investigation using high‐frequency scanning acoustic microscopy and scanning electron microscopy of crack profiles demonstrated asperity contact in the crack wake at 1200°C. A microcrack zone was not observed. Crack bridging, resulting from intergranular subcritical crack propagation was considered to be responsible for the toughness increase with increased crack length.