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Fracture Resistance Behavior of Highly Anisotropic Silicon Nitride
Author(s) -
Ohji Tatsuki,
Hirao Kiyoshi,
Kanzaki Shuzo
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.tb09095.x
Subject(s) - materials science , fracture toughness , indentation , silicon nitride , composite material , anisotropy , silicon , fracture (geology) , nitride , toughness , fracture mechanics , crack growth resistance curve , crack closure , metallurgy , optics , physics , layer (electronics)
The R ‐curve behavior was characterized by the Vickers indentation flaw technique, for highly anisotropic silicon nitride, a silicon nitride whose fibrous grains are highly aligned. The measured crack lengths ranged from 30 to 500 μm. The fracture resistance of a conventional self‐reinforced silicon nitride was determined for comparison using the same procedures. While in the self‐reinforced material several hundred micrometers of crack extension were required to obtain a high fracture toughness, the highly anisotropic material exhibited a high toughness from the beginning of the measured crack length range with little increase in the following range. It is suggested that the toughness of the highly anisotropic material steeply rises in a very short crack extension, which is advantageous in avoiding catastropic fractures.