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Anomalous Defects and Dynamic Failure of Armor Ceramics
Author(s) -
Bakas M.P.,
Greenhut V.A.,
Niesz D.E.,
Quinn G. D.,
McCauley J. W.,
Wereszczak A. A.,
Swab J. J.
Publication year - 2004
Publication title -
international journal of applied ceramic technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.4
H-Index - 57
eISSN - 1744-7402
pISSN - 1546-542X
DOI - 10.1111/j.1744-7402.2004.tb00172.x
Subject(s) - materials science , ceramic , armour , composite material , fracture (geology) , silicon carbide , classification of discontinuities , sintering , mathematical analysis , mathematics , layer (electronics)
The ballistic performance of state‐of‐the‐art silicon carbide armor material can exhibit a fairly wide variability in certain test configurations, which, it is proposed, may be due to the presence of large (>0.1 mm), rare defects, termed, herein, “anomalous” defects. SiC rubble resulting from ballistic tests was examined, as were quasi‐static test samples. Ballistic fragment fracture surfaces revealed large carbonaceous defects that seemed to affect fracture path and mode. Low‐strength biaxial flexure samples demonstrated similar defects (>0.1 mm) as failure origins. Carbonaceous defects similar in appearance but smaller in size were also found at the fracture origins of SiC bend bars. Frequently, alumina inclusions were found within the carbonaceous discontinuities. These alumina inclusions may cause the graphitic regions to form during sintering. The random distribution of such large, rare carbonaceous discontinuities from sample‐to‐sample, as well as batch‐to‐batch variability, may explain high ballistic variability for SiC armor ceramics.