INSITU MEASUREMENTS OF BRIDGED CRACK INTERFACES IN THE SCANNING ELECTRON-MICROSCOPE

被引:195
作者
RODEL, J
KELLY, JF
LAWN, BR
机构
[1] Ceramics Division, National Institute of Standards and Technology, Gaithersburg, Maryland
关键词
bridging; cracks; pullout; scanning electron microscopy; toughness;
D O I
10.1111/j.1151-2916.1990.tb06454.x
中图分类号
TQ174 [陶瓷工业]; TB3 [工程材料学];
学科分类号
0805 ; 080502 ;
摘要
A device for in situ SEM examination of crack propagation during loading of compact tension specimens is described, with a specific demonstration on an alumina ceramic. The device facilitates direct qualitative observations of the inception and subsequent frictional pullout of grain‐localized bridges at the crack interface. Quantitative data on the bridging mechanism are obtained from measurements of the crack‐opening displacements behind the crack tip. The crack profile is found to be closer to linear than parabolic at the bridged interface. Deconvolution of these crack‐opening data allow for an evaluation of the closure tractions operative at the crack walls within the bridging zone, and thence the R‐curve. Copyright © 1990, Wiley Blackwell. All rights reserved
引用
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页码:3313 / 3318
页数:6
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