J. Lankford et al., THE ROLE OF PLASTICITY AS A LIMITING FACTOR IN THE COMPRESSIVE FAILURE OF HIGH-STRENGTH CERAMICS, Mechanics of materials, 29(3-4), 1998, pp. 205-218
The behavior of aluminum oxide under compressive loading is investigat
ed over a wide range in strain rate and degrees of confinement. It is
shown that plastic flow can be generated in Al2O3 at all strain rates
if confinement is sufficient to prevent premature failure via microfra
cture. Moreover, plastic flow is itself a source of microfracture, and
the threshold for multiple slip apparently constitutes the practical
ultimate strength for the ceramic. Thus, for sufficiently fine-grained
alumina tested under optimum conditions, no confinement is required t
o generate plastic flow, at which stress the material fails via disloc
ation-induced general microfracture. (C) 1998 Published by Elsevier Sc
ience Ltd. All rights reserved.