An. Kumar et Bf. Sorensen, Fracture resistance and stable crack-growth behavior of 8-mol%-yttria-stabilized zirconia, J AM CERAM, 83(5), 2000, pp. 1199-1206
The crack-growth behavior of a yttria-stabilized zirconia ceramic (8 mol% o
f cubic-phase yttria) was studied at room temperature. Double-cantilever-be
am specimens were loaded with pure bending moments in a specially designed
loading fixture inside an environmental scanning electron microscope. Crack
-growth data were obtained from truly sharp (arrested) cracks, bypassing in
terpretation problems that involve crack initiation from a machined notch.
The crack-growth study was conducted over a range of applied energy-release
rates that allowed crack arrest on one hand and fast fracture on the other
. Three energy-release-rate values were relevant initiation of crack growth
(3.5 J/m(2)), crack arrest (2.8 J/m(2)), and fast fracture (8.0 J/m(2)). A
t the macroscopic scale, subcritical crack growth occurred as a continuous
process. In situ observations revealed that, at the microscopic scale, crac
k growth occurred in small jumps. The fracture mode for stable crack growth
was identified to be transgranular.