Premium
Fracture Resistance and Stable Crack‐Growth Behavior of 8‐mol%‐Yttria‐Stabilized Zirconia
Author(s) -
Kumar Amar N.,
Sørensen Bent F.
Publication year - 2000
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.1151-2916.2000.tb01354.x
Subject(s) - materials science , yttria stabilized zirconia , crack growth resistance curve , composite material , fracture mechanics , scanning electron microscope , cubic zirconia , fracture (geology) , crack closure , strain energy release rate , ceramic
The crack‐growth behavior of a yttria‐stabilized zirconia ceramic (8 mol% of cubic‐phase yttria) was studied at room temperature. Double‐cantilever‐beam 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 interpretation 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 ). At the macroscopic scale, subcritical crack growth occurred as a continuous process. In situ observations revealed that, at the microscopic scale, crack growth occurred in small jumps. The fracture mode for stable crack growth was identified to be transgranular.