Compressive Strength and Damage Mechanisms in Partially Stabilized Zirconia.

The flow and fracture behavior of partially Mg stabilized zirconia subject to compressive loading was characterized for a wide range of strain rates and temperatures. It was found that the material exhibits plastic flow from 23C to 1200C, and that the flow stress curve is serrated. Contrary to results for A1203, SiC, and Si3N4, the strain rate dependence of compressive strength for PSZ does not correlate with the stress intensity dependence of subcritical crack growth velocity. These results, combined with the presence of an unusual type of deformation banding, have been interpreted in terms of plastic strain-induced, co-operative martensitic transformation of metastable precipitates. Additional work has performed as part of an effort to establish the role of grain boundaries and grain boundary chemistry in the deformation and fracture of PSZ. Initial work has involved Auger electron spectroscopy of Ca-stabilized PSZ. It was found that intergranular regions are enriched in silica and calcium, and that grain boundary facets were apparently coated by a thin, continuous second phase film. Author