The role of diffusion creep in the superplastic deformation of 3 mol% yttria stabilized tetragonal zirconia
The deformation behavior of high purity superplastic 3YTZ is characterized by n = 2, p = 3 at high stresses and n = 3 and p = 1 at low stresses. A recent analysis by Berbon and Langdon, based on a model by Arzt et al., is capable of rationalizing some of the experimental data in terms of diffusion creep from a limited number of discrete sources/sinks. An approach involving rearrangement caused by grain growth can explain the retention of an equiaxed grain size even during diffusion creep. The lack of appropriate diffusion data severely restricts the validity of conclusions based on a good match between experimental data and theoretical predictions. Based on the model by Arzt et al., a critical grain size is developed beyond which conventional Coble diffusion creep will operate. Experiments at coarser grain sizes are necessary to validate the approach based on diffusion creep. A complete analysis for deformation in 3YTZ must account for the influence of impurity content on the transition from n {approximately} 2 at high stresses to n {approximately} 3 at low stresses.
- Research Organization:
- Indian Inst. of Science, Bangalore (IN)
- OSTI ID:
- 20013339
- Journal Information:
- Scripta Materialia, Vol. 42, Issue 3; Other Information: PBD: Jan 2000; ISSN 1359-6462
- Country of Publication:
- United States
- Language:
- English
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