High-Temperature Creep of Y2O3-Stabilized ZrO2 |
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Authors: | M S SELTZER P K TALTY |
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Affiliation: | Battelle Columbus Laboratories, Columbus, OH 43201;Aerospace Research Laboratories, Wright-Patterson Air Force Base, OH 45433 |
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Abstract: | The compression creep behavior of Y2O3-stabilized ZrO2 (YSZ) was studied at temperatures to 2000 ° C. The function of Y2O3 content and grain size was tested in specimens with various impurity concentrations and porosity distributions. For relatively fine-grained specimens, creep rates increased with the 1.5 power of the applied stress at low stresses and with the third power at high stresses. The results for coarse-grained specimens can, in general, be fit by the cube dependence. The 1.5 power can be reduced to a linear dependence by correcting for an apparent threshold stress, which decreases with increasing temperature. Creep activation energies for YSZ are 128 ± 10 kcal/mol, independent of Y2O3 content, impurity level, grain size, and porosity distribution. In addition, over a broad range of temperatures and stresses the absolute values of the steady-state creep rates are influenced only by grain size and O2 partial pressure. |
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