Deformation dynamics of pore-free Ti4+-doped and pure c-axis sapphire crystals
| Autor: | D. J. Michael, R. E. Tressler |
|---|---|
| Rok vydání: | 1974 |
| Předmět: |
Materials science
Condensed matter physics Mechanical Engineering Enthalpy Doping technology industry and agriculture Slip (materials science) Protein filament Crystallography Mechanics of Materials Ultimate tensile strength Sapphire General Materials Science Deformation (engineering) Single crystal |
| Zdroj: | Journal of Materials Science. 9:1781-1788 |
| ISSN: | 1573-4803 0022-2461 |
| DOI: | 10.1007/bf00541746 |
| Popis: | Single crystal alumina filaments undoped and Ti4+-doped, having the c-axis within 2° of the filament axis were plastically strained in constant strain-rate tensile experiments. The results of differential strain-rate and differential temperature tests were used to calculate the stress exponents in the strain-rate equation, the activation volumes, and the activation enthalpies. The relatively high values of the stress-exponents (6 to 7), the variations of the activation enthalpy with stress and temperature, and the magnitudes of the strain-independent activation volumes suggest overcoming the Peierls-Nabarro stress as the rate-limiting mechanism for plastic deformation of the alumina crystals. The microscopic observations of the deformed specimens are consistent with slip on the {10¯11} 〈¯1101〉 pyramidal system as reported in previous investigations of similar materials. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
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