Investigations into the slip behavior of zirconium diboride
| Autor: | Brett Hunter, Nicholas De Leon, Gregory E. Hilmas, Gregory B. Thompson, Xiao-xiang Yu, Mark L. Weaver, Christopher R. Weinberger, William G. Fahrenholtz |
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| Rok vydání: | 2016 |
| Předmět: |
010302 applied physics
Zirconium diboride Materials science Activation barrier Condensed matter physics Mechanical Engineering Metallurgy 02 engineering and technology Slip (materials science) 021001 nanoscience & nanotechnology Condensed Matter Physics 01 natural sciences chemistry.chemical_compound chemistry Flexural strength Mechanics of Materials Stacking-fault energy 0103 physical sciences Low density General Materials Science Dislocation 0210 nano-technology |
| Zdroj: | Journal of Materials Research. 31:2749-2756 |
| ISSN: | 2044-5326 0884-2914 |
| DOI: | 10.1557/jmr.2016.201 |
| Popis: | The slip systems in ZrB2 flexural tested at 1000 °C and 1500 °C have been quantified. The dislocations in both samples were long and straight with a dislocation density of approximately 1013 m−2. The structure of the dislocations as well as the low density is in agreement with a ceramic that is hard and brittle and dislocation nucleation and motion is restricted. The low temperature slip systems were found to include c-prismatic slip— ${1 \mathord{\left/ {\vphantom {1 {3\left[{0001} \right]\left({\bar 1010} \right)}}} \right. \kern-\nulldelimiterspace} {3\left[{0001} \right]\left({\bar 1010} \right)}}$ —and a-pyramidal slip— ${1 \mathord{\left/ {\vphantom {1 {3\left[{11\bar 20} \right]\left({\bar 1101} \right)}}} \right. \kern-\nulldelimiterspace} {3\left[{11\bar 20} \right]\left({\bar 1101} \right)}}$ whereas the elevated temperature sample revealed a-basal slip— ${1 \mathord{\left/ {\vphantom {1 {3\left[{11\bar 20} \right]\left({0001} \right)}}} \right. \kern-\nulldelimiterspace} {3\left[{11\bar 20} \right]\left({0001} \right)}}$ . Density functional theory Generalized Stacking Fault Energy curves for perfect slip were calculated and agreed well with geometric considerations for slip, including interplanar spacing and planar packing. Though basal slip has the lowest fault energy, the presence of the other dislocation types is suggestive that the activation barrier is not a hindrance for the temperatures studied and is likely activated to increase the number of plastic degrees of freedom. |
| Databáze: | OpenAIRE |
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