High (10−3 s−1) densification rates at <0.25 homologous temperature in pressure assisted densification of nanocrystalline MgO: Effects of water absorption and grain size
| Autor: | Yasuhiro Kodera, Javier E. Garay, D.M. Dewitt |
|---|---|
| Rok vydání: | 2019 |
| Předmět: |
010302 applied physics
Materials science Absorption of water Mechanical Engineering Metals and Alloys 02 engineering and technology 021001 nanoscience & nanotechnology Condensed Matter Physics 01 natural sciences Grain size Lower temperature Nanocrystalline material Chemical engineering Mechanics of Materials 0103 physical sciences General Materials Science 0210 nano-technology Homologous temperature |
| Zdroj: | Scripta Materialia. 169:33-37 |
| ISSN: | 1359-6462 |
| DOI: | 10.1016/j.scriptamat.2019.04.020 |
| Popis: | We measured the real-time densification rates in the current activated pressure assisted densification (CAPAD) of nanocrystalline MgO. The rates of samples densified from powders with grain sizes ~40 nm are similar to those measured previously for other nanocrystalline materials while those from 29 nm powder are higher. Exposing the powders to a humid environment increases the densification rates and allows densification at lower temperatures. The densification rate curves of samples with absorbed water display two peaks implying two controlling mechanisms, while the dry samples display one. We attribute lower temperature densification to Mg(OH)2-MgO conversion and the higher to diffusion-controlled densification. |
| Databáze: | OpenAIRE |
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