Long-term annealing of high purity aluminum single crystals: New insights into Harper-Dorn creep
| Autor: | K. K. Smith, Praveen Kumar, Michael E. Kassner |
|---|---|
| Rok vydání: | 2017 |
| Předmět: |
010302 applied physics
Materials science Condensed matter physics Annealing (metallurgy) Mechanical Engineering media_common.quotation_subject Metallurgy Materials Engineering (formerly Metallurgy) chemistry.chemical_element Frustration 02 engineering and technology 021001 nanoscience & nanotechnology Condensed Matter Physics 01 natural sciences chemistry Creep Mechanics of Materials Aluminium 0103 physical sciences Newtonian fluid General Materials Science 0210 nano-technology media_common |
| Zdroj: | Materials Science and Engineering: A. 705:1-5 |
| ISSN: | 0921-5093 |
| Popis: | Single crystals of 99.999% and 99.9999% pure aluminum were annealed at high elevated temperatures (0.98T m ) for relatively long times of up to one year, the longest in the literature. Remarkably, the dislocation density remains relatively constant at a value of about 10 9 m −2 over a period of one year. The stability suggests some sort of “frustration” limit. This has implications towards the so-called “Harper-Dorn creep” that generally occurs at fairly high temperatures (e.g. > 0.90T m ) and very low stresses. It is possible that ordinary five-power-law creep occurs within the tradition Harper-Dorn regime with very low initial dislocation densities in aluminum. Higher initial dislocation densities, such as with this annealing study, may lead to Harper-Dorn (Newtonian) creep. |
| Databáze: | OpenAIRE |
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