Microstructure and high temperature deformation of an ultra-fine grained ECAP AA7075 aluminium alloy
| Autor: | Petr Harcuba, Kryštof Turba, Miroslav Cieslar, P. Málek |
|---|---|
| Rok vydání: | 2013 |
| Předmět: |
Pressing
Materials science Metallurgy Metals and Alloys Superplasticity engineering.material Deformation (meteorology) Condensed Matter Physics Microstructure 7075 aluminium alloy Deformation mechanism visual_art Materials Chemistry Aluminium alloy visual_art.visual_art_medium engineering Physical and Theoretical Chemistry Ultra fine |
| Zdroj: | International Journal of Materials Research. 104:3-10 |
| ISSN: | 2195-8556 1862-5282 |
| DOI: | 10.3139/146.110833 |
| Popis: | An AA 7075 aluminium alloy with an ultra-fine grained structure was prepared through equal channel angular pressing (ECAP) at pressing temperatures TECAP of 120, 170, and 220 °C. A decrease in TECAP from 220 to 120 °C was found to lead to a more pronounced refinement of the microstructure and to worse stability of the microstructure – the onset of grain coarsening was displaced to lower temperatures. The material pressed with the highest TECAP exhibited superplastic behaviour at temperatures close to 400 °C and grain boundary sliding was identified as the dominant operating deformation mechanism. The materials prepared with both of the lower TECAP exhibited only enhanced ductility of about 200 %, however this behaviour was observed at temperatures as low as 200 °C. It was found that this “low temperature superplasticity” resulted from a combined operation of grain boundary sliding at selected grain boundaries and glide of lattice dislocations. |
| Databáze: | OpenAIRE |
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