Superplastic behavior of an ultrafine-grained Mg-13Zn-l.SSY alloy with a high volume fraction of icosahedral phases prepared by high-ratio differential speed rolling
An ultrafine-grained （UFG） Mg-13Zn-1.55Y alloy （ZW132） with a high volume fraction （7.4%） of icosa-hedral phase （/-phase, Mg3Zn6Y） particles was prepared by applying high-ratio differential speed rolling（HRDSR） on the cast microstructure following homogenization. The alloy exhibited excellent superp...
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| Published in: | 材料科学技术学报：英文版 Vol. 33; no. 9; pp. 919 - 925 |
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| Main Author: | |
| Format: | Journal Article |
| Language: | English |
| Published: |
2017
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| Subjects: | |
| Online Access: | Get full text |
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| Summary: | An ultrafine-grained （UFG） Mg-13Zn-1.55Y alloy （ZW132） with a high volume fraction （7.4%） of icosa-hedral phase （/-phase, Mg3Zn6Y） particles was prepared by applying high-ratio differential speed rolling（HRDSR） on the cast microstructure following homogenization. The alloy exhibited excellent superplas-ticity at low temperatures （tensile elongations of 455% and 1021% 473 K- 10^-3 S^-1 and 523 K- 10^-3 s^-1,respectively）. Compared with UFG Mg-9.25Zn~ 1.66Y alloy （ZW92） with a lower volume fraction of I-phaseparticles （4.1%）, which was prepared using the same processing routes, the UFG ZW132 alloy exhibited ahigher thermal stability of grain size. Rapid grain coarsening, however, occurred at temperatures beyond523 K, leading to a loss of superplasticity. The high-temperature deformation behavior of the HRDSR-processed ZW132 alloy could be well described assuming that the mechanisms of grain boundary slidingand dislocation climb creep competed with each other and considering that the grain-size was largelyincreased by accelerated grain growth at the temperatures beyond 523 K. |
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| Bibliography: | 21-1315/TG |
| ISSN: | 1005-0302 1941-1162 |