کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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1447586 | 988649 | 2010 | 10 صفحه PDF | دانلود رایگان |
We study spacing selection in directional solidification of Al–Cu alloys under transient growth conditions. New experimental results are presented which reveal that the mean dendritic spacing vs. solidification front speed exhibits plateau-like regions separated by regions of rapid change, consistent with previous experiments of Losert and co-workers. Quantitative phase-field simulations of directional solidification with dynamical growth conditions approximating those in the experiments confirm this behavior. The mechanism of this type of change in mean dendrite arm spacing is consistent with the notion that a driven periodically modulated interface must overcome an energy barrier before becoming unstable, in accord with a previous theory of Langer and co-workers.
Journal: Acta Materialia - Volume 58, Issue 18, October 2010, Pages 6115–6124