Granular deformation mechanisms in semi-solid alloys
Granular deformation mechanisms in semi-solid alloys
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DOI：
10.1016/j.actamat.2011.04.038
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发表时间：
2011-07-01
期刊：
影响因子：
9.4
通讯作者：
Yasuda, H.
中科院分区：
文献类型：
--
作者：
Gourlay, C. M.;Dahle, A. K.;Yasuda, H.
采用剪切室实验和同步辐射X射线照相相结合的方法，原位研究了等轴半固态Al-15wt.%Cu合金的变形机制。直接证据表明，在晶体撞击后不久，固相分数的球形和等轴树枝状样品中的颗粒变形机制。结果表明，膨胀、拱形和堵塞发生在晶体尺度上，并在低置换速率下由于周期性的膨胀和压实而引起粘滑流动。球状和等轴树枝状样品中的颗粒变形被发现是相似的，如果长度按晶体大小来衡量，并且认为在晶体包层之间发生堆积。根据晶体重排和晶体变形之间的竞争，讨论了不同形态之间的流变性差异。(C)2011 Acta Materialia Inc.由爱思唯尔有限公司出版。保留所有权利。
Deformation mechanisms in equiaxed, partially solid Al-15 wt.% Cu are studied in situ by coupling shear-cell experiments with synchrotron X-ray radiography. Direct evidence is presented for granular deformation mechanisms in both globular and equiaxed-dendritic samples at solid fractions shortly after crystal impingement. It is demonstrated that dilatancy, arching and jamming occur at the crystal scale, and that these can cause stick-slip flow due to periodic dilation and compaction at low displacement rate. Granular deformation is found to be similar in globular and equiaxed-dendritic samples if length is scaled by the crystal size and packing is considered to occur among crystal envelopes. Rheological differences between the morphologies are discussed in terms of the competition between crystal rearrangement and crystal deformation. (C) 2011 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.