In situ evaluation of dynamic precipitation during plastic straining of an Al-Zn-Mg-Cu alloy
In situ evaluation of dynamic precipitation during plastic straining of an Al-Zn-Mg-Cu alloy
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DOI：
10.1016/j.actamat.2012.01.002
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发表时间：
2012-03-01
期刊：
影响因子：
9.4
通讯作者：
Hutchinson, C. R.
中科院分区：
文献类型：
--
作者：
Deschamps, A.;Fribourg, G.;Hutchinson, C. R.
采用原位小角x射线散射测量方法系统地研究了Al-Zn-Mg-Cu合金在热力学试验中的析出与塑性的耦合关系。对两种不同初始沉淀条件下的预时效材料进行了研究。每个预时效状态都在160℃下应变，我们表明塑性诱导了加速的粗化动力学，我们根据析出相尺寸的演变来表征。这种加速度与塑性应变的程度相关，但与应变速率无关。实验数据有力地表明，加速动力学主要与塑性流动过程中空位的过饱和积累有关，这增加了有效扩散常数。(C) 2012材料学报Elsevier Ltd.出版。版权所有。
The coupling between precipitation and plasticity has been systematically investigated in an Al-Zn-Mg-Cu alloy using in situ small-angle X-ray scattering measurements during thermomechanical tests. Material pre-aged to two different initial precipitate conditions has been examined. Each pre-aged condition has been strained at 160 degrees C and we show that the plasticity induces an accelerated coarsening kinetics, which we characterize in terms of the evolution of the precipitate size. This acceleration is correlated with the degree of plastic strain, but does not depend markedly on strain rate. The experimental data strongly suggests that the accelerated kinetics is mainly linked with the accumulation of a supersaturation of vacancies during plastic flow that increases the effective diffusion constant. (C) 2012 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.