Determination of grain boundary mobility during recrystallization by statistical evaluation of electron backscatter diffraction measurements
Determination of grain boundary mobility during recrystallization by statistical evaluation of electron backscatter diffraction measurements
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DOI：
10.1016/j.matchar.2016.04.024
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发表时间：
2016-07-01
影响因子：
4.7
通讯作者：
Molodov, D. A.
中科院分区：
文献类型：
--
作者：
Basu, I.;Chen, M.;Molodov, D. A.
影响金属系统中微结构设计途径的关键方面之一是晶界运动。本工作介绍了一种方法，通过该方法可以直接测量晶界迁移率与取向差的依赖性。该技术利用通过连续电子背散射衍射（EBSD）测量获得的数据集。实验EBSD测量结果进行了集体分析，从而数据集被用来获得晶界迁移率和晶粒纵横比相对于晶界取向不良。所提出的方法进一步验证使用元胞自动机（CA）模拟。单晶铝冷轧和划痕，以形核随机取向。随后在300摄氏度下退火导致晶粒在垂直于划痕的方向上生长成单一变形取向。观察到生长选择，其中具有接近Sigma 7 CSL取向关系（38度）的取向差的边界< 111 >迁移得相当快。所获得的边界迁移率分布表现出非单调行为，其最大值对应于围绕轴+/-4度的38度+/-2度的取向差< 111 >，这比随机大角度边界的迁移率值高10-100倍。与晶粒纵横比值的相关性表明，快速生长的晶粒显示出较强的生长各向异性。并就晶界性质对再结晶过程中晶界运动的影响进行了讨论。(C)版权所有© 2016 Elsevier Inc.
One of the key aspects influencing microstructural design pathways in metallic systems is grain boundary motion. The present work introduces a method by means of which direct measurement of grain boundary mobility vs. misorientation dependence is made possible. The technique utilizes datasets acquired by means of serial electron backscatter diffraction (EBSD) measurements. The experimental EBSD measurements are collectively analyzed, whereby datasets were used to obtain grain boundary mobility and grain aspect ratio with respect to grain boundary misorientation. The proposed method is further validated using cellular automata (CA) simulations. Single crystal aluminium was cold rolled and scratched in order to nucleate random orientations. Subsequent annealing at 300 degrees C resulted in grains growing, in the direction normal to the scratch, into a single deformed orientation. Growth selection was observed, wherein the boundaries with misorientations close to Sigma 7 CSL orientation relationship (38 degrees < 111 >) migrated considerably faster. The obtained boundary mobility distribution exhibited a non-monotonic behavior with a maximum corresponding to misorientation of 38 degrees +/- 2 degrees about < 111 > axes +/- 4 degrees, which was 10-100 times higher than the mobility values of random high angle boundaries. Correlation with the grain aspect ratio values indicated a strong growth anisotropy displayed by the fast growing grains. The observations have been discussed in terms of the influence of grain boundary character on grain boundary motion during recrystallization. (C) 2016 Elsevier Inc All rights reserved.