Effect of nanoscale α2 precipitation on strain localisation in a two-phase Ti-alloy
Effect of nanoscale α2 precipitation on strain localisation in a two-phase Ti-alloy
复制标题
DOI：
10.1016/j.actamat.2017.02.068
复制
发表时间：
2017-05-01
期刊：
影响因子：
9.4
通讯作者：
Preuss, M.
中科院分区：
文献类型：
--
作者：
Lunt, D.;Busolo, T.;Preuss, M.
许多商业钛合金含有6wt%的铝，并且这些合金易于析出α（2）（Ti 3Al）。在这里，我们使用高分辨率数字图像相关（HR-DIC）结合电子背散射衍射（EBSD）研究和量化α（2）沉淀对具有等轴显微组织的Ti-6Al-4V应变局部化行为的影响。HR-DIC使我们能够量化应变局部化，这表明在1%的施加应变下，与不含α（2）的样品相比，在含有α（2）沉淀物的样品中，最大剪切应变方面的应变异质性约为两倍。所有可能的滑移系统的理论滑移迹线角计算使用电子背散射衍射（EBSD）取向数据和交叉相关的实验滑移迹线角测量从纳米尺度剪切应变图记录HR-DIC预测活动滑移域。已经发现，虽然滑动类型活动的频率是强烈依赖于纹理加载方向，实际剪切应变的贡献，从棱柱形滑移的α（2）沉淀的存在下，显着增加。该实验观察结果支持先前对α（2）沉淀物的反相边界（APB）能量的计算[1]，其中棱柱面上广泛解离的部分位错显示出比α（2）中基面上与剪切相关的APB能量更低的APB能量。(C)2017 Acta Materialia Inc.由Elsevier Ltd.出版。保留所有权利。
Many commercial Ti-alloys contain 6 wt% Aluminium and these alloys are prone to precipitation of alpha(2) (Ti3Al). Here, we investigate and quantify the effect of alpha(2) precipitation on strain localisation behaviour for Ti-6Al-4V with an equiaxed microstructure using High Resolution Digital Image Correlation (HR-DIC) in combination with Electron Back Scatter Diffraction (EBSD). HR-DIC has enabled us to quantify strain localisation, which shows that at 1% applied strain the strain heterogeneity in terms of maximum shear strain is about twice in the sample containing alpha(2) precipitates compared to the alpha(2)-free sample. Theoretical slip trace angles for all possible slip systems were calculated using Electron Back Scatter Diffraction (EBSD) orientation data and cross-correlated with experimental slip trace angles measured from nano scale shear strain maps recorded by HR-DIC to predict the active slip domain. It has been found that while slip type activity in terms of frequency is strongly dependent on texture in respect to loading direction, the actual shear strain contribution from prismatic slip does increase significantly in the presence of alpha(2) precipitation. This experimental observation supports previous calculations of Anti-Phase Boundary (APB) energies for alpha(2) precipitates [1] where widely dissociated partial dislocations on the prismatic plane show a lower APB energy than the APB energy associated with shearing on the basal plane in alpha(2). (C) 2017 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.