Experimental and crystal plasticity studies of deformation and crack nucleation in a titanium alloy
Experimental and crystal plasticity studies of deformation and crack nucleation in a titanium alloy
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DOI：
10.1243/03093247jsa594
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发表时间：
2010-01-01
影响因子：
1.6
通讯作者：
Madrigal, C.
中科院分区：
文献类型：
--
作者：
Bache, M. R.;Dunne, F. P. E.;Madrigal, C.
本文介绍了晶体塑性建模的最新进展，以纳入非局部裂纹成核准则，并比较了近α钛（Ti）合金多晶的变形和裂纹成核的实验观察和模型预测。建立模型多晶，使其晶粒形貌和晶体学与实验中名义上一致，可以对结果进行直接解释和比较。采用电子散斑干涉法对大晶粒多晶样品进行了应变场测量。晶体塑性模型的预测结果与实验结果在与裂纹成核有关的一些重要特征上表现出了很强的一致性：裂纹成核的位置、裂纹跨越两个晶界时裂纹扩展的方向变化以及晶体取向在成核位置和扩展方向上的重要作用。在菌株异质性的建立和局部化方面也有很好的一致性；实验和晶体塑性预测均表明，非均质性在加载过程中较早形成，且局部化与裂纹成核位置密切相关。
This paper presents recent developments in crystal plasticity modelling to incorporate a non-local crack nucleation criterion and the comparison of experimental observations and model predictions for deformation and crack nucleation in a near-alpha titanium (Ti) alloy polycrystal. The model polycrystal was established so as to have grain morphology and crystallography nominally identical to that in the experiment, enabling direct interpretation and comparison of the results. The experimental measurements of strain fields were obtained using electronic speckle pattern interferometry on a large-grained polycrystalline sample.The crystal plasticity model predictions and experiments show strong agreement in a number of important features relating to crack nucleation: the location of crack nucleation, the direction changes in crack growth when the crack crosses two grain boundaries, and the important role of crystallographic orientation in nucleation site and in growth directions. There was also good agreement in the establishment of strain heterogeneity and in localization; both experiment and crystal plasticity predictions demonstrate that the heterogeneity is established early in the loading history and that the localization correlates closely with the crack nucleation site.