Deformation, dislocation evolution and the non-Schmid effect in body-centered-cubic single- and polycrystal tantalum
Deformation, dislocation evolution and the non-Schmid effect in body-centered-cubic single- and polycrystal tantalum
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DOI：
10.1016/j.ijplas.2023.103529
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发表时间：
2021-09
影响因子：
9.8
通讯作者：
Seunghyeon Lee;Hansohl Cho;C. Bronkhorst;R. Pokharel;D. Brown;B. Clausen;S. Vogel;V. Anghel;G. T. Gray;J. Mayeur
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作者：
Seunghyeon Lee;Hansohl Cho;C. Bronkhorst;R. Pokharel;D. Brown;B. Clausen;S. Vogel;V. Anghel;G. T. Gray;J. Mayeur
提出了一种基于物理信息的连续晶体塑性模型，用于阐明体心立方（bcc）钽的变形机制、位错演化和非Schmid效应，体心立方（bcc）钽被广泛用作机械和热极端条件下的关键结构材料。我们表明，由介观位错动力学模拟提供信息的统一结构建模框架能够在准静态（10−3s−1）到极端应变率（5000 s−1）以及在单晶和多晶水平的低温（77 K）到高温（873 K）下捕获钽的大非弹性行为的显著特征。我们还提出了预测能力的材料中的微观结构演变的模型。为此，我们在单晶水平上研究了位错相互作用对滑移活动、不稳定性和非Schmid行为的影响。在此基础上，对多晶钽试样在应变增加过程中的织构演化和位错密度增长进行了原位测量。数值模拟结果也支持，建模框架是能够捕捉的主要特征的多晶行为在广泛的应变，应变速率和温度。在单晶和多晶水平的理论，实验和数值计算结果提供了关键的洞察底层的微观和宏观的响应和它们之间的关系，在这类重要的耐火体心立方材料进行大的非弹性变形的物理图片。
A physically-informed continuum crystal plasticity model is presented to elucidate deformation mechanisms, dislocation evolution and the non-Schmid effect in body-centered-cubic (bcc) tantalum widely used as a key structural material for mechanical and thermal extremes. We show the unified structural modeling framework informed by mesoscopic dislocation dynamics simulations is capable of capturing salient features of the large inelastic behavior of tantalum at quasi-static (10−3s−1) to extreme strain rates (5000 s−1) and at low (77 K) to high temperatures (873 K) at both single- and polycrystal levels. We also present predictive capabilities of the model for microstructural evolution in the material. To this end, we investigate the effects of dislocation interactions on slip activities, instability and the non-Schmid behavior at the single crystal level. Furthermore,ex situmeasurements on crystallographic texture evolution and dislocation density growth are carried out for polycrystal tantalum specimens at increasing strains. Numerical simulation results also support that the modeling framework is capable of capturing the main features of the polycrystal behavior over a wide range of strains, strain rates and temperatures. The theoretical, experimental and numerical results at both single- and polycrystal levels provide critical insight into the underlying physical pictures for micro- and macroscopic responses and their relations in this important class of refractory bcc materials undergoing large inelastic deformations.