Abstract We report crystallographic orientation dependent fracture behavior in tantalum single crystals with the tensile axes oriented close to [100], [110] and [111] directions. Three tantalum single crystals were deformed in quasi-static, uniaxial tension and their fracture surfaces were characterized. To understand different deformation modes and failure mechanisms, crystal plasticity-finite element (CP-FE) simulations were performed. Both experiments and CP-FE simulations showed strong strain localization and shear banding in the ~[100] specimen, little rotation and profuse necking in the ~[110] specimen, and significant crystal rotations associated with shear-dominated behavior in the ~[111] single crystal. In addition, voids were observed in fracture surfaces of ~[100] and ~[111] single crystals while the ~[110] specimen was void-free. The failure processes of these single crystals showed that dislocation boundaries are necessary for void nucleation in pure tantalum. This work demonstrates strong effects of crystallographic orientations in failure behaviors.

中文翻译：

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钽单晶中晶体取向相关的断裂行为

摘要 我们报告了拉伸轴接近 [100]、[110] 和 [111] 方向的钽单晶的晶体学取向相关断裂行为。三个钽单晶在准静态、单轴拉伸下变形，并对其断口进行了表征。为了了解不同的变形模式和失效机制，进行了晶体塑性有限元 (CP-FE) 模拟。实验和 CP-FE 模拟都显示~[100] 试样中的强应变局部化和剪切带，~[110] 试样中几乎没有旋转和大量颈缩，以及与~[111] 中剪切主导行为相关的显着晶体旋转] 单晶。此外，在~[100] 和~[111] 单晶的断口处观察到空隙，而~[110] 试样没有空隙。这些单晶的失效过程表明，位错边界是纯钽中空洞形核所必需的。这项工作证明了晶体取向对失效行为的强烈影响。