The present work investigates dislocation structures developed within both the α and β phase of a Ti–6Al–4V alloy undergoing cyclic tensile straining. The cyclic loading-unloading was performed using the stress levels of 830 and 580 MPa (R∼0.7) at a strain rate of 2 × 10^-3 s^-1 to 15125 cycles, as part of a synchrotron in-situ experiment. The macroscopic yield stress was about 950 MPa. The dislocation arrangement, type and density were studied post-mortem employing transmission electron microscopy, together with the automatic determination of crystal lattice orientations via precession nanobeam diffraction. The deformation took place exclusively through dislocation slip and no presence of deformation twins was detected within either of the studied phases. The α phase dislocation structure displayed some similarity to that reported for monotonic deformation and no evidence of the formation of regular planar dislocation networks, proposed in the literature, has been found. The prevalent deformation modes were prismatic and basal glide, based on the experimentally determined Burgers vectors together with the global Schmid factor and reported critical resolved shear stress values. The <a>-type dislocations observed after deformation generally possessed a large screw component, with most of them being of a pure screw type. There were also some <c+a> dislocations present within the α phase and these typically displayed a mixed character. Dislocation Burgers vectors present after straining within the β phase frequently deviated from the Schmid factor rule and these dislocations were often wavy and largely possessed a significant screw component.

目前的工作研究了在经历循环拉伸应变的 Ti-6Al-4V 合金的 α 和 β 相中形成的位错结构。循环加载-卸载使用 830 和 580 MPa (R∼0.7) 的应力水平，应变速率为 2 × 10 ^-3 s ^-1到 15125 个循环，作为同步加速器原位实验的一部分。宏观屈服应力约为 950 MPa。使用透射电子显微镜对位错排列、类型和密度进行了验尸研究，并通过进动纳米束衍射自动确定晶格取向。变形仅通过位错滑移发生，并且在任何一个研究阶段中都没有检测到变形孪晶的存在。α 相位错结构与单调变形报告的结构有些相似，并且没有发现文献中提出的规则平面位错网络形成的证据。普遍的变形模式是棱柱形和基底滑动，基于实验确定的 Burgers 矢量以及全局 Schmid 因子和报告的临界解析剪切应力值。变形后观察到的<a>型位错一般具有较大的螺旋分量，其中大部分为纯螺旋型。α相中还存在一些<c+a>位错，这些位错通常表现出混合特征。在 β 相内应变后出现的位错 Burgers 矢量经常偏离施密德因子规则，并且这些位错通常是波浪形的并且主要具有显着的螺旋分量。α相中还存在一些<c+a>位错，这些位错通常表现出混合特征。在 β 相内应变后出现的位错 Burgers 矢量经常偏离施密德因子规则，并且这些位错通常是波浪形的并且主要具有显着的螺旋分量。α相中还存在一些<c+a>位错，这些位错通常表现出混合特征。在 β 相内应变后出现的位错 Burgers 矢量经常偏离施密德因子规则，并且这些位错通常是波浪形的并且主要具有显着的螺旋分量。