A detailed investigation was conducted of the dislocation structure formed within both the α and β phase of a Ti-6Al-4V alloy subjected to an early stage of cyclic deformation. The cyclic loading-unloading was carried out in tension between applied stress levels of 1100 and 100 MPa, the macroscopic yield stress (σ₀₂) being about 1205 MPa, at a strain rate of 2×10⁻³ s⁻¹ to 300 cycles, as part of an in-situ synchrotron experiment. The dislocation type, arrangement and density were examined post-mortem using transmission electron microscopy, complemented by the automatic determination of individual crystallite orientations through precession-enhanced nanobeam diffraction. The deformation took place entirely through dislocation glide and no evidence of deformation twinning was found within either of the constituent phases. The dislocation structure within the α phase was fairly similar to that formed during monotonic straining and no presence of periodic planar dislocation networks suggested in the literature was detected. Prismatic and basal slip were the dominant observed deformation modes, based on the calculated Schmid factor and critical resolved shear stress values reported in the literature. The <a>−type dislocations present after straining typically displayed a large screw component, with a majority of them having a pure screw character. There was also limited presence of <c+a> dislocations within the α phase and these were largely of a mixed type. Burgers vectors of the dislocations remaining after deformation within the β phase were also largely associated with the potential slip systems having high Schmid factor values and these dislocations mainly displayed a large screw component.

进行了详细研究，研究了Ti-6Al-4V合金的α相和β相中形成的位错结构经历了早期的循环变形。环状装卸于1100施加的应力水平和100兆帕，宏观屈服应力（σ之间张力进行₀₂为约1205兆帕），以2×10的应变速率^-3 小号^-1至300个循环，作为原位同步加速器实验的一部分。使用透射电子显微镜在验尸后检查位错类型，排列和密度，辅之以通过进动增强的纳米束衍射自动确定单个微晶的取向。变形完全通过位错滑移发生，在两个组成相中均未发现变形孪生的迹象。α相中的位错结构与单调应变过程中形成的位错结构非常相似，并且没有发现文献中暗示的周期性平面位错网络的存在。基于计算的施密特因子和文献中报道的临界解析剪切应力值，棱柱和基底滑动是观察到的主要变形模式。<a> 应变后出现的-型位错通常显示出较大的螺钉成分，其中大多数具有纯螺钉特性。在α相中还存在<c + a>位错，并且这些位错大部分是混合型。β相中变形后残留的位错的Burgers向量也与具有较高Schmid因子值的潜在滑移系统密切相关，这些位错主要显示出较大的螺杆分量。