Low-frequency vibration-assisted metal plastic forming is a novel promising technology, adopting a high-pressure-capability device compared to the ultrasonic vibration system. This work focuses on the low-frequency vibration assisted upsetting (LFVAU) process of Ti45Nb, to reduce the flow stress and crack initialization in the cold deformation of titanium alloy. The results show that the flow stress is significantly reduced by applying the vibration, and this stress reduction phenomenon becomes more obvious with larger frequency and amplitude. The vibration promotes the dislocation movement and grain rotation, resulting in dislocation annihilation in the shear band but dislocation concentration and low-angle grain boundary formation near the grain boundary in the large deformation zone. Therefore, more homogenous deformation occurred in LFVAU compared to the conventional quasi static upset (QUS) specimen, though the grain size is similar in the cylinders after QSU and LFVAU. Based on the above research results, the application of low-frequency vibration assisted processing technology in the field of aerospace will help to improve the plastic deformation quality, especially the riveting quality for Ti45Nb.

低频振动辅助金属塑性成形是一种新的有前途的技术，与超声波振动系统相比，它采用了高压能力装置。这项工作重点研究了 Ti45Nb 的低频振动辅助镦粗 (LFVAU) 工艺，以减少钛合金冷变形过程中的流动应力和裂纹初始化。结果表明，施加振动后流变应力显着降低，并且随着频率和振幅的增大，这种应力降低现象变得更加明显。振动促进了位错运动和晶粒旋转，导致剪切带中的位错湮灭，但在大变形区的晶界附近形成位错集中和小角度晶界。所以，与传统的准静态镦粗 (QUS) 试样相比，LFVAU 中发生了更均匀的变形，尽管 QSU 和 LFVAU 后圆柱体中的晶粒尺寸相似。基于以上研究成果，低频振动辅助加工技术在航空航天领域的应用将有助于提高塑性变形质量，尤其是Ti45Nb的铆接质量。