Ultrasonic vibration technology has been widely applied in plastic forming processes due to its advantages of material properties improvement. In this study, a transverse ultrasonic vibration-assisted compression (TUVC) system with the range of vibration amplitude from 16 to 48 µm is developed to compress the difficult-to-deformation materials. The experiment found that the temperature of the compressed sample with the vibration amplitude of 38 µm arrived at 164 ℃, hence the current constitutive models are deficient for the description of TUVC deformation behavior with the large vibration amplitudes. The results show that the flow stress declines under the coupling action of volume effect and surface effect, especially the amplitude is larger than 38 µm. To accurately depict the constitutive behavior of titanium alloy under TUVC, a hybrid constitutive model considering the difference of softening mechanism was proposed based on crystal plasticity theory, and the predicted curves are in good agreement with experimental results. Finally, the microstructure further revealed the differences of softening mechanism in TUVC, and numerous secondary α phase was precipitated. Consequently, the studies provide an insight into the deformation mechanism of TUVC and promote the application of ultrasonic vibration-assisted forming for the difficult-to-deformation alloy.

超声波振动技术由于其材料性能改善的优点而被广泛应用于塑料成型工艺中。在这项研究中，开发了一种振幅范围为16至48 µm的横向超声振动辅助压缩（TUVC）系统，以压缩难变形的材料。实验发现，振动振幅为38 µm的压缩样品的温度达到164℃，因此当前的本构模型不足以描述大振幅的TUVC变形行为。结果表明，在体积效应和表面效应的耦合作用下，流动应力下降，尤其是振幅大于38 µm。为了准确描述TUVC下钛合金的本构行为，基于晶体可塑性理论，提出了一种考虑软化机理差异的混合本构模型，其预测曲线与实验结果吻合良好。最后，显微组织进一步揭示了TUVC中软化机理的差异，以及许多次要的α相沉淀。因此，这些研究为TUVC的变形机理提供了见识，并促进了超声振动辅助成形技术在难变形合金中的应用。