Study on constitutive behavior of Ti-45Nb alloy under transversal ultrasonic vibration-assisted compression
Study on constitutive behavior of Ti-45Nb alloy under transversal ultrasonic vibration-assisted compression
复制标题
Ti-45Nb合金横向超声振动辅助压缩本构行为研究
DOI：
10.1007/s43452-021-00186-7
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发表时间：
2021-02-16
影响因子：
4.4
通讯作者：
Chen, Wenliang
中科院分区：
文献类型：
--
作者：
Wang, Xingxing;Qi, Zhenchao;Chen, Wenliang
超声振动技术因其能改善材料性能的优点，在塑性成形工艺中得到了广泛的应用。本研究开发了一种振幅范围为16 ~ 48 μ m的横向超声振动辅助压缩系统，用于压缩难变形材料。实验发现，在振幅为38 μ m时，压缩试样的温度可达164 ℃，现有的本构模型难以描述大振幅下的变形行为。结果表明，在体积效应和表面效应的耦合作用下，流变应力下降，特别是幅度大于38 μ m。为了准确描述钛合金在TUVC下的本构行为，基于晶体塑性理论，提出了一种考虑软化机制差异的混合本构模型，预测曲线与实验结果吻合较好。最后，显微组织进一步揭示了TUVC软化机制的差异，并析出了大量的次生α相。研究结果有助于深入了解TUVC的变形机理，促进超声振动辅助成形技术在难变形合金中的应用。
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 mu m 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 mu m arrived at 164 celcius, 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 mu m. 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 alpha 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.