ABSTRACT The uniaxial tensile experiments for Ti5Al2.5Sn alloy were performed at strain rates ranging from 10−3–10+3 s−1 and test temperatures of 153–873 K. Experimentally measured stress-strain responses indicate the yield strength exhibits positive strain-rate dependency, while the yield strength increases as the test temperature is decreased. To understand the thermomechanical coupling of dynamic plastic deformation, a specially developed single-tensile-pulse loading technique was used, and the isothermal stress-strain curves for the rates of 180 and 450 s−1 were obtained at temperatures of 203, 298 and 573 K. The plastic strain hardening measurements obtained here are essentially athermal and largely independent of strain rate, consistent with titanium and its alloys being bcc-structure-like in mechanical behaviour. Based on the experimentally obtained plastic deformation features of the alloy, the physically based Voyiadjis-Abed constitutive relationship was modified to model the dynamic tensile deformation of the Ti5Al2.5Sn alloy at low and high temperatures.

中文翻译：

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动态应变率对不同温度下 Ti5Al2.5Sn α-钛合金单轴拉伸变形的影响

摘要 Ti5Al2.5Sn 合金的单轴拉伸实验在 10-3-10+3 s-1 的应变速率和 153-873 K 的测试温度下进行。实验测量的应力-应变响应表明屈服强度表现出正应变-率依赖性，而屈服强度随着测试温度的降低而增加。为了理解动态塑性变形的热机械耦合，使用了专门开发的单拉伸脉冲加载技术，并在 203、298 和 573 的温度下获得了速率为 180 和 450 s-1 的等温应力-应变曲线K. 此处获得的塑性应变硬化测量基本上是非热的，并且在很大程度上与应变率无关，这与钛及其合金在机械行为上类似于 bcc 结构的情况一致。