Abstract

A constitutive model for niobium with the effect of dynamic strain aging is proposed. The crystal structure of metals hugely influences the dynamic strain aging phenomenon and causes considerable alterations in the material’s macroscopic mechanical responses. Dynamic strain aging needs to be accounted for in a constitutive model to obtain accurate predictions of material’s thermo-mechanical behaviors during deformation. The proposed constitutive model attempts to describe the material’s flow stress responses during deformation by separating the flow stress contributions into the athermal component, thermal component, and dynamic strain aging component. Two different mathematical equations are proposed to model the dynamic strain aging component. The proposed model attempts to describe the mechanical response of niobium for a wide range of strain rates: from quasi-static loading (\(\dot{\varepsilon } = 0.001\,{\text{s}}^{ - 1}\)) to dynamic loading (\(\dot{\varepsilon } = 3300\, {\text{s}}^{ - 1}\)) across the temperature ranges 77 K–800 K.

Graphic Abstract

中文翻译：

---

铌动态应变时效的理论研究：温度和应变速率对流动应力的影响

摘要

提出了具有动态应变时效作用的铌本构模型。金属的晶体结构极大地影响了动态应变时效现象，并导致材料的宏观机械响应发生重大变化。需要在本构模型中考虑动态应变时效，以准确预测材料在变形过程中的热机械行为。拟议的本构模型试图通过将流动应力贡献分为非热分量，热分量和动态应变时效分量来描述材料在变形过程中的流动应力响应。提出了两个不同的数学方程来对动态应变时效分量进行建模。\（\ dot {\ varepsilon} = 0.001 \，{\ text {s}} ^ {-1} \））到动态加载（\（\ dot {\ varepsilon} = 3300 \，{\ text {s}} ^ {-1} \）））跨温度范围77 K–800K。

图形摘要