摘要
To investigate the flow behavior of 2219 Al alloy during warm deformation, the thermal compression test was conducted in the temperature range of 483-573 K and the strain rate range of 0.001-5 s^-1 on a Gleeble-3500 thermomechanical simulation unit. The true stress-true strain curves obtained showed that the flow stress increased with the decrease in temperature and/or the increase in strain rate and the softening mechanism primarily proceeded via dynamic recovery. The modification on the conventional Arrhenius-type constitutive model approach was made, the material variables and activation energy were determined to be dependent on the deformation parameters. The modified flow stresses were found to be in close agreement with the experimental values. Furthermore, the activation energy obtained under different deformation conditions showed that it decreased with the rise in temperature and/or strain rate, and was also affected by the coupled effect of strain and strain rate.
为了研究2219铝合金的中温流变特性,利用Gleeble-3500热压缩实验机,在不同温度(483～573 K)及应变速率(0.001～5 s^(-1))的条件下进行热压缩实验。实验获得的真应力-真应变曲线表明,流变应力随着温度的降低和/或应变速率的升高而增大,且变形过程中的软化机制主要是动态回复。然后,基于材料变量和激活能对形变参数的依赖性,对传统的Arrhenius型本构模型进行参数修正。经验证,所建立修正的本构模型能很好地预测2219铝合金在中温变形条件下的流变应力。另外,基于此修正模型获得不同条件下的热激活能。激活能随温度和/或应变速率的升高而降低,且受应变和应变速率的耦合作用影响。
基金
Projects(U1637601,51405520,51327902) supported by the National Natural Science Foundation of China
Project(ZZYJKT2017-06) supported by State Key Laboratory of High Performance Complex Manufacturing of Central South University,China
