双态组织Ti80合金的动态再结晶行为

Dynamic recrystallization behavior of Ti80 alloy with bimodal structure

摘要:

采用 Gleeble-1500 热模拟实验机对双态组织Ti80合金在变形温度为860-980℃、应变速率为 0.01~1变形条件下进行了热压缩模拟实验，研究了合金热变形过程中的流变应力行为，利用加工硬化率确定了不同变形条件下动态再结晶临界应变。结果表明，动态再结晶是Ti80合金热变形过程中的重要软化机制，并发现动态再结晶临界应变随温度的升高和应变速率的降低而减小。基于Z参数和改进后的Avrami方程，构建了Ti80合金动态再结晶临界应变与动力学模型。

Abstract:

The thermal compression tests of Ti80 alloy with bimodal microstructure was conducted at the deformation temperature of 860-980℃ and the strain rate of 0.01~1s^(-1)on the Gleeble-1500 thermal-mechanical simulator. The flow stress and dynamic recrystallization behavior of the alloy during hot deformation were investigated, the critical strain of dynamic recrystallization was determined with the help of the work hardening rate. The results show that dynamic recrystallization is an important softening mechanism during hot deformation of Ti80 alloy, and the critical strain of dynamic recrystallization decreases with increasing temperature and decreasing strain rate. Based on the Z parameter and the improved Avrami equation, the critical strain and kinetics model for dynamic recrystallization of Ti80 alloy were constructed.