TC21钛合金动态再结晶行为的元胞自动机模拟

Cellular automata simulation of dynamic recrystallization behavior of TC21 titanium alloy

摘要:

为研究热加工工艺不同变形参数对TC21钛合金塑性成形过程中微观组织的影响，本文利用Gleeble-3500型热模拟试验机进行等温恒应变速率热压缩实验，研究了TC21钛合金在不同变形条件下的热变形行为；并以TC21钛合金在热压缩过程中微观组织演变为基础，通过对TC21钛合金的位错密度模型、再结晶形核和晶粒长大模型的推导，建立了元胞自动机模型，并基于元胞自动机模型对TC21钛合金β单相区变形过程中的动态再结晶行为进行了模拟和验证。结果表明：该合金的流变应力随着温度的降低和应变速率的升高而增大；结合元胞自动机模拟结果分析得，在β单相区内该合金动态再结晶体积分数与变形温度成正比，而与应变速率成反比。

Abstract:

In order to study the effect of different deformation parameters of thermal processing on the microstructure of TC21 titanium alloy during plastic forming, this paper uses the Gleeble-3500 thermal simulation testing machine to conduct isothermal constant strain rate thermal compression experiments, and studies the TC21 titanium alloy under different deformation conditions. The thermal deformation behavior of TC21 titanium alloy; and based on the microstructure evolution of TC21 titanium alloy during thermal compression, through the derivation of dislocation density model, recrystallization nucleation and grain growth model of TC21 titanium alloy, a cellular automatic Based on the cellular automata model, the dynamic recrystallization behavior of TC21 titanium alloy during deformation in the β single-phase region was simulated and verified. The results show that the flow stress of the alloy increases with the decrease of temperature and the increase of strain rate; according to the analysis of cellular automata simulation results, the dynamic recrystallization volume fraction and deformation temperature of the alloy in the β single-phase region proportional to the strain rate and inversely proportional to the strain rate.