细晶TC4钛合金的动态再结晶行为及数值模拟

Dynamic recrystallization behavior and numerical simulation of fine grain TC4 titanium alloy

摘要:

采用实验和有限元模拟相结合的方法，研究了经连续变断面循环挤压制备的细晶TC4钛合金热加工过程中的动态再结晶（DRX）行为。通过实验得到的真应力-应变曲线，建立了细晶TC4钛合金的临界应变模型和DRX动力学模型，并基于所建立的DRX模型，采用DEFORM-3D软件对其热压缩过程进行了模拟。结果表明:热压缩工艺参数对细晶TC4合金的DRX行为有显著影响；随着变形温度的升高和应变速率的降低，动态再结晶的体积分数（XDRX）及其晶粒尺寸均增大；随着应变的增大，变形区的等效应变和区域范围均增大；合金变形时，XDRX的实验值与其模拟值的相关性为0.9762，表明所建立的模型具有较高的精度。

Abstract:

The dynamic recrystallization (DRX) behavior of fine-grain TC4 titanium alloy prepared by continuous variable cross-section recycled extrusion during hot working was investigated by combining experiment and finite element simulation. The critical strain and DRX dynamic models of fine-grain TC4 titanium alloy were established based on the true stress-strain curves obtained by the experiment. The material properties were defined based on the DRX models, and the thermal compression process was simulated by DEFORM-3D software. The results show that the DRX behavior of fine grain TC4 is significantly affected by thermal compression processing parameters; the volume fraction of dynamic recrystallization (XDRX) and the grain size are increased with increasing deformation temperature and decreasing strain rate; the equivalent strain and range of the deformation zone are increased simultaneously with increasing strain; the correlation between the experimental value and the simulated value of XDRX is 0.9762, which indicates the high accuracy of the established model.