中文摘要：

以钛合金在高温变形过程中的物理机制为基础，建立了钛合金高温变形时的位错密度和晶粒尺寸模型。将该微观组织模型应用于TC6合金的高温变形，并用遗传算法（GA）确定了模型中的8个材料常数。TC6合金的热模拟实验结果和定量金相实验结果证实：初生α相晶粒尺寸的计算值与实验值的平均误差小于15．3％。

英文摘要：

Microstructure evolution and modeling have been paid more attention in materials processing, in which it is a key to obtain the multi-scale microstructure models based on the physical metallurgy. In this paper, the two-scale microstructure models, including dislocation density and grain size of primary a phase in the high temperature deformation of titanium alloys, has been established. A set of models for microstructure evolution during high temperature deformation of the TC6 titanium alloy has been derived, in which 8 material constants has been optimized with the help of the genetic algorithm （GA） technique based on the experimental results of the TC6 titanium alloy. The maximum difference between the calculated and the experimental grain size of primary a phase of the TC6 titanium alloy is not more than .15.3%.