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利用Deform-3D软件对高铌TiAl合金包套锻造过程中的微观组织演变进行模拟。为得到模拟所需参数,在1100～1250℃和0.001～0.5 s-1的条件下对合金进行了热压缩试验。在所得试验数据的基础上,利用一种间接方法建立了合金的动态再结晶模型,并利用Avrami形式的方程对再结晶分数进行描述。采用Cingara硬化模型及所建立的再结晶分数模型构建了合金的流变应力本构模型。模拟结果显示,由于锻造过程中摩擦的存在、热量的损失以及简单单向镦粗变形的锻造方式,使得坯料中的微观组织分布不均匀。通过模拟结果与实验结果的比较,证明所建立的有限元模型能够有效地预测高铌TiAl合金在包套锻造过程中的组织演变。
Deform-3D software was used to simulate the microstructure evolution during the forging process of high niobium TiAl alloy. In order to obtain the required parameters for the simulation, the alloys were subjected to hot compression tests at 1100-1250 ° C and 0.001-0.5 s-1. Based on the experimental data obtained, a dynamic recrystallization model of the alloy was established by an indirect method, and the recrystallization fraction was described by the Avrami equation. The Cingara hardening model and the established recrystallization fractional model were used to establish the flow stress constitutive model of the alloy. The simulation results show that due to the existence of friction during the forging process, the loss of heat and the forging method of simple unidirectional upsetting deformation, the microstructure in the blank is not evenly distributed. The simulation results and experimental results show that the finite element model established can effectively predict the microstructure evolution of high niobium TiAl alloy during the forging process.