高铌TiAl合金包套锻造过程微观组织模拟(英文)  

Simulation of Microstructure for Hot Pack-Forging of a High Nb Containing TiAl Alloy

作　　者：程亮[1] 常辉[1] 唐斌[1] 寇宏超[1] 李金山[1] 

机构地区：[1]西北工业大学凝固技术国家重点实验室,陕西西安710072

出　　处：《稀有金属材料与工程》2014年第1期36-41,共6页Rare Metal Materials and Engineering

基　　金：National Fundamental Research Program of China(Project No.2011CB605502)

摘　　要：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。The Deform-3D software was employed to describe the microstructure evolution of a high Nb containing TiA1 billet （Ti-42A1-8Nb-0.2W-0.1Y） during its hot pack-forging. To obtain the simulation parameters, hot compression tests were performed at temperatures of 1100-1250 ℃ and strain rates of 0.00l-0.5 s-1. Dynamic recrystallization model was developed by using an undirected method, and the recrystallized volume fraction was described by an Avrami-type equation. The constitutive model of the flow stress of the alloy was established based on Cingara hardening equation and the dynamic recrystallization model. The simulated results indicate an inhomogeneous distribution of grain structure occurs due to friction, heat loss and single direction upsetting operation in forging process. The microstructure evolution of the present alloy during pack-forging is validated by comparing the simulated results with that of the experimental data. The result indicates that the implemented microstructure module can be effectively used to predict the microstructure evolution of the high Nb containing TiA1 alloy during pack-forging.

关 键 词：高铌TIAL合金 包套锻造 本构模型 动态再结晶 

分 类 号：TG319[金属学及工艺—金属压力加工]