摘要
采用Gleeble-1500热模拟试验机在变形温度为900~1050℃、应变速率为0.1~10 s^(-1)的条件下,对TC11钛合金进行等温恒应变速率单轴压缩试验。组织观测结果表明,在热变形过程中,TC11钛合金存在明显的动态再结晶现象,变形温度分别为900℃和950℃时,再结晶晶粒尺寸随应变速率增加而先增大后减小;变形温度分别达1000℃和1050℃时,α相含量大量减少,组织演变中动态再结晶机制占主导,晶粒细化明显。为研究此现象对流变行为的影响,结合K-M位错密度模型与动态再结晶分数模型,建立了基于动态回复与动态再结晶现象的流动应力高温本构模型。将此本构模型预测结果与试验数据对比分析,相关性系数和平均相对误差分别为0.989和6.53%,表明所构建的考虑动态回复与动态再结晶的流动应力模型能够准确预测TC11钛合金热变形条件下的流动应力。
Gleeble-1500 thermal simulation testing machine was used to perform an isothermal constant strain rate uniaxial compression test for TC11 titanium alloy under a deformation temperature of 900~1050℃and strain rate of 0.1~10 s^(-1).The microstructure observation results show that a significant dynamic recrystallization phenomenon occurs in TC11 titanium alloy during the thermal deformation process.Under the deformation temperatures of 900℃and 950℃,the recrystallization grain size first increases and then decreases with increasing strain rate.Furthermore,as the deformation temperature reaches 1000℃and 1050℃,the content of theαphase significantly decreases,and the microstructure evolution is dominated by dynamic recrystallization,accompanied by obvious grain refinement.To study the effect of the dynamic recrystallization phenomenon on rheological behavior,a high-temperature constitutive model of flow stress based on dynamic recovery and dynamic recrystallization was constructed in combination with the K-M dislocation density model and dynamic recrystallization fraction model.By comparing the prediction results of the constitutive model with the test data,the correlation coefficient and average relative error are 0.989 and 6.53%,respectively,which suggests that the constructed flow stress model with dynamic recovery and dynamic recrystallization can accurately predict the flow stress of TC11 titanium alloy under thermal deformation.
作者
朱宁远
陈秋明
陈世豪
左寿彬
ZHU Ningyuan;CHEN Qiuming;CHEN Shihao;ZUO Shoubin(School of Mechanical and Electrical Engineering,Jiangxi University of Science and Technology,Ganzhou 341000,Jiangxi,China)
出处
《有色金属科学与工程》
CAS
北大核心
2024年第1期58-66,共9页
Nonferrous Metals Science and Engineering
基金
国家自然科学基金资助项目(51905241)
江西省自然科学基金资助项目(20202BABL214033)。
关键词
TC11钛合金
动态回复
动态再结晶
高温本构模型
K-M位错密度模型
TC11 titanium alloy
dynamic recovery
dynamic recrystallization
high-temperature constitutive model
K-M dislocation density model
作者简介
通信作者:朱宁远(1986-),博士,副教授,主要从事金属材料成形与控性一体化研究。E-mail:zhuningyuan@126.com。
