超塑性自由胀形温度对Ti_2AlNb板材壁厚分布的影响  

The influence of temperature for thickness distribution of Ti_2AlNb alloy sheet formed by superplastic free bulging

作　　者：马俊林[1] 刘雨生[1] 李萍[1] 薛克敏[1] 

机构地区：[1]合肥工业大学材料科学与工程学院,合肥230009

出　　处：《哈尔滨工业大学学报》2016年第5期172-177,共6页Journal of Harbin Institute of Technology

基　　金：国家自然科学基金资助项目(51175137);教育部新世纪优秀人才支持计划(NCET-13-0765)

摘　　要：为研究Ti_2AlNb合金高温超塑性自由胀形时的壁厚分布规律,对初始厚度均匀的Ti_2AlNb板材进行有限元模拟和试验研究.在胀形温度分别为910、930、950和970℃时,采用恒应变速率法对最终胀形试样的壁厚分布进行数值模拟,研究了胀形后试样的壁厚分布规律.结果表明:Ti_2AlNb板材在胀形后曲面壁厚分布不均匀,易呈现出不规则球形;胀形温度对曲面形状和壁厚具有较大的影响,变形温度对Ti_2AlNb板材超塑性自由胀形壁厚分布影响较大.在此基础上,引入温度敏感性指数n,对预测胀形壁厚的E-K模型进行修正.研究结果为Ti_2A1Nb合金在航空航天复杂薄壁结构件的超塑成形提供一定的参考依据.In order to research the thickness distribution laws of Ti2 A1Nb alloy when it is deformed with the superplastic free bulging in high temperature, the Ti2A1Nb sheet with an uniform initial thickness, has been studied by the finite element simulation and experiment in this paper. Laws of the limit bulged samples are experimented in the 910 ℃, 930℃, 950 ℃ and 970℃. And the thickness distribution of finally bulged samples are simulated numerically with the constant strain rate. It is found that, the spherical thickness distribution is uneven after bulging spheric ; and Ti2 A1Nb sheet is bulged into irregular spherical easily; and the temperature relatively effects the al shape and the thickness as well. The temperature can affect the thickness distribution of Ti2 AINb alloy sheet formed by superplastic free bulging, based on which the temperature sensitivity index n is considered to correct the E-K model which predicts the thickness of the bulged sheet. The study provides a reference basis for the superplastic deformation of complex thin-walled structures in aerospace of Ti2AINb alloy.

关 键 词：超塑性自由胀形 Ti_2AlNb合金 壁厚分布 温度 有限元 

分 类 号：TG306[金属学及工艺—金属压力加工]