电加热辅助微弯曲成形中纯钛箔材变形行为的晶粒尺寸效应  

Grain size effect on deformation behavior of pure titanium foils in resistance heating assisted microbending forming

作　　者：郑秋 清水徹英 古岛刚 杨明 ZHENG Qiu;SHIMIZU Tetsuhide;FURUSHIMA Tsuyoshi;YANG Ming(College of Mechanical&Electrical Engineering,Nanjing University of Aeronautics and Astronautics,Nanjing 210016,China;Graduate School of Systems Design,Tokyo Metropolitan University,Hino-shi,Tokyo 191-0065,Japan;Institute of Industrial Science,University of Tokyo,Meguro,Tokyo 153-8505,Japan)

机构地区：[1]南京航空航天大学机电学院,江苏南京210016 [2]东京都立大学系统设计学院,日本东京都日野市191-0065 [3]东京大学生产技术研究所,日本东京都目黑区153-8505

出　　处：《塑性工程学报》2022年第2期90-94,共5页Journal of Plasticity Engineering

基　　金：国家自然科学基金资助项目(52105363)。

摘　　要：研究了晶粒尺寸对纯钛箔材在电加热辅助微弯曲成形中变形行为的影响,为成形过程的设计提供了研究基础。对厚度为50μm的不同晶粒尺寸(2.7、4.5、14.7和24.5μm)的纯钛箔材分别在25、160、300和450℃温度下进行了电加热辅助微弯曲试验,对比了不同晶粒尺寸在不同成形温度下对回弹角和弯曲载荷的影响,并分析了其原因。结果表明,在各弯曲温度下,回弹角和弯曲载荷均随晶粒尺寸的增大而减小。此外,高温弯曲相对于室温弯曲的回弹角减小率随晶粒尺寸的增大而增大,高温弯曲时最大弯曲载荷的减小率也随晶粒尺寸的增大而增大。这是由高温弯曲时应变梯度的减小所引起的,并且由于大晶粒箔材的晶界比小晶粒箔材的晶界少,使大晶粒箔材在高温成形时变形更均匀,因而应变梯度的减小量比小晶粒箔材大。The effect of grain size on deformation behavior of pure titanium foils in resistance heating assisted microbending forming was studied, which provided a research basis for the design of forming process. Resistance heating assisted microbending tests of pure titanium foils with thickness of 50 μm and different grain sizes(2.7, 4.5, 14.7 and 24.5 μm) were carried out at temperatures of 25, 160, 300 and 450 ℃, respectively.The influence of grain size on the springback angle and bending load at different forming temperatures was compared, and the reasons were analyzed. The results show that both the springback angle and bending load decrease with the increase of grain size. In addition, the reduction rate of springback angle during bending at high temperature relative to the bending at room temperature increases with the increase of grain size, and the reduction rate of the maximum bending load also increases with the increase of grain size. This is caused by the decrease of strain gradient when bending at high temperature. Furthermore, the fewer grain boundaries of foils with large grains than those of foils with small grains contribute to a more uniform deformation. Thus, the decrease of strain gradient of foils with large grains is larger than that of foils with smaller grains.

关 键 词：电加热辅助微弯曲 纯钛箔材 晶粒尺寸效应 回弹角 弯曲载荷 应变梯度 

分 类 号：TG306[金属学及工艺—金属压力加工]