模具通道夹角对纯钛ECAP变形织构演变影响的有限元分析

发布时间：2018-04-20 14:52

本文选题：晶体塑性有限元模型 + 等径弯曲通道变形　；参考：《稀有金属》2015年11期

【摘要】：基于晶体塑性有限元模型,采用ABAQUS商业软件对纯钛在模具通道夹角分别为90°,120°,135°时的单道次等径弯曲通道变形(ECAP)的织构演变进行模拟,研究通道夹角对纯钛ECAP变形织构演变的影响。同时利用90°模具实现纯钛的单道次ECAP变形,并采用X射线衍射(XRD)技术获得变形前后的极图分布。将实验与模拟结果比较,以验证模拟结果的可靠性。通过对ECAP变形规律及试样点极图分析,发现90°模具挤压时,柱面织构完全取代初始织构,形成B和C_2两种柱面织构,这与XRD实验结果基本一致,表明了模型的可靠性。模具通道夹角为120°时,形成了C_1和C_2两种柱面织构,但以C_2织构为主。模具通道夹角为135°时,开始出现较弱的C_1织构,仍以C_2织构为主,但接近通道外角的下表面仍存在初始织构。通过对纯钛在不同通道夹角的ECAP模具中变形后的数据分析,得出模具通道夹角为90°时工艺最佳。
[Abstract]:Based on the crystal plastic finite element model (FEM), the texture evolution of pure titanium was simulated by ABAQUS commercial software when the channel angle of pure titanium was 90 掳/ 120 掳/ 135 掳respectively. The influence of channel angle on the evolution of deformation texture of pure titanium (ECAP) was studied. At the same time, the single-pass ECAP deformation of pure titanium was realized by 90 掳die, and the pole distribution before and after deformation was obtained by X-ray diffraction (XRD) technique. The experimental results are compared with the simulation results to verify the reliability of the simulation results. By analyzing the deformation law of ECAP and the point diagram of the specimen, it is found that the cylindrical texture completely replaces the initial texture and forms two kinds of cylindrical texture, B and C, which is consistent with the experimental results of XRD, which indicates the reliability of the model. When the angle of the die channel is 120 掳, two kinds of cylindrical texture, C _ S _ 1 and C _ S _ 2, are formed, but the main texture is C _ S _ 2 texture. When the angle of the die channel is 135 掳, the weak C _ S _ 1 texture begins to appear, which is still dominated by C _ S _ 2 texture, but the initial texture still exists on the lower surface near the outer corner of the channel. By analyzing the deformation data of pure titanium in ECAP die with different channel angle, the optimum process is obtained when the angle of channel is 90 掳.
【作者单位】：西安建筑科技大学冶金工程学院;
【基金】：国家自然科学基金面上项目(51474170) 陕西省教育厅专项基金项目(14JK1390)资助
【分类号】：TG379;TG146.23

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