TA15钛合金高温变形过程的介观模拟计算

发布时间：2018-01-29 19:08

本文关键词： 晶体塑性 TA钛合金介观模拟　出处：《稀有金属材料与工程》2015年04期 　论文类型：期刊论文

【摘要】：以多晶体位错滑移及塑性流动机制为基础,探究了TA15钛合金在高温变形过程中介观层次上形变不均匀性和力学响应。基于率相关晶体塑性理论,建立了描述体心立方结构金属力学行为的本构模型,同时考虑了主滑移系和次滑移系的运动;确定了合理的材料本构参数,高温压缩实验与模拟得到的真应力-应变曲线基本一致。通过对TA15钛合金高温变形模拟结果进行分析,包括应力和应变分布、滑移系开动情况和晶界面积变化,得出:(1)由于晶粒几何及取向的随机性造成应力和应变分布非均匀性;(2)晶粒间相互作用的复杂性会导致各个滑移系开动的差异性;(3)形变程度越大,晶粒密度越大,晶界面积变化率越大。模拟结果为相变等显微组织演变及多尺度同步耦合提供了参考。
[Abstract]:Based on the mechanism of dislocation slip and plastic flow in polycrystal, the inhomogeneity of deformation and mechanical response of TA15 titanium alloy at the intermediate level during high temperature deformation were investigated, based on the rate-dependent theory of crystal plasticity. A constitutive model describing the mechanical behavior of bulk centered cubic structures is established, and the motion of the main and secondary slip systems is considered. Reasonable constitutive parameters were determined and the true stress-strain curves obtained by high temperature compression test were basically consistent with those obtained by simulation. The simulation results of high temperature deformation of TA15 titanium alloy were analyzed. Including the distribution of stress and strain, the moving of slip system and the change of grain boundary area, it is concluded that the distribution of stress and strain is inhomogeneous due to the randomness of grain geometry and orientation. (2) the complexity of the intergranular interaction will lead to the difference of the starting of each slip system; 3) the larger the deformation degree, the greater the grain density and the larger the grain boundary area change rate. The simulation results provide a reference for the microstructure evolution and multi-scale synchronous coupling such as phase transformation.
【作者单位】：合肥工业大学;
【基金】：国家自然科学基金资助(51175137) 安徽省自然科学基金资助(1308085JGD02)
【分类号】：TG146.23
【正文快照】： 多晶体材料宏观尺度上的均匀变形在介观尺度上往往表现为不均匀性,其宏观变化是微结构敏感的,依赖于其内部微结构,涉及晶体结构、晶界组态与分布、位错密度、滑移系和晶粒取向[1,2]。传统模型本构关系忽略多晶体微结构、各向异性性质和介观局部不均匀的影响,宏观力学响应表现

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