Effect of microvoids on microplasticity behavior of dual-phase titanium alloy under high cyclic loading(Ⅰ):Crystal plasticity analysis  

微孔洞对高周循环载荷作用下双相钛合金微塑性行为的影响(Ⅰ):晶体塑性分析

作　　者：Kai-di LI Xiao-ning HAN Bin TANG Meng-qi ZHANG Jin-shan LI 李凯迪;韩晓宁;唐斌;张梦琪;李金山(西北工业大学凝固技术国家重点实验室,西安710072;北京航空制造技术研究院,北京100024)

机构地区：[1]State Key Laboratory of Solidification Processing,Northwestern Polytechnical University,Xi’an 710072,China [2]Beijing Aeronautical Manufacturing Technology Research Institute,Beijing 100024,China

出　　处：《Transactions of Nonferrous Metals Society of China》2022年第2期513-523,共11页中国有色金属学报（英文版）

基　　金：the National Key Research and Development Program of China(No.2021YFB3702603).

摘　　要：A crystal plasticity finite element(CPFE)model was established and 2D simulations were carried out to study the relationship between microvoids and the microplasticity deformation behavior of the dual-phase titanium alloy under high cyclic loading.Results show that geometrically necessary dislocations(GND)tend to accumulate around the microvoids,leading to an increment of average GND density.The influence of curvature in the tip plastic zone(TPZ)on GND density is greater than that of the size of the microvoid.As the curvature in TPZ and the size of the microvoid increase,the cumulative shear strain(CSS)in the primaryα,secondaryα,andβphases increases.Shear deformation in the prismatic slip system is dominant in the primaryαphase.As the distance between the microvoids increases,the interactive influence of the microvoids on the cumulative shear strain decreases.建立二维晶体塑性有限元模型研究微孔洞与高周循环载荷作用下双相钛合金微塑性变形行为的关系。结果表明,几何必需位错(GND)倾向聚集于微孔洞周围,且导致平均GND密度升高。孔洞尖端塑性区域(TPZ)的曲率对GND密度的影响大于孔洞尺寸的影响。随着TPZ曲率和空洞尺寸的增大,初生α、次生α及β基体内的累积剪切应变增大。初生α相内柱面滑移系上的累积剪切应变主导其变形。当微孔洞间距增大时,微孔洞对累积剪切应变的影响减弱。

关 键 词：crystal plasticity dual-phase Ti alloy MICROVOIDS high cyclic loading cumulative shear strain geometrically necessary dislocation 

分 类 号：TG146.23[一般工业技术—材料科学与工程]