纯钽等通道转角挤压织构演变数值模拟研究  

Numerical simulation study on texture evolution of pure tantalum during equal channel angular pressing

作　　者：杨西荣[1] 戴炎 刘晓燕[1] 罗雷[1] 王敬忠[1] 杨博海 YANG Xi-rong;DAI Yan;LIU Xiao-yan;LUO Lei;WANG Jing-zhong;YANG Bo-hai(School of Metallurgical Engineering,Xi′an University of Architecture and Technology,Xi′an 710055,China)

机构地区：[1]西安建筑科技大学冶金工程学院,陕西西安710055

出　　处：《塑性工程学报》2024年第12期1-8,共8页Journal of Plasticity Engineering

基　　金：国家自然科学基金资助项目(51474170)。

摘　　要：研究了纯钽在室温下的多道次等通道转角挤压(ECAP)变形的微观组织和织构演变规律,并通过建立粘塑性自洽模型对变形过程进行模拟。结果表明:4道次ECAP变形后的晶粒细化效果明显,平均晶粒尺寸由初始状态的约45μm减小到约0.9μm,位错密度显著增加,局部区域发生动态再结晶;预测的织构与实验观测结果吻合较好,C路径的应变方向反转会导致部分纤维织构组分在偶数道次时受到明显的抑制,此时以{112}面滑移为主;变形初期,J_(θ)、J_(θ)、F_(θ)、D1_(θ)和D2_(θ)组分都得到了发展,但都偏离了它们的理想位置;随着等效应变的增加,{110}_(θ)纤维的组分向<111>_(θ)纤维的组分过渡,共有组分(E,E)得到加强,由于晶粒的细化及位错密度的升高,最终大多数晶粒转到<111>方向。The microstructure and texture evolution laws of pure tantalum during multi-pass equal channel angular pressing(ECAP)at room temperature were studied,and the deformation process was simulated by establishing the viscoplastic self-consistent model.The re-sults show that the grain refinement effect after 4 passes ECAP deformation is obvious,the average grain size decreases from initial about 45μm to about 0.9μm,the dislocation density increases significantly,and dynamic recrystallization occurs in local areas.The predicted texture is in good agreement with the experimental result.The reversal of the strain direction of the C path can cause some fiber texture components to be significantly inhibited at even passes,and the{112}plane slip is dominant at this time.In the early stage of deformation,J_(θ),J_(θ),F_(θ),D1_(θ)and D2_(θ)components are developed,but all deviates from their ideal positions.With the increase of the equivalent strain,the composition of the{110}_(θ)fiber transits to the composition of the<111>_(θ)fiber,and the common component(E,E)is strengthened.Due to the refinement of the grains and the increase of the dislocation density,most of the grains eventually turn to the<111>direction.

关 键 词：等通道转角挤压 纯钽 粘塑性自洽模型 织构演变 

分 类 号：TG146.416[一般工业技术—材料科学与工程]