脉冲电场辅助碳素钢极薄带拉伸变形的本构模型和微观组织演变  

Constitutive Model and Microstructural Evolution for Tensile Behavior of Carbon Steel Ultrathin Strip under Pulsed Electric Field

作　　者：任忠凯 李赫 许雅楠 程前 冯浩 王涛[1,2] REN Zhongkai;LI He;XU Yanan;CHENG Qian;FENG Hao;WANG Tao(College of Mechanical and Vehicle Engineering,Taiyuan University of Technology,Taiyuan 030024;Engineering Research Center of Advanced Metal Composites Forming Technology and Equipment,Ministry of Education,Taiyuan University of Technology,Taiyuan 030024;China National Heavy Machinery Research Institute Co.,Ltd,Xi’an 710018)

机构地区：[1]太原理工大学机械与运载工程学院,太原030024 [2]太原理工大学先进金属复合材料成形技术与装备教育部工程研究中心,太原030024 [3]中国重型机械研究院股份公司,西安710018

出　　处：《机械工程学报》2024年第6期245-260,共16页Journal of Mechanical Engineering

基　　金：国家自然科学基金重点(U22A20188);山西省科技创新人才团队专项(202304051001025);国家自然科学基金(52275361);海安太原理工大学先进制造与智能装备产业研究院开放研发(2023HA-TYUTKFYF038);山西省基础研究计划(202103021223070)资助项目。

摘　　要：08AL碳素钢极薄带材在微机电及微系统领域有着广泛的应用前景,但随着厚度的减小其塑性变形能力成为掣肘其应用的痛点。将脉冲电场集成到08AL碳素钢极薄带拉伸试验中,探究拉伸变形中电致塑性效应对极薄带变形能力和微观组织演变的影响规律。基于试验结果,建立一种改进的Johnson-Cook本构模型,用来定量分析电致塑性效应中焦耳热效应和非热效应对材料流动应力的影响规律。基于材料硬化子程序VUMAT开发电场辅助拉伸有限元模型,分析不同成形参数下的应力和应变特性,并确定试样微观结构表征的位置。试验结果表明,在施加1.50 A/mm^(2)的电流时,试样抗拉强度较室温拉伸降低16.5%,伸长率提高32.1%。此外,微观表征结果表明,在平均电流密度为1.50 A/mm^(2)的条件下,极薄带在塑性变形阶段不断细化晶粒并促进晶内和晶界处位错滑移,使其变形抗力降低,塑性性能提高。因此,脉冲电场辅助08AL碳素钢极薄带变形,有望显著提高其成形极限,拓宽其应用领域。08AL carbon steel ultrathin strip has a wide application prospect in the field of the microelectromechanical system.However,the application of the material is limited by the plastic deformation capacity because of the decrease in thickness.In this paper,a pulsed electric field was integrated into tensile tests to investigate the influence of the electroplastic effect on the deformability and microstructural evolution of the 08AL carbon steel ultrathin strip.Based on the experimental results,a modified Johnson-Cook constitutive model was developed to quantify the Joule thermal and non-thermal effects on the flow stress of the material.A finite element model of the electric field-assisted tensile test based on the custom material hardening subroutine VUMAT was developed to analyze the stress and strain characteristics under different forming parameters and locate the position of the microstructural characterization of the specimens.The experimental results showed that the tensile strength at a current density of 1.50 A/mm^(2) decreased by 16.5%compared to the result at room temperature,while the elongation increased by 32.1%.In addition,the result of microstructural characterization revealed that the grains were refined,and the dislocations slipped within the grains and at grain boundaries under the average current density of 1.50 A/mm^(2).Therefore,the forming method assisted by the pulsed electric field for the 08AL carbon steel ultrathin strip is expected to significantly enhance its forming limits and broaden its application areas.

关 键 词：08AL碳素钢 脉冲电流 Johnson-Cook本构模型 微观表征 抗拉强度 

分 类 号：TG113[金属学及工艺—物理冶金]