极低频电脉冲处理对Al-Zn-Mg-Cu铝合金力学性能的影响规律与机理  

Effect of Extremely Low Frequency Pulse Current Treatment on the Mechanical Properties of Al-Zn-Mg-Cu Aluminum Alloy

作　　者：宋燕利[1,2,3] 郝川川 宁世儒 吴文林 刘鹏 SONG Yanli;HAO Chuanchuan;NING Shiru;WU Wenlin;LIU Peng(Hubei Key Laboratory of Advanced Technology for Automotive Components,Wuhan University of Technology,Wuhan 430070;Hubei Collaborative Innovation Center for Automotive Components Technology,Wuhan University of Technology,Wuhan 430070;Hubei Engineering Research Center for Green&Precision Material Forming,Wuhan University of Technology,Wuhan 430070;Dongfeng(Wuhan)Industry Co.,Ltd.,Wuhan 430040)

机构地区：[1]武汉理工大学现代汽车零部件技术湖北省重点实验室,武汉430070 [2]武汉理工大学汽车零部件技术湖北省协同创新中心,武汉430070 [3]武汉理工大学湖北省材料绿色精密成形工程技术研究中心,武汉430070 [4]东风(武汉)实业有限公司,武汉430040

出　　处：《机械工程学报》2022年第10期68-77,共10页Journal of Mechanical Engineering

基　　金：国家重点研发计划(2020YFA0714900);国家自然科学基金(51975440);湖北省重点研发计划(2020BAB143);新能源汽车科学与关键技术学科创新引智基地(B17034);教育部创新团队发展计划(IRT_17R83)资助项目。

摘　　要：电流辅助塑性成形是国际先进制造领域的研究热点,也是高强轻质合金精确成形制造的重要发展方向。研究极低频电脉冲对7075-T6铝合金力学性能的影响规律。结果表明,通过电脉冲辅助拉伸,7075-T6铝合金抗拉强度降低,试样断后延伸率最高可提升32.3%,且电流密度和持续时间与应力降值之间可建立线性关联关系。揭示电-力耦合时机对铝合金塑性性能的影响机制,在弹性变形阶段施加电脉冲,高速移动电子流会破坏原子间结合力,导致裂纹源提前出现,使铝合金塑性性能降低;而在塑性变形阶段施加电脉冲,高速移动电子流会促进位错运动,提升铝合金塑性性能。研究结果有助于推进高强铝合金在航空航天、舰船、高铁、汽车等领域的广泛应用。Current-assisted plastic forming is a research hotspot in the field of international advanced manufacturing,and it is also an important development direction for precision forming and manufacturing of high-strength lightweight alloys.The effect of extremely low frequency electric pulse on the mechanical properties of 7075-T6 aluminum alloy is studied.The results show that the tensile strength of 7075-T6 aluminum alloy is reduced by electric pulse-assisted stretching,the elongation of the sample after fracture can be increased by 32.3%,and a linear relationship can be established between the current density and duration and the stress drop.The mechanism of the influence of the timing of electrical-mechanical coupling on the plastic properties of aluminum alloys is revealed.When electrical pulses are applied during the elastic deformation stage,high-speed moving electron flow will destroy the bonding force between atoms,leading to the early appearance of crack sources and reducing the plastic properties of aluminum alloys.While applying electrical pulses during the plastic deformation stage,the high-speed moving electron flow will promote the movement of dislocations and improve the plastic performance of aluminum alloy materials.The research results will help promote the wide application of high-strength aluminum alloys in aerospace,ships,high-speed rail,automobiles and other fields.

关 键 词：电塑性 高强铝合金 力学性能 电-力耦合时机 

分 类 号：TG156[金属学及工艺—热处理]