Abstract：Electromagnetic pulse welding (EMPW) technology has broad application prospects in the field of dissimilar metal connecting. Field shaper is an important part in the EMPW system. However, there are few researches on the influence of the structure of flat plate field shaper on its wording efficiency by changing the distribution of eddy currents. Therefore, the relationship among the structural parameters, eddy current distribution and wording efficiency of field shaper was explored from the basic principle of field shaper. The flat field shaper used with multi-turn coil was taken as the research object. The circuit-magnetic field coupling model of EMPW plates was established by COMSOL Multiphysics. Reflected the wording efficiency of the field shaper by calculating the maximum instantaneous magnetic flux density on the surface of the plate to be welded. The structural parameters that affected the effectiveness of the field shaper include height, upper and lower surface diameter, upper and lower hole diameter and gap angle α, The angle α were jointly determined by the upper and lower hole diameters. When the coil and sample to be welded were confirmed, the diameter of the upper and lower surfaces and the diameter of the lower hole were determined accordingly, which were 200 mm, 20 mm and 10 mm respectively according to the application scenarios of EMPW. When the diameter of the upper hole was 10 mm. The simulation result showed that as the height of the field shaper increased, the cancellation effect of the magnetic flux density generated by the induced eddy currents on the upper and lower surfaces of the field shaper gradually weakened, but the eddy current loss increased. So the working efficiency of field shaper first increased and then decreased with the increased of height, and it was the best at a height of 10 mm. There was bifurcation phenomenon of eddy current in the field shaper gaps, it could be divided into two parts: effective current and leakage current, and the effective current can be used for welding. The angle α had an important impact on the selection of the current path on the side of the gaps, which decided the proportion of effective current. The proportion of effective current continuously increased with the decrease of the angle α. When the height and lower hole diameter were both 10 mm, as the upper hole diameter increased, the total current decreased and the proportion of effective current continuously increased. So the efficiency of field shaper showed a trend of increasing first and then decreasing. When the upper hole diameter was better than that of lower hole, the angle α was an acute angle, the overall magnetic collection effect was better. And when α=45°, the efficiency of field shaper was the best. To verified the simulation results, the EMPW platform suitable for copper plate and aluminum plate was established, and different structural field shaper (acute angle, right angle and obtuse angle) were made. Welding experiments, tensile test and peeling experiments were carried out. The results showed that the tensile strength of the sample increased with the increased of voltage. The copper-aluminum sample welded with a sharp angle field shaper got the highest tensile strength, the largest effective welding area and the best welding effect. The welding effect of the right angle field shaper was middle, and the obtuse angle field shaper was the worst. The following conclusions can be drawn from the simulation and experiments: (1) As the height of the field shaper increases, the working efficiency fist increasing and then decreasing, and there is an optimal parameter for the height of the field shaper. (2) There was bifurcation phenomenon of eddy current in the field shaper gaps, and it’s divided into leakage current and effective current, the angle of field shaper gaps influence the current path selection and the ratio of effective current a lot. (3) As the upper hole diameter of field shaper increases, the total current decreases and the proportion of effective current continuously increases. Therefore, the field shaper effect shows a trend of increasing first and then decreasing.
李成祥, 沈婷, 吴浩, 周言, 米彦. 平板集磁器结构对涡流分布与集磁效果的影响规律[J]. 电工技术学报, 2023, 38(15): 4087-4096.
Li Chengxiang, Shen Ting, Wu Hao, Zhou Yan, Mi Yan. Influence of the Structure Parameters of the Flat Field Shaper on the Eddy Current Distribution and Magnetic Concentration Effect. Transactions of China Electrotechnical Society, 2023, 38(15): 4087-4096.
[1] 张望, 王于東, 李彦涛, 等. 基于双向电磁力加载的管件电磁翻边理论与实验[J]. 电工技术学报, 2021, 36(14): 2904-2911. Zhang Wang, Wang Yudong, Li Yantao, et al.Theory and experiment of tube electromagnetic flanging based on bidirectional electromagnetic force loading[J]. Transactions of China Electrotechnical Society, 2021, 36(14): 2904-2911. [2] 熊奇, 杨猛, 周丽君, 等. 双线圈吸引式板件电磁成形过程中的涡流竞争问题[J]. 电工技术学报, 2021, 36(10): 2007-2017. Xiong Qi, Yang Meng, Zhou Lijun, et al.Eddy currents competition in electromagnetic forming process of plates by double-coil attraction[J]. Transactions of China Electrotechnical Society, 2021, 36(10): 2007-2017. [3] Liao Zhigang, Li Chengxiang, Du Jian, et al.Design and experiments of double-switch electromagnetic pulse welding system[J]. Energy Reports, 2020, 6: 964-971. [4] Kapil A, Sharma A.Magnetic pulse welding: an efficient and environmentally friendly multi-material joining technique[J]. Journal of Cleaner Production, 2015, 100: 35-58. [5] 周言, 李成祥, 杜建, 等. 放电电压对镁-铝磁脉冲焊接中金属射流及结合界面的影响[J]. 电工技术学报, 2022, 37(2): 459-468, 495. Zhou Yan, Li Chengxiang, Du Jian, et al.Investigation on the effect of discharge voltage on metal jet and bonded interface in Mg-Al magnetic pulse welding[J]. Transactions of China Electrotechnical Society, 2022, 37(2): 459-468, 495. [6] 李成祥, 杜建, 周言, 等. 电磁脉冲板件焊接设备研制及镁/铝合金板焊接实验研究[J]. 电工技术学报, 2021, 36(10): 2018-2027. Li Chengxiang, Du Jian, Zhou Yan, et al.Development of electromagnetic pulse welding equipment for plates and experimental research on magnesium/aluminum alloy welding[J]. Transactions of China Electrotechnical Society, 2021, 36(10): 2018-2027. [7] Aizawa T, Okagawa K, Kashani M.Application of magnetic pulse welding technique for flexible printed circuit boards (FPCB) lap joints[J]. Journal of Materials Processing Technology, 2013, 213(7): 1095-1102. [8] Li Jishuai, Raoelison R N, Sapanathan T, et al.Assessing the influence of fieldshaper material on magnetic pulse welded interface of Al/Cu joints[J]. Procedia Manufacturing, 2019, 29: 337-344. [9] Yu Haiping, Li Chunfeng, Zhao Zhiheng, et al.Effect of field shaper on magnetic pressure in electromagnetic forming[J]. Journal of Materials Processing Technology, 2005, 168(2): 245-249. [10] Yan Ziqin, Xiao Ang, Cui Xiaohui, et al.Magnetic pulse welding of aluminum to steel tubes using a field-shaper with multiple seams[J]. Journal of Manufacturing Processes, 2021, 65: 214-227. [11] Kumar R, Kore S D.Experimental studies on the effect of different field shaper geometries on magnetic pulse crimping in cylindrical configuration[J].The International Journal of Advanced Manufacturing Technology, 2019, 105(11): 4677-4690. [12] Rajak A K, Kumar R, Basumatary H, et al.Numerical and experimental study on effect of different types of field-shaper on electromagnetic terminal-wire crimping process[J]. International Journal of Precision Engineering and Manufacturing, 2018, 19(3): 453-459. [13] Dang Haiqing, Yu Haiping.Improving the quality of Al-Fe tube joints manufactured via magnetic pulse welding using an inclined-wall field shaper[J]. Journal of Manufacturing Processes, 2022, 73: 78-89. [14] Deng Fangxiong, Cao Quanliang, Han Xiaotao, et al.Electromagnetic pulse spot welding of aluminum to stainless steel sheets with a field shaper[J]. The International Journal of Advanced Manufacturing Technology, 2018, 98(5): 1903-1911. [15] Zhang Hang, Liu Ning, Li Xiaoxiang, et al.A novel field shaper with slow-varying central hole for electromagnetic pulse welding of sheet metal[J].The International Journal of Advanced Manufacturing Technology, 2020, 108(7/8): 2595-2606. [16] Kinsey B, Nassiri A.Analytical model and experimental investigation of electromagnetic tube compression with axi-symmetric coil and field shaper[J]. CIRP Annals, 2017, 66(1): 273-276. [17] 李成祥, 石鑫, 周言, 等. 针对H型线圈的电磁脉冲焊接仿真及线圈截面结构影响分析[J]. 电工技术学报, 2021, 36(23): 4992-5001. Li Chengxiang, Shi Xin, Zhou Yan, et al.Electromagnetic pulse welding simulation for H-type coil and analysis of the influence of coil cross-sectional structure[J]. Transactions of China Electrotechnical Society, 2021, 36(23): 4992-5001. [18] 米彦, 芮少琴, 储贻道, 等. 基于阿基米德螺旋线圈的高变化率脉冲磁场发生器[J]. 高电压技术, 2017, 43(2): 578-586. Mi Yan, Rui Shaoqin, Chu Yidao, et al.Pulsed magnetic field generator with high-variation rate based on Archimedes spiral coil[J]. High Voltage Engineering, 2017, 43(2): 578-586. [19] 刘刚, 韩佳一, 丁健, 等. 高压电力电缆导体连接管的电磁脉冲成形研究[J]. 高电压技术, 2021, 47(3): 1109-1117. Liu Gang, Han Jiayi, Ding Jian, et al.Research on electromagnetic pulse forming of conductor connecting pipe of high voltage power cable[J]. High Voltage Engineering, 2021, 47(3): 1109-1117. [20] 聂鹏, 朱树峰, 王哲峰. 小直径管件电磁缩径集磁器特性研究[J]. 机械设计与制造, 2019(9): 38-41. Nie Peng, Zhu Shufeng, Wang Zhefeng.Experimental research on electromagnetic necking shaper used for pipe fittings with small diameter[J]. Machinery Design & Manufacture, 2019(9): 38-41. [21] 王哲峰, 姜孔明, 高铁军. 用于管件电磁缩径的螺旋槽集磁器结构参数研究[J]. 锻压技术, 2018, 43(12): 44-49. Wang Zhefeng, Jiang Kongming, Gao Tiejun.Research on structural parameters of spiral groove field shaper for electromagnetic reduction of tube[J]. Forging & Stamping Technology, 2018, 43(12): 44-49. [22] 李春峰, 张景辉, 赵志衡. 胀形用集磁器的实验研究[J]. 哈尔滨工业大学学报, 2000, 32(4): 107-109. Li Chunfeng, Zhang Jinghui, Zhao Zhiheng.Experimental study on magnetic collector for bulging[J]. Journal of Harbin Institute of Technology, 2000, 32(4): 107-109.
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