Research of Dynamic Characteristics in Electromagnetic Attraction Forming of AZ31 Magnesium Alloy Tube
Xiong Qi1,2, Zhu Xinhui1,3, Zhao Xiang1,3, Fan Liping4
1. Hubei Provincial Engineering Technology Research Center for Power Transmission Line China Three Gorges University Yichang 443002 China; 2. Wuhan National High Magnetic Field Center Huazhong University of Science and Technology Wuhan 430074 China; 3. College of Electrical Engineering & New Energy China Three Gorges University Yichang 443002 China; 4. Yichang Power Supply Company State Grid Hubei Electric Power Corporation Yichang 443002 China
Abstract：Electromagnetic forming (EMF) technology can effectively improve the forming limit of light alloys at room temperature, suppress the spring-back of the workpiece, and reduce wrinkling. It has been widely used in the plastic processing of aluminum alloy workpieces. However, compared with aluminum alloys, magnesium alloys have lower electrical conductivity and higher yield strength, so conventional EMF technology can not satisfy the plastic processing of magnesium alloy workpieces at room temperature. Recently, some scholars used high-conductivity alloys as driving plates or heating devices to assist in forming. However, the tooling was complex, and the forming quality needed to be guaranteed. It is not even suitable for small tube forming. Therefore, this paper proposes an electromagnetic attraction forming method for magnesium alloy tubes at room temperature. By establishing a finite element simulation model, the feasibility of the forming scheme, the discharge and electromagnetic parameters, and the workpiece deformation were studied. Firstly, AZ31B magnesium alloy tubes with an inner diameter of 10 mm, a length of 100 mm, and a thickness of 2 mm are selected. The dual-frequency discharge current method is used to generate attractive forces to drive the forming of the tube. Secondly, due to the extremely fast and complex electromagnetic forming, it is necessary to use simulation to explore the relationship between the parameters in the attractive electromagnetic forming process in detail. Finally, a finite element model has been developed considering the influence of tube displacement and deformation. The method realizes the full coupling between the electromagnetic fields and workpiece deformation. Simulation results show that the electromagnetic forming process can be divided into three stages: the stage before the short pulse current is turned on, the deformation stage, and the vibration stage. Changing the long-pulse voltage Us or the short-pulse voltage Uf can change the time-space distribution of electromagnetic parameters at point O and ultimately regulate the motion state of the tube. During the short-pulse current conduction stage, the electromagnetic parameters at point O have opposite signs, and the tube is subjected to a repulsive force. When Us is 9.4 kV and Uf is 13 kV, the tube is radially contracted by 0.27 mm, the final deformation area dent marks appear, and the deformation flatness is poor. In the deformation stage, the electromagnetic parameters at point O have the same sign, and the attractive force deforms the tube. When Uf is 13 kV, Us increases from 4.4 kV to 8.4 kV, and the action time of the attractive force in the deformation stage will become longer. The final radial expansion displacement of the tube will become larger. When Us is 8.4 kV and Uf is raised from 13 kV to 23 kV, the electromagnetic force and radial expansion velocity of point O in the deformation stage increase. However, the final displacement at 23 kV is only 5.84 mm, much lower than 7.13 mm at 21 kV. Uf was raised from 21 kV to 23 kV (0.5 kV intervals) to study this phenomenon. In the vibration stage, the peak shrinkage radial velocity at 21 kV and 21.5 kV were 12.8 m/s and 13.4 m/s, respectively, and the peak shrinkage velocity increased to 32.9 m/s at 22.5 kV. At this time, the repulsive force will dominate the motion state of the tube in the vibration stage, so the final deformation effect is not good. The following conclusions can be drawn: (1) In practical engineering, whether Us will cause necking in the workpiece before the short pulse is turned on should be considered. (2) Since Us has a lower upper limit, increasing Us is more effective than increasing Uf. It can improve the deformation effect of the tube fitting. (3) The upper limit of Uf will be determined by the motion state of the tube fitting in the vibration stage. That is, the velocity movement trend of the tube fitting in this stage should be roughly the same. If the shrinkage speed is significantly increased, Uf cannot be further increased.
[1] 潘复生, 蒋斌. 镁合金塑性加工技术发展及应用[J]. 金属学报, 2021, 57(11): 1362-1379. Pan Fusheng, Jiang Bin.Development and application of plastic processing technologies of magnesium alloys[J]. Acta Metallurgica Sinica, 2021, 57(11): 1362-1379. [2] Zhang Jianyue, Jian Yongxin, Zhao Xuzhe, et al.The tribological behavior of a surface-nanocrystallized magnesium alloy AZ31 sheet after ultrasonic shot peening treatment[J]. Journal of Magnesium and Alloys, 2021, 9(4): 1187-1200. [3] Medina J, Garces G, Pérez P, et al.High temperature mechanical behaviour of Mg-6Zn-1Y alloy with 1 wt % calcium addition: reinforcing effect due to I-(Mg3Zn6Y1) and Mg6Zn3Ca2 phases[J]. Journal of Magnesium and Alloys, 2020, 8(4): 1047-1060. [4] Cui Xuejun, Ning Chuangming, Zhang Guangan, et al.Properties of polydimethylsiloxane hydrophobic modified duplex microarc oxidation/diamond-like carbon coatings on AZ31B Mg alloy[J]. Journal of Magnesium and Alloys, 2021, 9(4): 1285-1296. [5] Psyk V, Risch D, Kinsey B L, et al.Electromagnetic forming—a review[J]. Journal of Materials Pro- cessing Technology, 2011, 211(5): 787-829. [6] Wu Zelin, Cao Quanliang, Fu Junyu, et al.An inner- field uniform pressure actuator with high performance and its application to titanium bipolar plate for- ming[J]. International Journal of Machine Tools and Manufacture, 2020, 155: 103570. [7] 邱立, 李彦涛, 苏攀, 等. 电磁成形中电磁技术问题研究进展[J]. 电工技术学报, 2019, 34(11): 2247-2259. Qiu Li, Li Yantao, Su Pan, et al.Research on electromagnetic problems in electromagnetic forming process[J]. Transactions of China Electrotechnical Society, 2019, 34(11): 2247-2259. [8] 熊奇, 唐红涛, 王沐雪, 等. 2011年以来电磁成形研究进展[J]. 高电压技术, 2019, 45(4): 1171-1181. Xiong Qi, Tang Hongtao, Wang Muxue, et al.Research progress of electromagnetic forming tech- nique since 2011[J]. High Voltage Engineering, 2019, 45(4): 1171-1181. [9] 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]. Transa- ctions of China Electrotechnical Society, 2021, 36(10): 2007-2017. [10] Cao Quanliang, Xia Liangyu, Li Xian, et al.The importance of coil conductivity and eddy current effects in the analysis of electromagnetic forming process[J]. High Voltage, 2022, 7(2): 390-404. [11] Xiong Qi, Huang Hao, Xia Liangyu, et al.A research based on advance dual-coil electromagnetic forming method on flanging of small-size tubes[J].The Inter- national Journal of Advanced Manufacturing Tech- nology, 2019, 102(9/10/11/12): 4087-4094. [12] 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. [13] Xiong Qi, Li Zhe, Tang Jianhua, et al.A flexible and economical method for electromagnetic flanging of tubes with field shapers[J]. The International Journal of Advanced Manufacturing Technology, 2021, 116(3/4): 1169-1177. [14] Qiu Li, Yu Yijie, Yang Yuqi, et al.Analysis of electromagnetic force and experiments in electro- magnetic forming with local loading[J]. International Journal of Applied Electromagnetics and Mechanics, 2018, 57(1): 29-37. [15] 邱立, 余一杰, 聂小鹏, 等. 管件电磁胀形过程中的材料变形性能问题与电磁力加载方案[J]. 电工技术学报, 2019, 34(2): 212-218. Qiu Li, Yu Yijie, Nie Xiaopeng, et al.Study on material deformation performance and electromag- netic force loading in electromagnetic tube expansion process[J]. Transactions of China Electrotechnical Society, 2019, 34(2): 212-218. [16] Xiong Qi, Tang Hongtao, Wang Muxue, et al.Design and implementation of tube bulging by an attractive electromagnetic force[J]. Journal of Materials Pro- cessing Technology, 2019, 273: 116240. [17] Ouyang Shaowei, Wang Chen, Li Changxing, et al.Improving the uniformity and controllability of tube deformation via a three-coil forming system[J]. The International Journal of Advanced Manufacturing Technology, 2021, 114(5/6): 1533-1544. [18] 王紫叶, 杨猛, 熊奇. 电磁成形过程中线圈温升及结构优化[J]. 电工技术学报, 2021, 36(18): 3891-3901. Wang Ziye, Yang Meng, Xiong Qi.Coil temperature rise and structure optimization in electromagnetic forming[J]. Transactions of China Electrotechnical Society, 2021, 36(18): 3891-3901. [19] 徐俊瑞, 王元丰, 王宇阳, 等. 镁合金板材磁脉冲成形研究进展[J]. 精密成形工程, 2021, 13(5): 10-21. Xu Junrui, Wang Yuanfeng, Wang Yuyang, et al.Research progress of magnetic pulse forming of magnesium alloy sheet[J]. Journal of Netshape Forming Engineering, 2021, 13(5): 10-21. [20] 徐俊瑞. AZ31镁合金板材磁脉冲成形性能研究[D]. 哈尔滨: 哈尔滨工业大学, 2013. [21] Uhlmann E, Jurgasch D.New impulses in the forming of magnesium sheet metals[C]//Proceeding 1st Inter- national Conference on High Speed Forming, Dortmund, 2004: 229-241. [22] Ulacia I, Arroyo A, Eguiy I, et al.Warm electro- magnetic forming of AZ31B magnesium alloy sheet[C]// Proceeding 4th International Conference on High Speed Forming, Ohio, 2010:159-168. [23] 孟正华, 黄尚宇, 胡建华, 等. 镁合金板材温热电磁复合成形试验研究[J]. 机械工程学报, 2011, 47(10): 38-42. Meng Zhenghua, Huang Shangyu, Hu Jianhua, et al.Experimental research on warm and electromagnetic hybrid forming of magnesium alloy sheet[J]. Journal of Mechanical Engineering, 2011, 47(10): 38-42. [24] Xu Junrui, Xie Xueyun, Wen Zhisheng, et al.Deformation behaviour of AZ31 magnesium alloy sheet hybrid actuating with Al driver sheet and temperature in magnetic pulse forming[J]. Journal of Manufacturing Processes, 2019, 37: 402-412. [25] Xu Junrui, Wang Yuyang, Wen Zhisheng, et al.Electromagnetic impacting medium forming (EIMF): a new method forming process for magnesium alloy sheet[J]. The International Journal of Advanced Manufacturing Technology, 2020, 109(1/2): 553-563. [26] 唐红涛. 基于吸引式电磁力的金属管件电磁胀形设计与实现[D]. 宜昌: 三峡大学, 2019. [27] 杜立蒙. 可调阻尼系数下的电磁成形工件变形及线圈焦耳热特性研究[D]. 武汉: 华中科技大学, 2020. [28] Xiong Qi, Tang Hongtao, Deng Changzhen, et al.Electromagnetic attraction-based bulge forming in small tubes: fundamentals and simulations[J]. IEEE Transactions on Applied Superconductivity, 2018, 28(3): 1-5. [29] Cao Quanliang, Lai Zhipeng, Xiong Qi, et al.Electromagnetic attractive forming of sheet metals by means of a dual-frequency discharge current: design and implementation[J]. The International Journal of Advanced Manufacturing Technology, 2017, 90(1/2/3/4): 309-316. [30] 熊奇, 周丽君, 杨猛, 等. 单脉冲电磁成形中洛伦兹力在时间上的双向竞争关系及其对成形效果的影响[J]. 电工技术学报, 2022, 37(14): 3453-3463. Xiong Qi, Zhou Lijun, Yang Meng, et al.The two- way competitive relationship of Lorentz force in time in single pulse electromagnetic forming and its influence on forming effect[J]. Transactions of China Electrotechnical Society, 2022, 37(14): 3453-3463.
2023, Vol. 38 
