Research Status of Surface Damage in Rails for Electromagnetic Launchers

doi:10.12382/bgxb.2022.0128

Abstract

Abstract:

Rails and armatures are critical components in electromagnetic rail launchers that convert electrical energy into kinetic energy. Due to high current, powerful magnetic fields, high relative speeds, intense heat, and immense pressure, these components inevitably experience material loss. This article provides a comprehensive review of domestic and international research conducted over the past few decades on surface damage to rails in electromagnetic rail launchers. The surface damage is mainly categorized into four types: grooving, gouging, transition ablation, and erosion wear. Each type exhibits distinct characteristics and occurs at different locations, resulting in varying degrees of material loss. Based on this, scientists put forward theories and models to explain and confirm the observed damage through experiments. To mitigate rail damage, structure, material and drive current waveform are modified. However, due to the deeply coupled system, extreme working conditions, limited measurements and the lack of valid experiments, few research about wear erosion has been reported. To understand the damage mechanism better, develop effective optimization strategies and unravel the process of damage evolution, the measurement and modeling methods should be improved.

Key words: electromagnetic rail launcher, material loss, electromagnetic launch, armature/rail contact

ZHANG Jiawei, LU Junyong, TAN Sai, LI Bai, ZHANG Yongsheng. Research Status of Surface Damage in Rails for Electromagnetic Launchers[J]. Acta Armamentarii, 2023, 44(7): 1908-1919.

Figures/Tables 12

Fig.1 Typical grooving damage appearance[4]

Fig.2 Typical gouging damage appearance[15]

Fig.3 Typical transition damage appearance[23]

Fig.4 Rail situation after 3 shots

Fig.5 Rail surface damage graph

Fig.6 Interference contact pressure distribution[33]

Fig.7 Current distribution[51]

Fig.8 Two kinds of solid armatures

Fig.9 Current distribution in different types of rails[66]

Fig.10 Two types of series-connected augmented EM launchers[68]

Fig. 11 Armature with lubricant storage[43]

Fig.12 Armatures before and after launch [77]

References 78

[1]	马伟明, 鲁军勇. 电磁发射技术[J]. 国防科技大学学报, 2016, 38(6): 1-5.
	MA W M, LU J Y. Electromagnetic launch technology[J]. Journal of National University of Defense Technology, 2016, 38(6):1-5. (in Chinese)
[2]	王莹, 肖峰. 电炮原理[M]. 北京: 国防工业出版社, 1995.
	WANG Y, XIAO F. The theory of electric gun[M]. Beijing: National Defense Industry Press, 1995. (in Chinese)
[3]	WATT T, STEFANI F, CRAWFORD M, et al. Investigation of damage to solid-armature railguns at startup[J]. IEEE Transactions on Magnetics, 2007, 43(1): 214-218. doi: 10.1109/TMAG.2006.887432 URL
[4]	COOPER K P, JONES H N, MEGER R A. Analysis of railgun barrel material[J]. IEEE Transactions on Magnetics, 2007, 43(1):120-125. doi: 10.1109/TMAG.2006.887654 URL
[5]	HSIEH K T. Numerical study on groove formation of rails for various materials[J]. IEEE Transactions on Magnetics, 2005, 41(1): 380-382. doi: 10.1109/TMAG.2004.839287 URL
[6]	ZIELINSKI A, WATT T, MOTES D. Disrupting armature ejecta and its effects on rail damage in solid-armature railguns[J]. IEEE Transactions on Plasma Science, 2011, 39(3): 941-946. doi: 10.1109/TPS.2010.2099241 URL
[7]	张保玉, 黄伟, 陈子明, 等. 高速滑动电接触下轨道槽蚀损伤问题研究[J]. 兵器材料科学与工程, 2015, 38(3): 140-143.
	ZHANG B Y, HUANG W, CHEN Z M, et al. Grooving damage of rails under high-velocity sliding electrical contact[J]. Ordnance Material Science and Engineering, 2015, 38(3): 140-143. (in Chinese)
[8]	张倩, 朱仁贵, 李治源, 等. 金属材料的超高速刨削研究进展[J]. 兵器材料科学与工程, 2013, 36(4):97-103.
	ZHANG Q, ZHU R G, LI Z Y, et al. Research progress in hypervelocity gouging[J]. Ordnance Material Science and Engineering, 2013, 36(4):97-103. (in Chinese)
[9]	CAMERON G, PALAZOTTO A. An evaluation of high velocity wear[J]. Wear, 2008, 265(7): 1066-1075. doi: 10.1016/j.wear.2008.02.013 URL
[10]	TARCZA K R, WELDON W F. Metal gouging at low relative sliding velocities[J]. Wear, 1997, 209(1/2): 21-30. doi: 10.1016/S0043-1648(97)00003-3 URL
[11]	吴金国. 电磁轨道炮枢轨结构动力学与超高速刨削研究[D]. 南京: 南京理工大学, 2018.
	WU J G. Study on the armature-rail structure dynamics and hypervelocity gouging of electromagnetic railgun[D]. Nanjing: Nanjing University of Science & Technology, 2018. (in Chinese)
[12]	吴金国, 林庆华, 弯港, 等. 基于物质点法的轨道炮刨削机理三维数值研究[J]. 爆炸与冲击, 2017, 37(2): 307-314.
	WU J G, LIN Q H, WAN G, et al. 3D numerical research of railgun gouging mechanism based on material point method[J]. Explosion and Shock Waves, 2017, 37(2): 307-314. (in Chinese)
[13]	杨丹, 袁伟群, 赵莹, 等. 电磁轨道发射器结构刚度系数与刨削形成[J]. 电工电能新技术, 2014, 33(3): 48-52.
	YANG D, YUAN W Q, ZHAO Y, et al. Uniformity of stiffness coefficient of electromagnetic railgun and formation of gouge[J]. Advanced Technology of Electrical Engineering and Energy, 2014, 33(3): 48-52. (in Chinese)
[14]	刘峰, 赵丽曼, 张晖辉, 等. 电磁轨道炮刨削的形成机理及仿真分析[J]. 高压物理学报, 2015, 29(3): 199-205.
	LIU F, ZHAO L M, ZHANG H H, et al. Formation mechanism and simulation analysis of railgun gouging[J]. Chinese Journal of High Pressure Physics, 2015, 29(3): 199-205. (in Chinese)
[15]	ZHU R G, ZHANG Q, LI Z Y, et al. Impact physics model and influencing factors of gouging for electromagnetic rail launcher[C]//Proceedings of the 2014 17th International Symposium on Electromagnetic Launch Technology. La Jolla, CA, US: IEEE, 2014: 1-6.
[16]	WATT T J, CLAY C E, BASSETT P M, et al. The effect of surface indentations on gouging in railguns[J]. Wear, 2014, 310(1/2): 41-50. doi: 10.1016/j.wear.2013.12.017 URL
[17]	JIN L W, ZHANG Q, LEI B, et al. Simulation and research on 3D gouging model based on Abaqus/Explicit[C]// Proceedings of the 2012 16th International Symposium on Electromagnetic Launch Technology. Beijing, China: IEEE, 2012: 1-5.
[18]	刘贵民, 杨忠须, 闫涛, 等. 电磁轨道炮导轨失效研究现状及展望[J]. 材料导报, 2015, 29(7): 63-70.
	YANG G M, YANG Z X, YAN T, et al. Current status and prospect on rail failures of electromagnetic railgun[J]. Materials Reports, 2015, 29(7): 63-70. (in Chinese)
[19]	LI S Z, CAO R G, ZHOU Y, et al. Performance analysis of electromagnetic railgun launch system based on multiple experimental data[J]. IEEE Transactions on Plasma Science, 2019, 47(1): 524-534. doi: 10.1109/TPS.2018.2883285 URL
[20]	王志恒, 万敏, 李小将. 轨道炮电枢电动力转捩形成机理与仿真分析[J]. 系统仿真学报, 2018, 30(3): 1090-1095. doi: 10.16182/j.issn1004731x.joss.201803040
	WANG Z H, WAN M, LI X J. Formation mechanism and simulation analysis of railgun armature electromagnetic transition[J]. Journal of System Simulation, 2018, 30(3): 1090-1095. (in Chinese) doi: 10.16182/j.issn1004731x.joss.201803040
[21]	STEFANI F, LEVINSON S, SATAPATHY S, et al. Electrodynamic transition in solid armature railguns[J]. IEEE Transactions on Magnetics, 2001, 37(1): 101-105. doi: 10.1109/20.911800 URL
[22]	BARBER J P, BAUER D P, JAMISON K, et al. A survey of armature transition mechanisms[J]. IEEE Transactions on Magnetics, 2003, 39(1): 47-51. doi: 10.1109/TMAG.2002.805913 URL
[23]	曹海要, 战再吉. 铜/金刚石复合材料电磁轨道烧蚀特性的实验研究[J]. 高压物理学报, 2016, 30(4): 317-322.
	CAO H Y, ZHAN Z J. Experimental study of Cu/diamond composite electromagnetic rail ablation characteristics[J]. Chinese Journal of High Pressure Physics, 2016, 30(4): 317-322. (in Chinese)
[24]	GAO X, LIU F, FENG Y, et al. Wear characteristics of rail-armature under the action of interference fit and lorentz force[J]. IEEE Transactions on Plasma Science, 2020, 48(6): 2261-2265. doi: 10.1109/TPS.27 URL
[25]	WATT T, STEFANI F. The effect of current and speed on perimeter erosion in recovered armatures[J]. IEEE Transactions on Magnetics, 2005, 41(1): 448-452. doi: 10.1109/TMAG.2004.838756 URL
[26]	DUTTA I, DELANEY L, CLEVELAND B, et al. Electric-current-induced liquid Al deposition, reaction, and flow on Cu rails at rail-armature contacts in railguns[J]. IEEE Transactions on Magnetics, 2009, 45(1): 272-277. doi: 10.1109/TMAG.2008.2008562 URL
[27]	CLIFFORD P D, II W B M. Experimental observations and analysis of armatures and rails in a small railgun[C]//Proceedings of the 2008 14th Symposium on Electromagnetic Launch Technology.Victoria, BC,Canada:IEEE, 2008: 1-6.
[28]	黄伟, 杨黎明, 史戈宁, 等. 电磁发射条件下CuCrZr合金材料轨道损伤行为研究[J]. 兵工学报, 2020, 41(5): 858-864. doi: 10.3969/j.issn.1000-1093.2020.05.004
	HUANG W, YANG L M, SHI G N, et al. Damage behavior of CuCrZr alloy rail during electromagnetic launching[J]. Acta Armamentarii, 2020, 41(5): 858-864. (in Chinese) doi: 10.3969/j.issn.1000-1093.2020.05.004
[29]	王振春, 鲍志勇, 曹海要, 等. 增强型电磁轨道炮电枢轨道接触特性研究[J]. 兵工学报, 2018, 39(3): 451-456. doi: 10.3969/j.issn.1000-1093.2018.03.005
	WANG Z C, BAO Z Y, CAO H Y, et al. Research on contact characteristics of armature and rail in augmented electromagnetic railgun[J]. Acta Armamentarii, 2018, 39(3):451-456. (in Chinese)
[30]	惠阳, 刘贵民, 闫涛, 等. 载流摩擦磨损研究现状及展望[J]. 材料导报, 2019, 33(13): 2272-2280.
	HUI Y, LIU G M, YAN T, et al. Research status and prospect of current-carrying friction and wear[J]. Material Reports, 2019, 33(13): 2272-2280. (in Chinese)
[31]	JOHNSON M, COTE P, CAMPO F, et al. Railgun erosion simulator[C]//Proceedings of the 2005 IEEE Pulsed Power Conference.Monterey, CA,US:IEEE, 2005: 245-248.
[32]	BAUER D P, JUSTON J M. Rapid testing for multishot railgun bore life[J]. IEEE Transactions on Magnetics, 1997, 33(1): 390-394. doi: 10.1109/20.560043 URL
[33]	冯登, 夏胜国, 陈立学, 等. 轨道电磁发射装置中电枢装配接触压力分布的不均匀特性[J]. 高电压技术, 2015, 41(6): 1873-1878.
	FENG D, XIA S G, CHEN L X, et al. Non-uniformity of contact pressure distribution in armature assembly for railguns[J]. High Voltage Engineering, 2015, 41(6): 1873-1878. (in Chinese)
[34]	CHEN L X, HE J J, XIA S G, et al. Some key parameters of different caliber solid-armature railgun related to linear current density[J]. IEEE Transactions on Plasma Science, 2017, 45(7): 1134-1138. doi: 10.1109/TPS.2017.2697416 URL
[35]	FENG D, HE J J, XIA S G, et al. Investigations of the armature-rail contact pressure distribution in a railgun[J]. IEEE Transactions on Plasma Science, 2015, 43(5): 1657-1662. doi: 10.1109/TPS.2015.2418215 URL
[36]	WILD B, ALOUAHABI F, SIMICIC D, et al. A comparison of c-shaped and brush armature performance[J]. IEEE Transactions on Plasma Science, 2017, 45(7): 1227-1233. doi: 10.1109/TPS.2017.2704117 URL
[37]	冯建源, 安韵竹, 赵文龙, 等. 轨道炮枢轨初始接触特性研究[J]. 兵器装备工程学报, 2019, 40(10): 54-58.
	FENG J Y, AN Y Z, ZHAO W L, et al. Research on armature and rail's initial contact characteristics of railguns[J]. Journal of Ordnance Equipment Engineering, 2019, 40(10): 54-58. (in Chinese)
[38]	范薇, 苏子舟, 范天峰, 等. C形一体电枢的结构设计及接触压力分析[J]. 兵工学报, 2019, 40(10): 1969-1976. doi: 10.3969/j.issn.1000-1093.2019.10.001
	FAN W, SU Z Z, FAN T F, et al. Geometry design and contact force analysis of c-shaped monolithic armature[J]. Acta Armamentarii, 2019, 40(10): 1969-1976. (in Chinese) doi: 10.3969/j.issn.1000-1093.2019.10.001
[39]	HSIEH K, SATAPATHY S, HSIEH M. Effects of pressure-dependent contact resistivity on contact interfacial conditions[J]. IEEE Transactions on Magnetics, 2009, 45(1): 313-318. doi: 10.1109/TMAG.2008.2008876 URL
[40]	KIM B K, HSIEH K T, BOSTICK F X. A three-dimensional finite element model for thermal effect of imperfect electric contacts[J]. IEEE Transactions on Magnetics, 1999, 35(1): 170-174. doi: 10.1109/20.738397 URL
[41]	MERRILL R, STEFANI F. A turbulent melt-lubrication model of surface wear in railgun armatures[J]. IEEE Transactions on Magnetics, 2005, 41(1): 414-419. doi: 10.1109/TMAG.2004.838755 URL
[42]	汤亮亮. 电磁发射中枢轨接触界面金属液化层特性的实验与理论研究[D]. 武汉: 华中科技大学, 2015.
	TANG L L. Experimental and theoretical study on liquid metal film characteristic of armature/rail contact interface in an electromagnetic launching[D]. Wuhan: Huazhong University of Science & Technology, 2015. (in Chinese)
[43]	WANG L. Modeling of the armature-rail interface in an electromagnetic launcher with lubricant injection[D]. Atlanta,GA,US: Georgia Institute of Technology, 2008.
[44]	RUAN J H, CHEN L X, XIONG Y, et al. A 3-d magneto-elastohydrodynamic model of liquid metal film at rail-armature interface[J]. IEEE Transactions on Plasma Science, 2020, 48(7): 2628-2634. doi: 10.1109/TPS.27 URL
[45]	李白, 鲁军勇, 谭赛, 等. 滑动电接触界面粗糙度对电枢熔化特性的影响[J]. 电工技术学报, 2018, 33(7): 1607-1615.
	LI B, LU J Y, TAN S, et al. Effect of interfacial roughness of sliding electrical contact on the melting characteristics of armature[J]. Transactions of China Electrotechnical Society, 2018, 33(7):1607-1615. (in Chinese)
[46]	阮景煇, 陈立学, 夏胜国, 等. 电磁轨道炮电流分布特性研究综述[J]. 电工技术学报, 2020, 35(21): 4423-4431.
	RUAN J H, CHEN L X, XIA S G, et al. A review of current distribution in electromagnetic railguns[J]. Transactions of China Electrotechnical Society, 2020, 35(21): 4423-4431. (in Chinese)
[47]	范薇, 苏子舟, 张涛, 等. 增强型电磁轨道炮瞬态温升时空分布[J]. 高电压技术, 2021, 47(9): 1-10.
	FAN W, SU Z Z, ZHANG T, et al. Research on spatial-temporal distribution of transient temperature rise in augmented electromagnetic railgun[J]. High Voltage Engineering, 2021, 47(9): 1-10. (in Chinese)
[48]	BAYATI M S, KESHTKAR A, KESHTKAR A. Transition study of current distribution and maximum current density in railgun by 3-d FEM-IEM[J]. IEEE Transactions on Plasma Science, 2011, 39: 13-17. doi: 10.1109/TPS.2010.2063040 URL
[49]	TANG B, LIN Q, LI B M. Research on thermal stress by current skin effect in a railgun[J]. IEEE Transactions on Plasma Science, 2017, 45(7): 1689-1694. doi: 10.1109/TPS.2017.2715219 URL
[50]	杨玉东, 王建新, 薛文. 轨道炮动态负载特性的分析与仿真[J]. 兵工学报, 2010, 31(8): 1026-1031.
	YANG Y D, WANG J X, XUE W. Simulation and analysis for dynamic load characteristic of rail-gun[J]. Acta Armamentarii, 2010, 31(8): 1026-1031. (in Chinese)
[51]	LI X, WENG C S. Three-dimensional investigation of velocity skin effect in U-shaped solid armature[J]. Progress in Natural Science, 2008, 18: 1565-1569. doi: 10.1016/j.pnsc.2008.05.024 URL
[52]	STEFANI F, MERRILL R. Experiments to measure melt-wave erosion in railgun armatures[J]. IEEE Transactions on Magnetics, 2003, 39(1): 188-192. doi: 10.1109/TMAG.2002.805955 URL
[53]	巩飞, 翁春生. 电磁轨道炮固体电枢熔化波烧蚀过程的三维数值模拟研究[J]. 高电压技术, 2014, 40(7): 2245-2250.
	GONG F, WENG C S. 3-D numerical study of melt-wave erosion in solid armature railgun[J]. High Voltage Engineering, 2014, 40(7): 2245-2250. (in Chinese)
[54]	MERRILL R, STEFANI F. Electrodynamics of the current melt-wave erosion boundary in a conducting half-space[J]. IEEE Transactions on Magnetics, 2003, 39(1): 66-71. doi: 10.1109/TMAG.2002.805907 URL
[55]	LI C X, CHEN L X, WANG Z J, et al. Influence of armature movement velocity on the magnetic field distribution and current density distribution in railgun[J]. IEEE Transactions on Plasma Science, 2020, 48(6):2308-2315. doi: 10.1109/TPS.27 URL
[56]	BARBER J P, MCNAB I R. Magnetic blow-off in armature transition[J]. IEEE Transactions on Magnetics, 2003, 39(1): 42-46. doi: 10.1109/TMAG.2002.805855 URL
[57]	MERRILL R, STEFANI F, WATT T. Magnetic repulsive forces on armature contacts[J]. IEEE Transactions on Magnetics, 2007, 43(1): 384-387. doi: 10.1109/TMAG.2006.887433 URL
[58]	徐伟东, 袁伟群, 陈允, 等. 电磁轨道发射器连续发射的滑动电接触[J]. 强激光与粒子束, 2012, 24(3): 668-672.
	XU W D, YUAN W Q, CHEN Y, et al. Sliding electrical contact performance of electromagnetic launcher system in rapid fire mode[J]. High Power Laser and Particle Beams, 2012, 24(3): 668-672. (in Chinese) doi: 10.3788/HPLPB URL
[59]	LANDEN D, SATAPATHY S, SURLS D. Measurement of high-strain-rate adiabatic strength of conductors[J]. IEEE Transactions on Magnetics, 2007, 43(1): 349-354. doi: 10.1109/TMAG.2006.887677 URL
[60]	XIA S G, CHEN L X, XIAO Z, et al. Effects of contact pressure concentrations in rail/armature surface at startup of a railgun launch[C]//Proceedings of the 2012 16th International Symposium on Electromagnetic Launch Technology.Beijing:IEEE, 2012: 1-5.
[61]	LI W Q, HU Y C, FENG J Y, et al. Research on armature structure optimization of rail gun based on multiple linear regression[J]. IEEE Transactions on Plasma Science, 2019, 47(11): 5042-5048. doi: 10.1109/TPS.27 URL
[62]	LÜ Q, XIANG H J, LEI B, et al. Flexible sliding contact between armature and rails for the practical launcher model[J]. IEEE Transactions on Plasma Science, 2017, 45(7): 1489-1495. doi: 10.1109/TPS.2017.2705806 URL
[63]	杜传通, 雷彬, 金龙文, 等. 电磁轨道炮电枢技术研究进展[J]. 火炮发射与控制学报, 2017, 38(2): 94-100.
	DU C T, LEI B, JIN L W, et al. Research progress on armature technology in electromagnetic railgun[J]. Journal of Gun Launch & Control, 2017, 38(2): 94-100. (in Chinese)
[64]	MCNAB I R, CRAWFORD M T, SATAPATHY S S, et al. IAT armature development[J]. IEEE Transactions on Plasma Science, 2011, 39(1): 442-451. doi: 10.1109/TPS.2010.2082568 URL
[65]	ZUO P, LI J, SONG X Q, et al. Characteristics of current distribution in rails and armature with different section shape rails[J]. IEEE Transactions on Plasma Science, 2013, 41(5): 1488-1492. doi: 10.1109/TPS.2013.2251907 URL
[66]	JIN L W, LEI B, ZHANG Q, et al. Electromechanical performance of rails with different cross-sectional shapes in railgun[J]. IEEE Transactions on Plasma Science, 2015, 43(5): 1220-1224. doi: 10.1109/TPS.2015.2413892 URL
[67]	WAN X B, LU J Y, LIANG D L, et al. Thermal analysis in electromagnetic rail launcher taking friction heat into account under active cooling condition[J]. IEEE Access, 2020, 8: 84720-84740. doi: 10.1109/Access.6287639 URL
[68]	SU Z Z, GUO W, ZHANG B, et al. The study of three configurations of railgun[C]//Proceedings of the 2012 16th International Symposium on Electromagnetic Launch Technology. Beijing,China: IEEE, 2012: 1-4.
[69]	NAGA PRANEETH S R, SINGH B. Influence of filleting and tapering of rails on railgun parameters[J]. IEEE Transactions on Plasma Science, 2020, 48(3): 721-726. doi: 10.1109/TPS.27 URL
[70]	NAGA PRANEETH S R, CHAUDHURI D, CHATTERJEE S, et al. A novel electromagnetic launcher configuration with improved system and barrel efficiencies[J]. IEEE Transactions on Plasma Science, 2020, 48(10): 3429-3434. doi: 10.1109/TPS.27 URL
[71]	陈立学, 何俊佳, 夏胜国, 等. 电磁轨道炮轨道电阻率和轨道高度对电流上升沿阶段电枢边沿熔蚀的影响[J]. 高电压技术, 2014, 40(4): 1071-1076.
	CHEN L X, HE J J, XIA S G, et al. Influence of rail resistivity and rail height on armature edge erosion at current ramp-up in solid armature railgun[J]. High Voltage Engineering, 2014, 40(4): 1071-1076. (in Chinese)
[72]	SIOPIS M J, NEU R W. Materials selection exercise for electromagnetic launcher rails[J]. IEEE Transactions on Magnetics, 2013, 49(8): 4831-4838. doi: 10.1109/TMAG.2013.2243460 URL
[73]	KESHTKAR A, RABIEI A, GHARIB L. Effect of armature and rails resistivity profile on rail’s electromagnetic force and armature velocity[J]. IEEE Transactions on Plasma Science, 2015, 43(5): 1541-1545. doi: 10.1109/TPS.2015.2405254 URL
[74]	CHEMERYS V T. Specifics of pulsed magnetic field penetration into electrodes of rail-type accelerator with application of the variable conductivity in the surface layers of rails at uniform acceleration of solid armature up to 2.5km/s (numerical investigation in 2-d model)[J]. IEEE Transactions on Plasma Science, 2020, 48(7): 2608-2617. doi: 10.1109/TPS.27 URL
[75]	闫涛, 刘贵民, 朱硕, 等. 电磁轨道失效与表面喷涂Mo技术研究[J]. 材料保护, 2018, 51(2): 31-35.
	YAN T, LIU G M, ZHU S, et al. Failure analysis of electromagnetic rail and study of suface spraying Mo coatings[J]. Materials Protection, 2018, 51(2): 31-35. (in Chinese)
[76]	吕庆敖, 陈建伟, 张华翔, 等. 电磁轨道炮锡合金涂层电枢/轨道温度场数值仿真[J]. 兵器装备工程学报, 2019, 40(4): 10-14.
	LÜ Q A, CHEN J W, ZHANG H X, et al. Numerical simulation of armature/ rail temperature field of tin-alloy coating for electromagnetic railgun[J]. Journal of Ordnance Equipment Engineering, 2019, 40(4): 10-14. (in Chinese)
[77]	雷彬, 杜传通, 吕庆敖, 等. 石墨烯涂层对电磁轨道炮性能影响的试验研究[J]. 高电压技术, 2019, 45(6): 1929-1935.
	LEI B, DU C T, LÜ Q A, et al. Experimental study on the influence of graphene coating on the performance of electromagnetic railgun[J]. High Voltage Engineering, 2019, 45(6): 1929-1935. (in Chinese)
[78]	SATAPATHY S, VANICEK H. Down-slope contact transition in railguns[J]. IEEE Transactions on Magnetics, 2007, 43(1): 402-407. doi: 10.1109/TMAG.2006.887593 URL