喷雾电火花加工的实验研究
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摘要
喷雾电火花加工是一种采用具有一定压力的水雾作为电介质的电火花加工新方法。通过使用空气和自来水形成水雾,用作电火花加工用的绝缘介质,具有无污染、低成本、无需工作液循环系统的特点。本文分析了雾介质的击穿特性,并通过分析喷雾电火花加工的机理得出了与液体介质相比在雾介质中的放电通道扩展快,通道的能量密度较低,电蚀坑大而浅的结论;深入讨论了电极材料的抛出及极间消电离过程。
通过实验研究了电极极性、峰值电流、脉冲宽度、脉冲间隔、间隙伺服参考电压、工具电极壁厚等参数对喷雾电火花加工的材料去除率及相对电极损耗率的影响规律。通过与煤油基工作液中的常规电火花加工的对比实验发现相同加工条件下喷雾电火花加工脉冲放电击穿延时较短,维持电压比煤油基工作液中的低2V左右,加工表面质量较好;相同条件下喷雾电火花加工的相对电极损耗低于煤油基工作液中的结果。但目前加工中仍存在短路率和空载率较高的问题,致使其加工效率低于煤油基工作液中的常规电火花加工。
This thesis presents a new electrical discharge machining (EDM) method -- Jetted-mist EDM, by using jetted mist as its dielectric working medium instead of oil based working fluid. The jetted mist can be generated mainly with the tap water and compressed air. In contrast with conventional EDM in dielectric fluid, Jetted-mist EDM generates no waste, and needs not the filtration and circulation system, therefore it is more environmentally friendly and more economically beneficial.
The breakdown characteristics of the jetted mist is discussed. Based on analysis of the mechanism of the jetted-mist EDM, some comparisons between mist and oil based medium are made. The results indicate that the expansion of discharge channel in mist is faster than that in oil based dielectric; The energy density of the discharge channel in the mist is lower; And the craters produced in the mist are larger and shallower. The deionization of the discharge channel and the blowing of electrode material in the mist are also studied.
The relationship between machining performances (such as material
通过实验研究了电极极性、峰值电流、脉冲宽度、脉冲间隔、间隙伺服参考电压、工具电极壁厚等参数对喷雾电火花加工的材料去除率及相对电极损耗率的影响规律。通过与煤油基工作液中的常规电火花加工的对比实验发现相同加工条件下喷雾电火花加工脉冲放电击穿延时较短,维持电压比煤油基工作液中的低2V左右,加工表面质量较好;相同条件下喷雾电火花加工的相对电极损耗低于煤油基工作液中的结果。但目前加工中仍存在短路率和空载率较高的问题,致使其加工效率低于煤油基工作液中的常规电火花加工。
This thesis presents a new electrical discharge machining (EDM) method -- Jetted-mist EDM, by using jetted mist as its dielectric working medium instead of oil based working fluid. The jetted mist can be generated mainly with the tap water and compressed air. In contrast with conventional EDM in dielectric fluid, Jetted-mist EDM generates no waste, and needs not the filtration and circulation system, therefore it is more environmentally friendly and more economically beneficial.
The breakdown characteristics of the jetted mist is discussed. Based on analysis of the mechanism of the jetted-mist EDM, some comparisons between mist and oil based medium are made. The results indicate that the expansion of discharge channel in mist is faster than that in oil based dielectric; The energy density of the discharge channel in the mist is lower; And the craters produced in the mist are larger and shallower. The deionization of the discharge channel and the blowing of electrode material in the mist are also studied.
The relationship between machining performances (such as material
引文
[1] 赵万生. 先进电火花加工技术. 北京: 国防工业出版社, 2003
[2] D.F.Dauw, B.M.Schumacher. Milestones of worldwide EDM research activities. In: Proceedings of the Ninth International Symposium on Electromachining (ISEM9), Nagoya, Japan, 1989: 250–254
[3] C.Frei. New methods of conditioning the dielectric liquid in EDM. In: Proceedings of the 10th International Symposium on Electromachining (ISEM X), Magdeburg, Germany, 1992: 84-87
[4] 高上品. 电火花成形加工工作液的物理化学性质. 电加工与模具, 2005(5): 38-40
[5] D.Sc. G.N.Levy, Dipl.lng. B.Sager. 放电加工用碳氢化合物工作液的正确选择及综 合比较. 国际电加工新技术 ISEM-9 论文选编. 北京: 北京科学技术出版, 1991: 17-23
[6] 毛利尚武, 斋藤长男, 人竹宏定等. 大面积仕上放电加工研究. 精密工学会志, 1987, 53(1): 124-130
[7] 斋藤长男, 毛利尚武. 大面积放电加工表面粗糙度的研究. 精密工学会志, 1991, v25(49):47-60
[8] 李岐新. 电火花超精精面加工新工艺和新装备. Mechatronics, 1998(6): 39-41
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[10] 林義生. 粉末混入放電加工機と精密加工. 型技術, 1997, 12(8): 92-93
[11] 林義生. 高速光沢放電加工機. 型技術, 1997,12(3):67-71
[12] 笠﨑栄. 放電加工にょる高能率仕上加工「HQSF」.機械と工具, 1999(3):37-40
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[14] 索来春, 孟庆国, 郭永丰等. 混粉大面积电火花加工机理的分析. 制造技术与机 床, 1998(7):24-26
[15] Han-Ming Chow, Biing-Hwa, Fuang-Yuang,etc. Study of added powder in Kerosene for the micro-slit machining of titanium alloy using electro-discharge machining. Journal of Materials Processing Technology, 2000, v101(4):95-103
[16] 何广敏. 镜面电火花加工工艺及超精规准脉冲电源的研究. 哈尔滨工业大学工学 博士论文, 1999:5-8
[17] 全燕明. EDM 煤油工作液中添加剂的作用机理探讨. 电加工, 1994(3):11-16
[18]Quan Yanming, Liu Youhe. Powder suspension dielectric fluid for EDM. Journal ofMaterials Processing Technology, 1995, v(52): 44-54
[19] 王克锡. 大面积镜面电火花加工法. 金属述成型工艺, 1996(5): 24-30
[20] 朱玲珑, 扬连文, 赵福令. 混粉电火花加工工艺初探. 电加工, 1999(5): 24-27
[21] M.Kunieda, S.Furuoya. Improvement of EDM Efficiency by Supplying Oxygen Gas into Gap.Annals of the CIRP, 1991, v40(1): 215-218
[22] 何广敏, 赵万生,郭永丰.混气电火花镜面加工的研究. 制造技术与机床, 2000(3):43-44
[23] Fábio N. Le?o, Ian R. Pashby.A review on the use of environmentally-friendly dielectric fluids in electrical discharge machining. Journal of Materials Processing Technology, 2004, v(149):341-346
[24] A. Erden, D.Temel. Investigation on the use of water as a dielectric liquid in electric discharge machining. In: Proceedings of the 22nd Machine Tool Design and Research Conference, Manchester, 1981: 437–440
[25] S.L. Chen, B.H. Yan, F.Y. Huang. Influence of kerosene and distilled water as dielectrics on the electric discharge machining characteristics of Ti–6Al–4V. J. Mater. Process Tech, 1999, v87:107–111
[26] W. K?nig, L. J?rres. Aqueous solutions of organic compounds as dielectrics for EDM sinking. Ann. CIRP, 1987,v36:105–109
[27] T. Masuzawa. Machining characteristics of EDM using water as dielectric fluid. In: Proceedings of the 22nd Machine Tool Design and Research Conference, Manchester, 1981:441–447
[28] T. Masuzawa, K. Tanaka, Y. Nakamura. Water-based dielectric solution for EDM. Ann. CIRP,1983, v32:119–122
[29] W. K?nig, F. Klocke, M. Sparrer. EDM-sinking using water-based dielectrics and electropolishing——a new manufacturing sequence in tool-making. In: Proceedings of the 11th International Symposium on Electromachining (ISEM XI), Lausanne, Switzerland, 1995:225–234
[30] G. Dünnebacke. High performance electrical discharge machining using a water-based dielectric. In: Proceedings of the 10th International Symposium for Electromachining (ISEM X), Magdeburg,Germany, 1992:170–182
[31] R. Dewes, D. Aspinwall, J. Burrows, M. Paul, F. El-Menshawy. High speed machining-multi-function/hybrid systems. In: Proceedings of the Fourth International Conference on Industrial Tooling, Southampton, UK, 2001:91–100
[32] T. Karasawa, M. Kunieda. EDM capability with poured dielectric fluids without a tub. Bull. Jpn. Soc. Precision Eng, 1990, v24:217–218
[33] B.W. Pillans, M.H. Evensen, H.F. Taylor, P.T. Eubank. Fiber optic diagnostic techniques applied to electrical discharge machining sparks. J. Appl. Phys, 2002, v91:1780–1786.
[34] J.A. Mc Geough. Advanced Methods of Machining. Chapman & Hall, London, 1988 (ISBN 0412319705)
[35]J.P. Kruth, L. Stevens, L. Froyen, B. Lauwers, K.U. Leuven. Study of the white layer of a surface machined by die-sinking electrodischarge machining. Ann. CIRP, 1995, v44: 169–172
[36] R. Kranz, F. Wendl, K.-D. Wupper. Influence of EDM conditions on the toughness of tool steels. Thyssen Edelstahl Technische Berichte, 1990:100–105
[37] I. Ogata, Y. Mukoyama. Carburizing and decarburizing phenomena in EDM surface. Int. J. Jpn. Soc. Precision Eng, 1993, v27:197–202
[38] Kunieda, M., Yoshida, M.. Electrical discharge machining in gas. Annals of the CIRP, 1997,v46:143-146
[39] Kunieda, M., Y. Miyoshi, T.Takaya, etc. High Speed 3D Milling by Dry EDM. Annals of the CIRP, 2003, v52:147-150.
[40] ZhanBo Yu, Takahashi Jun, Kunieda Masanori. Dry Electrical Discharge Machining of cemented Carbide. Journal of Materials Processing Technology, 2003, v149:353-357
[41] Kunieda.M, T.Takaya, Shintaro Nakano, etc. Improvement of Dry EDM characteristics using piezoelectric actuator. Journal of Materials Processing Technology, 2004, v149(1):353-357
[42] 王彤,陈玉全,国枝正典. 气中电火花线切割加工技术研究. 机械工程学报,2003, v39(8):76-80
[43] Wang, T., Kunieda, M. Dry WEDM for Finish Cut. Key Engineering Materials, 2003, v562:259-260
[44] Wang,T, Kunieda,M. Study on dry WEDMed surface layer of cold tool steel SKD11. International journal of electrical machining, 2002(7):3-4
[45] Q.H.Zhang, J.H.Zhang, J.X.Deng, etc. Ultrasonic vibration electrical discharge machining in gas. Journal of materials processing technology, 2002:123-138
[46] 张建华,张勤河,孟艳华等. 超声振动辅助气中放电加工的研究. 加下与模具, 2004(4):13-16
[47] 徐明刚,张建华,张勤河. 超声振动辅助气体介质电火花加工放电通道的研究.电加 工与模具, 2005(4): 16-18
[48] 李立青,王振龙,赵万生. 气中放电加工机理分析. 哈尔滨工业大学学报, 2004, v36(3): 359-362
[49] 李立青,赵万生,狄士春等.气体介质中电火花铣削加工工艺实验研究. 南京理工 大学学报, 2006, v30(1): 12-16
[50] T.Tanimura, K.Isuzagawa, I.Fujita, etc. 雾状工作介质中进行放电加工的进展. 国 际电加工新技术 ISEM-9 论文选编. 北京: 北京科学技术出版社, 1991: 197-203
[51] 顾琳, 赵万生, 张志华等. 喷雾电火花铣削加工及其机理的分析. 电加工与模具, 2006(2): 1-4
[52] 李明辉. 电火花加工理论基础. 北京:国防工业出版社,1989
[53] 陈季丹, 刘子玉. 电介质物理学. 北京:机械工业出版社,1982
[54] 房玉东, 朱小勇, 刘江虹等. 细水雾灭火技术在电气环境的研究与进展. 中国工 程科学, 2007, v8(7):89-93
[55] 房玉东,刘江虹,廖光煊等. 含 MC 添加剂超细水雾作用下电气设备击穿强度变 化规律的实验研究. 科学通报, 2005, v50(18):2032-2036
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[58] 黄鑫,刘江虹,姚光煊等. 气泡雾化细水雾灭火有效性实验研究. 火灾科学, 2003, v12(3):160-164
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[2] D.F.Dauw, B.M.Schumacher. Milestones of worldwide EDM research activities. In: Proceedings of the Ninth International Symposium on Electromachining (ISEM9), Nagoya, Japan, 1989: 250–254
[3] C.Frei. New methods of conditioning the dielectric liquid in EDM. In: Proceedings of the 10th International Symposium on Electromachining (ISEM X), Magdeburg, Germany, 1992: 84-87
[4] 高上品. 电火花成形加工工作液的物理化学性质. 电加工与模具, 2005(5): 38-40
[5] D.Sc. G.N.Levy, Dipl.lng. B.Sager. 放电加工用碳氢化合物工作液的正确选择及综 合比较. 国际电加工新技术 ISEM-9 论文选编. 北京: 北京科学技术出版, 1991: 17-23
[6] 毛利尚武, 斋藤长男, 人竹宏定等. 大面积仕上放电加工研究. 精密工学会志, 1987, 53(1): 124-130
[7] 斋藤长男, 毛利尚武. 大面积放电加工表面粗糙度的研究. 精密工学会志, 1991, v25(49):47-60
[8] 李岐新. 电火花超精精面加工新工艺和新装备. Mechatronics, 1998(6): 39-41
[9] 毛利尙武. 放電加工技術. 機械と工具, 1999(1): 32-37
[10] 林義生. 粉末混入放電加工機と精密加工. 型技術, 1997, 12(8): 92-93
[11] 林義生. 高速光沢放電加工機. 型技術, 1997,12(3):67-71
[12] 笠﨑栄. 放電加工にょる高能率仕上加工「HQSF」.機械と工具, 1999(3):37-40
[13] 孟庆国, 赵万生, 李文卓. 粉末特性对混粉电火花镜面加工的影响. 电加工与模 具, 2000(4): 13-16
[14] 索来春, 孟庆国, 郭永丰等. 混粉大面积电火花加工机理的分析. 制造技术与机 床, 1998(7):24-26
[15] Han-Ming Chow, Biing-Hwa, Fuang-Yuang,etc. Study of added powder in Kerosene for the micro-slit machining of titanium alloy using electro-discharge machining. Journal of Materials Processing Technology, 2000, v101(4):95-103
[16] 何广敏. 镜面电火花加工工艺及超精规准脉冲电源的研究. 哈尔滨工业大学工学 博士论文, 1999:5-8
[17] 全燕明. EDM 煤油工作液中添加剂的作用机理探讨. 电加工, 1994(3):11-16
[18]Quan Yanming, Liu Youhe. Powder suspension dielectric fluid for EDM. Journal ofMaterials Processing Technology, 1995, v(52): 44-54
[19] 王克锡. 大面积镜面电火花加工法. 金属述成型工艺, 1996(5): 24-30
[20] 朱玲珑, 扬连文, 赵福令. 混粉电火花加工工艺初探. 电加工, 1999(5): 24-27
[21] M.Kunieda, S.Furuoya. Improvement of EDM Efficiency by Supplying Oxygen Gas into Gap.Annals of the CIRP, 1991, v40(1): 215-218
[22] 何广敏, 赵万生,郭永丰.混气电火花镜面加工的研究. 制造技术与机床, 2000(3):43-44
[23] Fábio N. Le?o, Ian R. Pashby.A review on the use of environmentally-friendly dielectric fluids in electrical discharge machining. Journal of Materials Processing Technology, 2004, v(149):341-346
[24] A. Erden, D.Temel. Investigation on the use of water as a dielectric liquid in electric discharge machining. In: Proceedings of the 22nd Machine Tool Design and Research Conference, Manchester, 1981: 437–440
[25] S.L. Chen, B.H. Yan, F.Y. Huang. Influence of kerosene and distilled water as dielectrics on the electric discharge machining characteristics of Ti–6Al–4V. J. Mater. Process Tech, 1999, v87:107–111
[26] W. K?nig, L. J?rres. Aqueous solutions of organic compounds as dielectrics for EDM sinking. Ann. CIRP, 1987,v36:105–109
[27] T. Masuzawa. Machining characteristics of EDM using water as dielectric fluid. In: Proceedings of the 22nd Machine Tool Design and Research Conference, Manchester, 1981:441–447
[28] T. Masuzawa, K. Tanaka, Y. Nakamura. Water-based dielectric solution for EDM. Ann. CIRP,1983, v32:119–122
[29] W. K?nig, F. Klocke, M. Sparrer. EDM-sinking using water-based dielectrics and electropolishing——a new manufacturing sequence in tool-making. In: Proceedings of the 11th International Symposium on Electromachining (ISEM XI), Lausanne, Switzerland, 1995:225–234
[30] G. Dünnebacke. High performance electrical discharge machining using a water-based dielectric. In: Proceedings of the 10th International Symposium for Electromachining (ISEM X), Magdeburg,Germany, 1992:170–182
[31] R. Dewes, D. Aspinwall, J. Burrows, M. Paul, F. El-Menshawy. High speed machining-multi-function/hybrid systems. In: Proceedings of the Fourth International Conference on Industrial Tooling, Southampton, UK, 2001:91–100
[32] T. Karasawa, M. Kunieda. EDM capability with poured dielectric fluids without a tub. Bull. Jpn. Soc. Precision Eng, 1990, v24:217–218
[33] B.W. Pillans, M.H. Evensen, H.F. Taylor, P.T. Eubank. Fiber optic diagnostic techniques applied to electrical discharge machining sparks. J. Appl. Phys, 2002, v91:1780–1786.
[34] J.A. Mc Geough. Advanced Methods of Machining. Chapman & Hall, London, 1988 (ISBN 0412319705)
[35]J.P. Kruth, L. Stevens, L. Froyen, B. Lauwers, K.U. Leuven. Study of the white layer of a surface machined by die-sinking electrodischarge machining. Ann. CIRP, 1995, v44: 169–172
[36] R. Kranz, F. Wendl, K.-D. Wupper. Influence of EDM conditions on the toughness of tool steels. Thyssen Edelstahl Technische Berichte, 1990:100–105
[37] I. Ogata, Y. Mukoyama. Carburizing and decarburizing phenomena in EDM surface. Int. J. Jpn. Soc. Precision Eng, 1993, v27:197–202
[38] Kunieda, M., Yoshida, M.. Electrical discharge machining in gas. Annals of the CIRP, 1997,v46:143-146
[39] Kunieda, M., Y. Miyoshi, T.Takaya, etc. High Speed 3D Milling by Dry EDM. Annals of the CIRP, 2003, v52:147-150.
[40] ZhanBo Yu, Takahashi Jun, Kunieda Masanori. Dry Electrical Discharge Machining of cemented Carbide. Journal of Materials Processing Technology, 2003, v149:353-357
[41] Kunieda.M, T.Takaya, Shintaro Nakano, etc. Improvement of Dry EDM characteristics using piezoelectric actuator. Journal of Materials Processing Technology, 2004, v149(1):353-357
[42] 王彤,陈玉全,国枝正典. 气中电火花线切割加工技术研究. 机械工程学报,2003, v39(8):76-80
[43] Wang, T., Kunieda, M. Dry WEDM for Finish Cut. Key Engineering Materials, 2003, v562:259-260
[44] Wang,T, Kunieda,M. Study on dry WEDMed surface layer of cold tool steel SKD11. International journal of electrical machining, 2002(7):3-4
[45] Q.H.Zhang, J.H.Zhang, J.X.Deng, etc. Ultrasonic vibration electrical discharge machining in gas. Journal of materials processing technology, 2002:123-138
[46] 张建华,张勤河,孟艳华等. 超声振动辅助气中放电加工的研究. 加下与模具, 2004(4):13-16
[47] 徐明刚,张建华,张勤河. 超声振动辅助气体介质电火花加工放电通道的研究.电加 工与模具, 2005(4): 16-18
[48] 李立青,王振龙,赵万生. 气中放电加工机理分析. 哈尔滨工业大学学报, 2004, v36(3): 359-362
[49] 李立青,赵万生,狄士春等.气体介质中电火花铣削加工工艺实验研究. 南京理工 大学学报, 2006, v30(1): 12-16
[50] T.Tanimura, K.Isuzagawa, I.Fujita, etc. 雾状工作介质中进行放电加工的进展. 国 际电加工新技术 ISEM-9 论文选编. 北京: 北京科学技术出版社, 1991: 197-203
[51] 顾琳, 赵万生, 张志华等. 喷雾电火花铣削加工及其机理的分析. 电加工与模具, 2006(2): 1-4
[52] 李明辉. 电火花加工理论基础. 北京:国防工业出版社,1989
[53] 陈季丹, 刘子玉. 电介质物理学. 北京:机械工业出版社,1982
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