Transactions of the Korean Society of Mechanical Engineers A (대한기계학회논문집A)

The Korean Society of Mechanical Engineers (대한기계학회)
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Influence of Electrical Conductivity of Dielectric on Machinability of W-EDM

방전액의 전도율이 와이어방전가공성에 미치는 영향

  • Published : 2002.02.01
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Abstract

In wire-electrical discharge machining (W-EDM), the dielectric plays an important role as the working fluid. It affects the material removal rate and the properties of the machined surface. This paper deals with the effects of the electrical conductivity of dielectric and cobalt percentage of sintered carbides on the machining characteristics and the machined surface integrities with deionized water as dielectric. A series of experiments have been performed on sintered carbides having different cobalt contents. Experimental results show that a higher cobalt content of WC decreases the metal removal rate and worsens the surface quality. Lower electrical conductivity of the dielectric results in a higher metal removal rate as the gap between wire electrode and workpiece reduced. Especially, the surface integrities of rough-cut workpiece, wire electrode, and debris were analyzed also through scanning electron microscopy(SEM) and surface roughness tester. By energy dispersive spectrometry(EDS), it is confirmed that micro cracks and some of electrode material are found on the workpiece surface.

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References

  1. 강상훈, 박원조, 배성한, 1993, 'CAD/CAM 와이어 방전가공의 가공확대 여유에 관한 연구,' 대한기계학회논문집, Vo. 17, No. 2, pp. 380-384
  2. Dauw, D. F. and Albert, L., 1992, 'About the Evolution of Wire Tool Performance in Wire EDM,' Annals of the CIRP, Vol. 41, No. 1, pp. 221-225 https://doi.org/10.1016/S0007-8506(07)61190-1
  3. Kunieda, M. and Yanatori, K., 1996, 'Study on Debris Movement in EDM Gap,' Int'l J. of Electrical Machining(IJEM), No. 2, pp. 43-49
  4. Luo, Y. F., 1997, 'The Dependence of Interface Discharge Transitivity upon the Gap Debris in Precision Electrodischarge Machining,' J. of Material Processing Technology, Vol. 68, pp. 121-131 https://doi.org/10.1016/S0924-0136(96)00019-2
  5. Charmilles Technologies Co., 1993, Operating Manual
  6. 김창호, Kruth J. P., 1999, '초경합금의 와이어 방전가공 가공성 및 표면특성,' 한국정밀공학회지, 제16권 제8호, pp. 100-105
  7. Cornelissen, H., Snoeys, R. and Kruth, J. P., 1977, 'Investigation on the Optimal Machining Conditions for Electro-Discharge Machining of Cemented Carbides,' 5th North American Metalworking Research Conference(NAMRC-V), pp. 258-263
  8. Heuvelman, C. J., 1980, 'Summary Reports on the Cooperative Research on Spark- Erosion Machining of Cemented Carbides (Die-Sinking),' Annals of the CIRP, Vol. 29, No. 2, pp. 541-544 https://doi.org/10.1016/S0007-8506(16)30149-4
  9. 齋藤長男, 小林和彦, 仙化谷 英次, 1992, 'ウイヤカツト 放電加工技術,' 目刊工業新聞社, pp. 48-57
  10. Schmuacher, B. M. and Agie, A.G., 1990, 'About the Role of Debris in the Gap During Electrical Discharge Machining,' Annals of the CIRP, Vol. 39, No.1, pp. 197-199 https://doi.org/10.1016/S0007-8506(07)61034-8
  11. Dunnebacke, G., 1992, 'High Performance Electrical Discharge Machining using Water-based Dielectric,' Proc. of the 10th Int'l Symp. for Electromachining(ISEM-X), pp. 161-169
  12. Gadalla, A. M. and Tsai, W., 1989, 'Electrical Discharge Machining of Tungsten Carbide-Cobalt Composites,' J. of American Ceramic society, Vol. 72, No. 8, pp. 1396-1401 https://doi.org/10.1111/j.1151-2916.1989.tb07660.x
  13. 김민건, 지정근, 태원필, 1993, '고경질재료 방전가공부의 피로파괴 특성,' 대한기계학회논문집, Vol. 17, No. 1, pp. 21-26