Fabrication of Microstructures on RB-SiC by Ultrasonic Cavitation Assisted Micro-Electrical Discharge Machining
Pay Jun Liew*, ***, Keita Shimada*, Masayoshi Mizutani*,
Jiwang Yan**, and Tsunemoto Kuriyagawa*
*Department of Mechanical Systems and Design, Tohoku University, 6-6-01 Aoba, Aramaki, Aoba-ku, Sendai 980-8579, Japan
**Department of Mechanical Engineering, Faculty of Science and Technology, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama 223-8522, Japan
***Manufacturing Process Department, Faculty of Manufacturing Engineering, Universiti Teknikal Malaysia Melaka, Hang Tuah Jaya, 76100 Durian Tunggal, Melaka, Malaysia
Ultrasonic cavitation assisted micro-electrical discharge machining was used to fabricate microstructures on reaction-bonded silicon carbide. To aid the removal of debris from the machining gap and to obtain a good surface finish, carbon nanofibers were added into the dielectric fluid. The suspension of carbon nanofibers in the dielectric fluid and the cavitation bubble effect induced by the vibration of the dielectric fluid proved to be effective in reducing the deposition of tool material on the workpiece surface. The tool material deposition rate was found to be significantly affected by the vibration amplitude and the distance between the oscillator and the workpiece. With a hemispherical electrode and inclined workpiece, high accuracy micro-dimples could be obtained within a short time. A nanometer-level surface finish was successfully obtained on a hard-brittle RB-SiCmoldmaterial.
-  J. C. Hung, J. K. Lin, B. H. Yan, H. S. Liu, and P. H. Ho, “Using a helical micro-tool in micro-EDM combined with ultrasonic vibration for micro-hole machining,” J. of Micromechanics and Microengineering, Vol.16, pp. 2705-2713, 2006.
-  M. H. Wu and G. M. Whitesides, “Fabrication of two-dimensional arrays of microlenses and their applications in photolithography,” J. of Micromechanics and Microengineering, Vol.12, pp. 747-758, 2002.
-  C. C. Chiu and Y. C. Lee, “Fabricating of aspheric micro-lens array by excimer laser micromachining,” Optics and Lasers in Engineering, Vol.49, pp. 1232-1237, 2011.
-  M. B. Stern and T. R. Jay, “Dry etching for coherent refractive microlens arrays,” Optical Engineering, Vol.33, No.11, pp. 3547-3551, 1994.
-  C. T. Pan and C. H. Su, “Fabrication of gapless triangular microlens array,” Sensors and Actuators A, Vol.134, pp. 631-640, 2007.
-  I. S. Kang, J. S. Kim, M. C. Kang, and K. Y. Lee, “Tool condition and machined surface monitoring for micro-lens array fabrication in mechanical machining,” J. of Materials Processing Technology, Vol.201, pp. 585-589, 2008.
-  H. Weule, V. Huntrup, and H. Tritschler, “Micro-cutting of steel to meet new requirements in miniaturization,” CIRP Annals-Manufacturing Technology, Vol.50, pp. 61-64, 2001.
-  Z. Zhang, H. Peng, and J. Yan, “Micro-cutting characteristics of EDM fabricated high-precision polycrystalline diamond tools,” Int. J. of Machine Tools and Manufacture, Vol.65, pp. 99-106, 2013.
-  D. Reynaerts, W.Meeusen, and H. V. Brussel, “Machining of threedimensional microstructures in silicon by electro-discharge machining,” Sensors and Actuators A, Vol.67, pp. 159-165, 1998.
-  K. H. Ho and S. T. Newman, “State of the art electrical discharge machining (EDM),” Int J. of Machine Tools and Manufacture, Vol.43, pp. 1287-1300, 2003.
-  P. J. Liew, J. Yan, and T. Kuriyagawa, “Experimental investigation on material migration phenomena in micro-EDM of reactionbonded silicon carbide,” Applied Surface Science, Vol.276, pp. 731-743, 2013.
-  R. Garn, A. Schubert, and H. Zeidler, “Analysis of the effect of vibrations on the micro-EDM process at the workpiece surface,” Precision Engineering, Vol.35, pp. 364-368, 2011.
-  K. T. Hoang and S. H. Yang, “A study on the effect of different vibration-assisted methods in micro-WEDM,” J. of Materials Processing Technology, Vol.213, pp. 1616-1622, 2013.
-  T. Ichikawa and W. Natsu, “Realization of micro-EDM under ultrasmall discharge energy by applying ultrasonic vibration to machining fluid,” Procedia CIRP, Vol.6, pp. 326-331, 2013.
-  P. J. Liew, J. Yan, and T. Kuriyagawa, “Fabrication of micro deep holes on reaction-bonded SiC by ultrasonic cavitation assisted micro EDM,” Int. J. of Machine Tools and Manufacture. (In press)
-  P. J. Liew, J. Yan, and T. Kuriyagawa, “Carbon nanofiber assisted micro electro discharge machining of reaction-bonded silicon carbide,” J. of Materials Processing Technology, Vol.213, Issue 7, pp. 1076-1087, 2013.
-  Technical data provided by the manufacture of the workpiece material.
-  N. Ravi and H. Huang, “Fabrication of symmetrical section microfeatures using the electro-discharge machining block electrode method,” J. of Micromechanics and Microengineering, Vol.12, pp. 905-910, 2002.
-  A. Perveen, Y. S. Wong, and M. Rahman, “Fabrication of different geometry cutting tools and their effect on the vertical microgrinding of BK7 glass,” Int. J. of Advanced Manufacturing Technology, Vol.61, pp. 101-115, 2012.
-  B. Ekmekci and A. Sayar, “Debris and consequences in micro electric discharge machining of micro-holes,” Int. J. of Machine Tools and Manufacture, Vol.65, pp. 58-67, 2013.
-  S. Clijsters, K. Liu, D. Reynaerts, and B. Lauwers, “EDM technology and strategy development for the manufacturing of complex parts in SiSiC,” J. of Materials Processing Technology, Vol.210, pp. 631-641, 2010.
-  B. Vyas and C. M. Preece, “Stress produced in a solid by cavitation,” J. of Applied Physics, Vol.47, No.12, pp. 5133-5138, 1976.