Resource-Efficient Machining of Hard Metals

Abstract:

The main requirements of carbide metal working are higher precision and high quality surface which can be fulfilled by electrical discharge machining. This procedure is accompanied with formation of heat affected zones (white layers) during the discharge process negatively. Therefore, the essential post-processing reduces the efficiency of this process and shows the importance of process energy sources (PES) with ultra short discharge in favor of a clearly differentiated cutting volume. By means of simulations of crater geometry and channel expansion the influence of discharge rise time is defined as determining factor for the cut volume and formation of white layers. The technological section presents two different approaches of realizing ultra-short pulses.

References

[1] G. Wollenberg, H-P. Schulze, T. Pape, M. Läuter, Moderne Generatortechnik für die funkenerosive Bearbeitung. 4. Aachener Fachtagung Funkenerosive Bearbeitung,. 1999, p.9/1-26.

DOI: 10.1007/978-3-663-02467-5_2

[2] G. Wollenberg, H-P. Schulze, T. Pape, M. Läuter, Process energy supply for unconventional machining, Proceedings of the 13th International Symposium for Electromachining ISEM XIII, Bilbao, SPAIN, (ISBN: 932064-0-7) Vol. I, pp.283-294.

[3] H. -P. Schulze, M. Läuter, W. Rehbein, K. Mecke. Channel spreading during the spark discharge for selected conditions and working fluids. Proceedings of the 2003 Annual Report Conference on Electrical Insulation and Dielectric Phenomena. Albuquerque, New Mexico, USA, 2003, pp.297-300.

DOI: 10.1109/ceidp.2003.1254852

[4] H. -P. Schulze, H. Juhr, Influence of needle Pulse shifting on the basis pulse for. Proceedings of the 16th International Symposium for Electromachining ISEM XVI, Harmony, Shanghai, 2010, pp.249-253.

[5] H. Juhr, H. -P. Schulze, G. Wollenberg, K. Künanz, Improved cemented carbid properties after wire-EDM by pulse shaping, Journal of materials technology. Amsterdam, 2004, pp.178-183.

DOI: 10.1016/j.jmatprotec.2004.02.037

[6] S. Kwon, M.Y. Yang, The benefits of using instantaneous energy to monitor the transient state of the wire EDM process. International Journal for Advanced Manufacturing Technology, 27, February 2006, pp.930-938.

DOI: 10.1007/s00170-004-2252-y

[7] M. Timm, elektronische Stromquellen für funkenerosive Schneiden von elektrisch schlecht leitfähigen Werkstoffen. Magdeburg : Otto-von-Guericke-Universität Magdeburg, (1996).

[8] V. Schulze, C. Ruhs, C. Kühlewein und M. Deuchert, "Simulationsgestützte Entwicklung von Mikrofräswerkzeugen, MM Maschinenmarkt, Bd. 32, pp.14-18, 8 (2009).

[9] V. Schulze, J. Michna, R. Pabst und T. Hauer. Geometrieoptimierung von Mikrofräsern, Mikroproduktion, 2009, pp.40-44.