Journal of The Japan Society of Electrical Machining Engineers
Online ISSN : 1881-0888
Print ISSN : 0387-754X
ISSN-L : 0387-754X
Volume 37, Issue 84
Displaying 1-6 of 6 articles from this issue
  • Yuzo MORI, Kikuji HIROSE, Hidekazu GOTO
    2003 Volume 37 Issue 84 Pages 1-8
    Published: March 25, 2003
    Released on J-STAGE: March 12, 2010
    JOURNAL FREE ACCESS
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  • Toshiki Kobayashi, Masanori Kunieda
    2003 Volume 37 Issue 84 Pages 9-16
    Published: March 25, 2003
    Released on J-STAGE: March 12, 2010
    JOURNAL FREE ACCESS
    This paper describes a newly developed hybrid EDM system which is composed of the multispark EDM system and conventional EDM system. Multispark EDM is characterized by higher removal rates and lower energy consumption compared with conventional EDM. However, it was difficult to obtain a continuously stable state with the multispark mode. This hybrid EDM system therefore switches the operation mode from the multispark mode to the conventional mode when the process becomes unstable. Then, if the gap state satisfies the condition under which the multispark mode can work stably, the mode is switched back to the multispark mode. From experiments, it was confirmed that the hybrid system developed works very well even under the machining conditions which make the process unstable with the multispark mode.
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  • EDM Machinability and 3-D Contouring EDM by Wire Frame Electrode
    Hisashi MINAMI, Kiyonori MASUI, Hidekazu TSUKAHARA, Tatsuya YAMAMOTO, ...
    2003 Volume 37 Issue 84 Pages 17-22
    Published: March 25, 2003
    Released on J-STAGE: March 12, 2010
    JOURNAL FREE ACCESS
    High-strength Zn alloy (ZAPREC) was developed for improving the mechanical properties of commercial Zn alloy (ZAS). This paper describes the EDM machinability of Zn alloy for die making. The experimental results were compared with die steel (SKD11) machinability. As a result, newly developed Zn alloy gives high-speed EDM with lower electrode wear ratio under the finishing conditions. Therefore, Zn alloy with these excellent EDM machinabilities enables effective die making using three-dimensional contouring EDM by wire frame electrode.
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  • Dispersion of Insulating Powder into Deposit
    Katsushi FURUTANI, Hirotaka SUNADA
    2003 Volume 37 Issue 84 Pages 23-30
    Published: March 25, 2003
    Released on J-STAGE: March 12, 2010
    JOURNAL FREE ACCESS
    This paper deals with a fabrication method of an abrasive layer by electrical discharge machining (EDM). A grinding wheel should be frequently dressed and as a result its total life becomes shorter. When the total life of the grinding wheel has ended, the grinding wheel is disposed of even if its core is still usable. To extend the total life of the grinding wheel by recycling, a fabrication process of an abrasive layer by EDM is proposed. The layer deposited by EDM with a green compact electrode is porous due to the electrical conditions. The green compact electrode was made by compressing a mixture of WC, Co and an abrasive, which is generally an insulating material. The layer produced with the dispersed abrasive powders with a size of 20-100μm could be deposited on a plate. The grain size and the thermal conductivity mainly affect the layer properties. Each grain volume percentage was evaluated with a partial section analyzed by energy dispersive X-ray spectroscopy. The volume percentages of #150 and #400 SiC grains were 6% and 10%, respectively, when the volume ratio of the SiC grains in each electrode was 32%. These ratios are much smaller than that of conventional grinding wheels, 34-62% in nominal. The hardness of the WC-Co layer without abrasive was 102 HRRS, harder than a general vitrified bond wheel. Because the deposit of the WC-Co layer was very hard, tight gripping of grits can be also expected.
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  • Evaluation of Abrasive Layer through Grinding Process
    Katsushi FURUTANI, Hirotaka SUNADA
    2003 Volume 37 Issue 84 Pages 31-38
    Published: March 25, 2003
    Released on J-STAGE: March 12, 2010
    JOURNAL FREE ACCESS
    This paper deals with a fabrication method for a grinding wheel by electrical discharge machining (EDM) and its evaluation through practical grinding. When the total life of the grinding wheel has ended, the grinding wheel is thrown away although its core is still usable. Depositing an abrasive layer by EDM with a green compact electrode is proposed to fabricate a recyclable grinding wheel for cost reduction. Some metallic disks were practically ground with a #400 SiC abrasive layer. The grinding ratio against steel was 6.9. Then the deposit process for a cylinder was proposed to fabricate and recycle a mounted wheel. The maximum difference for a thickness of 300μm was 10μm by the shape feedback machining method. Although the additional layer was deposited without any cleaning in the recycle process, it performed as well as a new one. Therefore, the abrasive layer fabricated by EDM can be used for grinding.
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  • Advantage of Machinability and Molding properties
    Mitsuo OKAMI
    2003 Volume 37 Issue 84 Pages 39-44
    Published: March 25, 2003
    Released on J-STAGE: March 12, 2010
    JOURNAL FREE ACCESS
    Download PDF (5913K)
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