Journal of The Japan Society of Electrical Machining Engineers
Online ISSN : 1881-0888
Print ISSN : 0387-754X
ISSN-L : 0387-754X
Volume 12, Issue 23
Displaying 1-5 of 5 articles from this issue
  • Yasuo KIMOTO, Katsunori TAMIYA, Shoichi HONDA, Toshiaki ANDO, Tomohiko ...
    1978 Volume 12 Issue 23 Pages 1-11
    Published: September 30, 1978
    Released on J-STAGE: March 12, 2010
    JOURNAL FREE ACCESS
    The electrolytic polishing of inner surface of large stainless steel vessels for chemical reactors has been reported recently for the purpose of decreasing the adherence of foul. But ordinary method of electrolytic polishing in strong acids is not always useful to apply to wide area because it necessitates pre-finishing of the surface and consumes much electric power.
    In this paper, experimental results performed by a new method, electrolytic polishing assisted by mechanical abrasion in solution of sodium nitrate are described.
    The roughness of the polished surface has been of 0.05-0.1μm Rmax and the adherence of the foul has been decreased to about one twentieth of that on mechanically polished surface.
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  • Anodic Dissolution Properties of Commercial Alloys
    Eiji MAKINO, Toshikazu SATO
    1978 Volume 12 Issue 23 Pages 12-23
    Published: September 30, 1978
    Released on J-STAGE: March 12, 2010
    JOURNAL FREE ACCESS
    The anodic properties involved in electrochemical machining of four heat-resistant nickel-base alloys and pure nickel were studied in NaCl and NaNO3 solutions. The polarization curve and dissolution current efficiency were measured in a flow channel cell. The results show that during electrochemical machining of Inconel 718 and Hastelloy X, anodic dissolution occurres only in the transpassive state and that the dissolution current efficiencies of these alloys are about 100% independent of the current densities in NaCl and NaNO3 solutions. From the above results it is estimated that in electrochemical machining of these alloys, good dimensional control cannot be achieved even in NaNO3 solution. The influences of the alloy composition on the anodic properties were discussed briefly.
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  • On the Discharge Phenomena in Electrolyte and the Electrochemical Metal Removal in ECDM
    Mamoru KUBOTA, Yuji TAMURA, Josui OMORI, Yasutaka HIRANO
    1978 Volume 12 Issue 23 Pages 24-33
    Published: September 30, 1978
    Released on J-STAGE: March 12, 2010
    JOURNAL FREE ACCESS
    Electric discharge phenomena in electrolyte and the electro-chemical metal removal in electrochemical discharge machining (ECDM) are studied experimentally to make clear the working mechanism of ECDM. The results obtained are as follows:
    (1) Discharge in electrolyte has some appearances by various electrode voltages and the unstable arc discharge is utilized for ECDM.
    (2) When the electrode gap is rather wide (about 0.2mm and more) discharge takes place between the electrode and the electrolyte, but in the usual ECDM of small working gap (less than 0.1mm) discharge seems to occur between the two electrodes.
    (3) In the single discharge by a rectangular wave pulse current generator an ignition delay of long duration is found out which suggests that the discharge occurs after the electrode surface has been covered by the gas evoluted in the electrochemical process.
    (4) Chemical analysis of iron ion in the drainage of ECDM shows that electrochemical removal in ECDM is nearely equal to the maximum rate of electrochemical removal even if the total removal rate changes.
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  • Relationship between the Shape of Impulse Discharged Crater and Machined Surface Roughness
    Yoshitsugu MUKOYAMA, Isao OGATA, Kiyoshi WATANABE
    1978 Volume 12 Issue 23 Pages 34-49
    Published: September 30, 1978
    Released on J-STAGE: March 12, 2010
    JOURNAL FREE ACCESS
    In the field of machining, the problem of the accuracy of machined surface is very consequence subject and the same in the electric discharge machining. However, the investigations on the formative process of the machined surface doesn't enough, because the gap phenomena in electrodes are extremly complicated.
    In this paper, in order to make clear the formation mechanism of the machined surface by electric discharge machining, the differences between the shape of the impulse discharged crater by using virsin electrode and by using the non-virsin elecrode, and the differences among the several sharp model electrodes (the pointed end diameter ∅0-∅1.0mm), and further the relationship between the shapes of thoes impulse discharged crater and the repetitional discharged surface, and other experiments were performed.
    In concequence, it became clear that the crater shapes of the repetitional discharged surface are extremely similar to the shape of the impulse discharged crater by using the non-virgin electrode and the sharp model electrodes which diameter ∅0-∅0.5mm.
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  • [in Japanese], [in Japanese]
    1978 Volume 12 Issue 23 Pages 50-70
    Published: September 30, 1978
    Released on J-STAGE: March 12, 2010
    JOURNAL FREE ACCESS
    Download PDF (2048K)
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