1988 Fiscal Year Final Research Report Summary
Basic Experiment of Etching of the Ceramic Surface by Electrolytic/Electro-Discharge Composit Machining Method
Project/Area Number |
62470058
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Research Category |
Grant-in-Aid for General Scientific Research (B)
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Allocation Type | Single-year Grants |
Research Field |
金属材料(含表面処理・腐食防食)
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Research Institution | The University of Tokyo |
Principal Investigator |
TSUJIKAWA Shigeo Faculty of Engineering, 工学部, 教授 (20011166)
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Co-Investigator(Kenkyū-buntansha) |
SHINOHARA Tadashi Faculty of Engineering, 工学部, 講師 (70187376)
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Project Period (FY) |
1987 – 1988
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Keywords | Ceramcs / Alumina / SiC / Machinability of Ceramics / Combined Machining / Electro-Discharge Machining |
Research Abstract |
An experimental investigation of the etching of the surface of ceramic materials was carried out by means of electro-discharge machining method in electrolyte solutions. Specimens of alumina or SiC ceramics were immersed in 0.01 - 1 mol/l NaOH, HCl, H_3PO_4, NaH_2PO_4, Na_2HPO_4 and Na_3PO_4 solutions. 0.8 mm tungsten wire was used as a tool electrode and it was pressed to the specimen. The maximum penetration depth and shape of crater depend on (1) kinds of electrolyte and its concentration, (2) applied voltage between tool electrode and counter electrode and (3) polarity of it. Craters in case of negative tool electrode were deeper than those in case of positive tool electrode. Two types of craters were observed. The deepest portion corresponded to the center of crater (TYpe I) in case of the deep crater and corresponded to the edge of crater (TYpe II) in case of the shallow crater. It was observed that (1) minor composition of alumina ceramic, which existed at the grain boundary of alumina grain, was attacked at the early stage and then alumina grain broke away, and that (2) alumina in Na_2HPO_4 or Na_3PO_4 solutions gave the good results. It was also observed that (1) SiC in 0.01 or 0.1 mol/l NaOH soultion gave the good results and that (2) SiC grain itself was attacked in these solutions.
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