巻号一覧
25 巻 (1991)
- 50 号 p. 1-
- 49 号 p. 1-
25 巻, 50 号
選択された号の論文の5件中1～5を表示しています
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焼戻し処理による薄板加工面曲率変化と表面組織緒方 勲, 向山 芳世, 日原 政彦1991 年 25 巻 50 号 p. 1-12
発行日: 1991/11/30
公開日: 2010/03/12
ジャーナル フリーWhen a thin plate is machined by EDM on one side, a certain curvature results owing to tensile residual stress generated on the surface of the workpiece. If the machined plate is tempered, some change in curvature of the thin plate appears to occur due to reduction in residual stress and changes in the degenerated layers.
This study was conducted to examine changes in curvature of a machined thin plate under various tempering conditions, in relation to those in the properties (phase changes) of the machined surface, using an X-ray diffractometer
Reduction in residual stress was concluded to occur due to stress relaxation, phase changes (transformation of γ Fe to α Fe) and the precipitation of carbides (Fe3C, M7C3). Change in curvature of thin plate was essentially the same as that noted by the X-ray stress measuring method. As a result, there occurs considerable plastic deformations (slip, twinning and lattice defects) of the EDM surface, owing to thermal effects.抄録全体を表示PDF形式でダウンロード (2730K) -
後藤 英和, 土屋 八郎, 片岡 秀直1991 年 25 巻 50 号 p. 13-22
発行日: 1991/11/30
公開日: 2010/03/12
ジャーナル フリーCutting characteristics of ceramics (Al2O3, ZrO2 and Si3N4) by using localized reactive gas plasma were investigated theoretically and experimentally. Applying a breakdown voltage between two needle shaped Pt electrodes which are facing each other and holding a ceramic material (t0.6-2mm) between them in etching gas (1-2atm), repetitive discharge (1-15kHz) can be induced between the two electrodes along the material surface. Then a linearly localized reactive gas plasma whose diameter is about 40-60μm can be generated along the material surface and cutting process proceeds with the chemical reaction between the material surface and the reactive gas molecules generated in the plasma. Experimental results are as follows. Etching gas, gas pressure, gas flow rate, electrode gap length and resistance of discharge circuit were the parameters changed. Gas pressure was the most effective parameter to increase cutting rate. In the case of Al2O3 (t600μm), the cutting rate obtained in 2atm SF6 gas was 600μm/min. The cutting rate of Si3N4 was 2-3 times greater than that of Al2O3. ZrO2 was unable to be cut because a thermally affected layer was generated on the surface along the gas plasma.抄録全体を表示PDF形式でダウンロード (3612K) -
後藤 昭弘, 福井 雅彦, 木下 夏夫1991 年 25 巻 50 号 p. 23-31
発行日: 1991/11/30
公開日: 2010/03/12
ジャーナル フリーNeed for technique to dig curved tunnnel into metal is becoming increase. For example, in a field of the mould injection, they expect such a technique to appear, because it will improve the precision of injection. However, no study has been done to realize it for now.
This paper deals with this new technique making use of EDM. we name it “Mole-EDM” for it is like a mole digging a tunnel into the ground.
In this paper, the mechanism and the way of control are explained. The Mole-EDM machime's shape is like a bar which can be bent, and the SMA (shape memory alloy) is used as an actuater. This time the ultrasonic wave is used to detect the form of tunnels digged by the Mole-EDM.抄録全体を表示PDF形式でダウンロード (2167K) -
単発放電における残留溶融層および熱変質層の評価宮崎 真, 土屋 八郎, 乾 倫郎1991 年 25 巻 50 号 p. 32-38
発行日: 1991/11/30
公開日: 2010/03/12
ジャーナル フリーIn electric discharge machining, it is wellknown that any molten part remains as a melting remnant layer and under it a thermal affected layer is formed. This paper deals with an estimation of those layers based on the microstructure surrounding the impulsed discharge crater. The boundary between the melting remnant and the thermal affected layer can be clear. Furthermore, Ac1 and Ac3 transformation due to the higher heating and cooling action in an extremely short time are observed on the thermal affected layer. The Ac1 and Ac3 transformation temperatures are about 800°C and 900°C, respectively. The results present several thermal data for confirming the validity of a thermal conductive model for theoretical analysis of the size and form of the crater.抄録全体を表示PDF形式でダウンロード (6262K) -
放電加工面における2次元評価との関係向山 芳世, 河田 明義1991 年 25 巻 50 号 p. 39-52
発行日: 1991/11/30
公開日: 2010/03/12
ジャーナル フリー通常, 加工面あらさの評価は2次元的情はに因ることが多い。しかし, 極問状態の不確定要素の影響を大きく受ける液中放電除去現象利用の加工では, 加工面が複雑・多様な形状であり, 統計的処理をもってしても, 加工面あらさの厳密な把握は困難なことが多い。
本報告は, 触針式2次元表面あらさ測定機の改良とソフトウェアの付加により, 単発放電こんならびに繰返し放電加工面のあらさの3次元測定・評価を行った。その結果, 放電こんと加工面の放電除去部, 盛り上がり部の最大値の真の数値を把握できた。また, 2次元測定値と3次元測定値の関係を数的に明確にするとともに, 単発放電こんの除去部ならびに盛り上がり部の体積, 占有面積, 重量等の測定評価を可能にした。抄録全体を表示PDF形式でダウンロード (3319K)
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