巻号一覧
57 巻, 8 号
選択された号の論文の6件中1～6を表示しています
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研究論文
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古島 剛, 真鍋 健一2007 年 57 巻 8 号 p. 351-356
発行日: 2007年
公開日: 2007/09/30
ジャーナル フリーDieless drawing technique can thin down tubes by combining locally heating and tensile deformation of tubes without dies and tools. In this study, the dieless drawing process is applied to non-circular 1100 and 3003 aluminum alloy extruded tubes with double hollow section for heat exchangers. Fundamental deformation behavior of the tubes in the dieless drawing is investigated experimentally. Multi-pass dieless drawing is performed for the tubes to obtain larger reduction in area. The limiting reduction in area of A3003 tubes is 40% larger than 35% of A1100 in a singles pass drawing. Reduction in area 57.75% is obtained by two-pass dieless drawing for A3003 tubes. Geometrical similarity law in cross section is satisfied for the aluminum extruded tubes with double-hollow-section. In addition, surface characteristic and microstructure of the tubes after the dieless drawing is observed to investigate the effect of microscopic factors on the deformation behavior and the drawability in the dieless drawing. The results show that the surface roughness of the tubes increases with increasing reduction in area. Furthermore, the rate of increasing surface roughness depends on the grain size of initial tubes. It is found that the microstructure and the surface characteristic affect the deformation behavior and the drawability in the dieless drawing.抄録全体を表示PDF形式でダウンロード (2222K) -
越智 秀, 山本 義秋, 山崎 貴司, 澤井 猛, 川井 五作, 小川 恒一2007 年 57 巻 8 号 p. 357-361
発行日: 2007年
公開日: 2007/09/30
ジャーナル フリーThe relationships between the deformation heat input at the upset stage and joint strength, and between upset burn-off length and joint strength were examined on 1050 pure aluminum to C1100 tough pitch copper friction-welded joints. Joint quality was evaluated from tensile strength and fatigue strength. It was found that the deformation heat input at the upset stage or the upset burn-off length could be correlated well with joint strength, and when the deformation heat input at the upset stage or upset burn-off length exceeded a certain value, a stable tensile strength was obtained. The mixing layer consists of intermetallic compounds and A1050 was formed at the weld interface, and joints having thick mixing layer fractured at the weld interface. Joint efficiencies of sound joints for the fatigue limit of the A1050 base metal was 88–100%. Judging from the fatigue limit, the sound joints could be produced when either the deformation heat input at the upset stage or the upset burn-off length exceeded a certain value.抄録全体を表示PDF形式でダウンロード (1000K) -
畑中 伸夫, 飯塚 高志, 高倉 章雄2007 年 57 巻 8 号 p. 362-365
発行日: 2007年
公開日: 2007/09/30
ジャーナル フリーRestoration tests were carried out using specimens bulged to different heights and diameters. The diameters use an Erichsen test device and a specially fabricated bulging die. Soft aluminum (Al–O) sheets were used as test specimens. The bulged sheets were compressed in the upper and lower plates of the material testing machine. The thickness of the specimens was changed from 0.4 to 2 mm. And the effect of thickness on the restoration behavior of the bulged specimens was investigated. The results of the experiments showed that some circular wrinkle patterns appeared on the sheet surface due to buckling at the bulged portion during compression when the bulged specimen was compressed to a flat sheet. Some restoration patterns were observed depending on the thickness of the material. The number of wrinkles formed after restoration was influenced by the thickness of the material, the height of the bulge and its diameter.抄録全体を表示PDF形式でダウンロード (821K) -
望月 隆, 森山 広思, 寺島 慶一2007 年 57 巻 8 号 p. 366-370
発行日: 2007年
公開日: 2007/09/30
ジャーナル フリーAnodic oxide films grown on rapidly quenched aluminum alloys containing 2 at% Ti, Zr, Ta, Nb or Hf were characterized. The capacitance of the film on each alloy was found to be related to the dielectric constant of the alloying metal oxide film. In addition, the capacitance was found to depend on the degree of the exposure of the alloyed metal to the electrolyte, due to aluminum dissolution during the anodic oxidation. Capacitance varied with time, temperature and pH of the electrolyte in the anodic oxidation process. An oxide film of the barrier type was observed on Al3Zr by TEM, whereas the oxidation film of the Al–Ti alloy had a dual structure consisting of an inner layer with lower TiO2 content and an outer one with higher TiO2 content. It is considered that these phenomena were caused by the preferential dissociation of aluminum in the anodic oxidation process.抄録全体を表示PDF形式でダウンロード (656K)
解説
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世利 修美2007 年 57 巻 8 号 p. 371-380
発行日: 2007年
公開日: 2007/11/30
ジャーナル フリーPDF形式でダウンロード (504K)
連載講座
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吉田 一也2007 年 57 巻 8 号 p. 381-388
発行日: 2007/08/30
公開日: 2021/06/30
ジャーナル フリーPDF形式でダウンロード (2009K)
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