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Volume 37, Issue 9
Displaying 1-11 of 11 articles from this issue
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Ken-ichiro AOKI1987 Volume 37 Issue 9 Pages 573-574
Published: September 30, 1987
Released on J-STAGE: July 23, 2008
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Kenji ASAKURA, Nobuo KOBAYASHI, Masahide KOHZU1987 Volume 37 Issue 9 Pages 575-580
Published: September 30, 1987
Released on J-STAGE: July 23, 2008
JOURNAL FREE ACCESSSoft aluminum blanks having a coaxial circular hole were formed by drawing in which lateral fluid pressure was applied in combination with hole flanging. Two different methods, hole flanging after deep drawing and deep drawing after hole flanging, were tested. Sufficiently deep cylinders widely flanged are produced by both methods. In forming by the former method, the drawing force consists of two components caused by punch pressure and lateral fluid pressure. The component caused by lateral fluid pressure occupies most of the drawing force. The product more accurate in dimension of its inner cylindrical surface is finished by the latter method.View full abstractDownload PDF (1045K) -
Matsufumi TAKAYA1987 Volume 37 Issue 9 Pages 581-586
Published: September 30, 1987
Released on J-STAGE: July 23, 2008
JOURNAL FREE ACCESSAnodic polarization behaviors of magnesium in KOH solutions containing Al(OH)3, KF and Na3PO4 were examined by the use of potentiostat technique. The depth profile of aluminum distribution in coatings was investigated by secondary ion mass spectrometry. Film composition was measured by X-ray diffraction. Formation of passive coatings in KF added solution requires lower current density. Aluminum distribution in coatings with break down is denser than that in passive coatings. The coating with break down is composed of a mixture of MgO and MgAl2O4.View full abstractDownload PDF (1765K) -
Goroh ITOH, Bin-Lung OU, Hisashi SUZUKI, Motohiro KANNO1987 Volume 37 Issue 9 Pages 587-594
Published: September 30, 1987
Released on J-STAGE: July 23, 2008
JOURNAL FREE ACCESSRecrystallization and aging phenomena of Al-5.5%Zn-2.3%Mg-1.5%Cu alloys with 0.2%Cr or 0.1%Zr (Fe ≤O.003%) were examined in relation to impurity Si content up to 0.3%. Recrystallization both in Cr and Zr-bearing alloys was suppressed with increasing Si content up to 0.03% and accelerated over 0.03%. This was attributed to the fact that both the numerical density of fine dispersoids and the amount of coarse constituent particles increased as Si content in-creased. Fraction recrystallized was lower in any Si contained alloy than in the Si free alloy. Preferential precipitation on the dispersoids easily took place during aging at elevated temperatures especially in the Cr-bearing alloy irrespective of Si content. This seemed to mask the reduction in age-hardenability at elevated temperatures expected from the reduction of solute Mg concentration with increasing Si content by forming insoluble constituent particles of Mg2Si. It was thus concluded that impurity Si up to 0.3% should be favorable from the view point of suppression of recrystallization and should bring about harmful effects not so significantly on the aging characteristics.View full abstractDownload PDF (2919K) -
Kenzo KOBAYASHI, Ken-ichi SHIMIZU, Yasunori KURIMA1987 Volume 37 Issue 9 Pages 595-602
Published: September 30, 1987
Released on J-STAGE: July 23, 2008
JOURNAL FREE ACCESSThe development of γ'-alumina within the growing barrier oxide films on aluminum has been examined from the microscopic point of view. Under the present situation, where the structure of amorphous anodic alumina remains uncertain, it was assumed that the arrangement of oxygen ions in the amorphous alumina can be represented approximately by DRP model proposed by Bernal. An close examination of oxygen ion migration at the amorphous/γ'-crystalline alumina interface has shown that the migration of oxygen across the interface is accompanied by the loss of excess volume associated with oxygen ions in the amorphous phase. The excess volumes eventually agglomerate to form voids at the amorphous/γ'-crystalline alumina interface. It has been shown clearly that the amount of excess volume released at the amorphous/γ'-crystalline interface is considerably greater at the interface near to the oxide/electrolyte interface than at the interface near to the metal/oxide interface, implying preferential formation of void at the former interface. On the basis of DRP model, an explanation is also given to the origin of "highly ordered" amorphous alumina surroundingγ'-alumina crystals.View full abstractDownload PDF (1740K) -
Osami SERI, Kohsuke TAGASHIRA1987 Volume 37 Issue 9 Pages 603-607
Published: September 30, 1987
Released on J-STAGE: July 23, 2008
JOURNAL FREE ACCESSAluminum hydroxides were produced from AlCl3 solution. Their characteristics were studied in terms of corrosion product. When the aluminum hydroxide adheres over the surface of intermetallic compounds exposed on the surface of Al-Fe alloys, corrosion potential of Al-Fe alloys shifts to less noble. 0.1M NaCl solution containing AlCl3 0.01 to 0.1M plays a role of pH buffer. Its maximum pH is about 4.View full abstractDownload PDF (769K) -
Shigetoshi OGURA1987 Volume 37 Issue 9 Pages 608-613
Published: September 30, 1987
Released on J-STAGE: July 23, 2008
JOURNAL FREE ACCESSA new method has been developed for predicting oil staining in the annealing process for aluminum cold rolled sheets. A steam stripping method is applied in this predicting method to determine the amount of contaminants. The amount of existing gum, residue recovered by steam stripping, has good correlation to the staining tendency of contaminated rolling oils. Ths gum is mainly composed of heavy oil having molecular weight more than 740 on HPLC. This analytical method is useful to daily routine maintenance of rolling oils. It ensures accurate measurement and easy operation without expensive equipment. The critcal values of contaminants for production mills varies in accordance with the operating condition of rolling mills and strip materials. The critical content of contaminants of existent gum varies between 0.4 and 0.7%.View full abstractDownload PDF (614K) -
Kousuke ITO, Hiroshi OIKAWA1987 Volume 37 Issue 9 Pages 614-615
Published: September 30, 1987
Released on J-STAGE: July 23, 2008
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Kenzo KOBAYASHI, Ken-ichi SHIMIZU, Yoshihiro TSUDA1987 Volume 37 Issue 9 Pages 616-617
Published: September 30, 1987
Released on J-STAGE: July 23, 2008
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Zen-ichi TANABE1987 Volume 37 Issue 9 Pages 618-623
Published: September 30, 1987
Released on J-STAGE: July 23, 2008
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Yuzo HOSOI1987 Volume 37 Issue 9 Pages 624-635
Published: September 30, 1987
Released on J-STAGE: July 23, 2008
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