Journal of Japan Institute of Light Metals
Online ISSN : 1880-8018
Print ISSN : 0451-5994
ISSN-L : 0451-5994
Volume 30, Issue 1
Displaying 1-9 of 9 articles from this issue
  • [in Japanese]
    1980 Volume 30 Issue 1 Pages 1
    Published: January 30, 1980
    Released on J-STAGE: March 14, 2011
    JOURNAL FREE ACCESS
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  • Hisashi SUZUKI, Motohiro KANNO, Goroh ITOH
    1980 Volume 30 Issue 1 Pages 3-10
    Published: January 30, 1980
    Released on J-STAGE: March 14, 2011
    JOURNAL FREE ACCESS
    The aging phenomena of A1-1 and 2% Cu alloys containing Sn up to 0.136% at aging temperatures from 0° to 100°C were studied by means of electric resistivity measurements and high-resolution transmission electron microscopy. The aging rate of ternary A1-2 % Cu-Sn alloys is retarded compared with that of Al-Cu binary alloy at aging temperatures 0° to 75°C. The ternary A1-1% Cu-Sn alloy has the faster aging rate at 50°-75°C than the binary A1-1%Cu alloy. These noticeable facts would be explained by considering secondary defects formed at the early stage of aging. The secondary defects are different in their characteristics between the binary and ternary alloys and seem to play different roles of sink or source for vacancies according to the aging temperature and copper content.
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  • Yoshishige TSUMURA, Akisaku SAKAKIBARA, Katsusaburo TOYODA, Nobutoshi ...
    1980 Volume 30 Issue 1 Pages 11-17
    Published: January 30, 1980
    Released on J-STAGE: March 14, 2011
    JOURNAL FREE ACCESS
    Factors governing the recovery efficiency of aluminum in an aluminum chloride bath electrolysis at 160° to 260°C were examined. Dehydrating current loss of electrolyte is 3.03 to 9.09 Ah/kg electrolyte depending on water content in aluminum chloride. Chlorinating loss remarkably increases at the bath temperature above 220°C and reaches to 5.76% at 260°C Filtering loss is not so high as about 0.25% at 180° to 260°C Melting loss depends on temperatures so considerably that the loss is 10.30% at 160°C and is reduced down to 2.75% at 260°C because of improvement in the deposited aluminum shape. Current efficiency of deposited aluminum is almost 98% independently of the bath temperature. The loss of current efficiency about 2% corresponds to the dehydrating loss by moisture of air during electrolysis. Using an anti-chlorinating diaphragm leads to recovery efficiency improved to 94.7% at 260°C.
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  • Yoshizo NAKATANI, Tadakazu OHNISHI, Chikara OKADA, Shigeru KAMINISHI
    1980 Volume 30 Issue 1 Pages 18-25
    Published: January 30, 1980
    Released on J-STAGE: March 14, 2011
    JOURNAL FREE ACCESS
    Al-1.1 to 4.1%Fe alloys were directionally solidified at solidification rates 30 to 1, 000 μm/sec under temperature gradient 50 to 70°C/cm. Seven ranges of microstructures are classified depending on compositions and solidification rates. A metastable Al-FeAl6 eutectic grows at the rate above 130, um/sec independing on compositions. A coupled region of Al-FeAl6 eutectic lies at Fe 2.5 to 3.2%, in which the shape of FeAl6 changes from ribbon to rod-like with increase of solidification rates. It takes a fine rod-type regular eutectic at the rates above 500 μm/sec. The interphase spacing of FeAl6 λ and the solidification rate R are : Rλ2 = 270 μm3/sec. A rod-type regular eutectic has the maximum strength about 27 kg/mm2 two times or more than the strength of Al-FeAl6 eutectic. The Al-FeAl6 eutectic also has the strength about two times larger than that of Al-FeAl3 eutectic at 200° and 300°C. Typical stress-strain curves and fractographs are represented.
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  • Shiro SATO, Noboru OKOSHI
    1980 Volume 30 Issue 1 Pages 26-30
    Published: January 30, 1980
    Released on J-STAGE: March 14, 2011
    JOURNAL FREE ACCESS
    Alternate bending tests were conducted on sheet specimens of 6 mm thickness having a stamped mark at the central part of surface. The fatigue strength at 107 cycles of specimens having stamped depths 0.18, 0.28 and 0.43 mm decreases by 9, 15 and 23% respectively as compared with that of the smooth surface. The fatigue tests were also carried out on flat specimens with a small central hole. The notch sensitivity of 7178-T6 alloy is slightly less than that of 7075-T6 alloy reported by Fukai and Takeuchi.
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  • Mikio KODAKA, Tetsuo SATO, Yasuo KIMURA
    1980 Volume 30 Issue 1 Pages 31-36
    Published: January 30, 1980
    Released on J-STAGE: March 14, 2011
    JOURNAL FREE ACCESS
    Effects of such defects as inclusions and porosities on mechanical properties of A1-10%Mg alloy were studied using a filter. Most of inclusions in a molten metal are MgO. Filtering through a bed of Al2Os balls of 3 to 5 mm in diameter or MgO flakes effectively removes inclusions. The refining grade of molten metal is determined from defects area in the fracture surface. The defects area correlates with ultimate tensile strength, elongation and impact values. The larger the defect is, the lower the mechanical properties fall. When inclusions are small in size and number, observation of the polished surface using a quantitative television microscope is valid in estimation of quality for Al-Mg alloys.
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  • Senri IKEDA, Keisuke IKEDA, Eihachiro TANAKA
    1980 Volume 30 Issue 1 Pages 37-43
    Published: January 30, 1980
    Released on J-STAGE: March 14, 2011
    JOURNAL FREE ACCESS
    An upper bound analysis was made. The dead zone is formed either at extrusion ratios less than 10 for indirect extrusion with frictionless flat dies or independently of reduction under the sticking friction. The experimental data using lubricated dies do not necessarily agree with the prediction. It appears necessary to examine wheather the dead metal predicted from the upper bound approach is an entirely rigid body or not. There exists a region similar to the dead zone in front of the die face without lubrication in agreement with the prediction from the upper bound analysis. The region is an uncommon arciform-type and does not entirely remain stationary. Such a feature found in indirect extrusion without lubrication will increase the possibility that the oxide skin of the billet is forced to flow into the product and gives rise to the extrusion defect.
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  • Shiro KOHARA
    1980 Volume 30 Issue 1 Pages 44-52
    Published: January 30, 1980
    Released on J-STAGE: August 17, 2011
    JOURNAL FREE ACCESS
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  • Mikio KANEHARA, Fumio MOCHIZUKI
    1980 Volume 30 Issue 1 Pages 53-61
    Published: January 30, 1980
    Released on J-STAGE: March 14, 2011
    JOURNAL FREE ACCESS
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