Journal of Japan Institute of Light Metals
Online ISSN : 1880-8018
Print ISSN : 0451-5994
ISSN-L : 0451-5994
Volume 40, Issue 3
Displaying 1-14 of 14 articles from this issue
  • Katsushige ADACHI, Koichi OGAWA, Norihisa ARAI, Hisashi IGAKI
    1990 Volume 40 Issue 3 Pages 171-175
    Published: March 30, 1990
    Released on J-STAGE: October 30, 2008
    JOURNAL FREE ACCESS
    Cobalt high speed steel drills brazed with sheathed thermocouples were utilized in the measuring cutting temperature of the drill face, and the relationship between the cutting temperature and the cutting characteristics (cutting force, drill wear) was investigated. The temperature at the drill face during low frequency vibratory drilling was lower than that in the conventional drilling. Low frequency vibratory drilling also showed more effectiveness in the drilling of aluminum than the conventional drilling.
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  • Gaohui WU, Norio KONO, Hisafuji WATANABE, Tsuneo TAKAHASHI
    1990 Volume 40 Issue 3 Pages 176-181
    Published: March 30, 1990
    Released on J-STAGE: October 30, 2008
    JOURNAL FREE ACCESS
    The squeeze exhaust casting process for Al2O3 particles dispersed 6061 aluminum alloy composite materials was studied with a special casting mold having vent holes on its bottom, and was compared with the conventional squeeze casting process. The molten metal permeated gradually from top to bottom of the mold and almost all gases escaped from cavity simultaneously, and it had been made possible to obtain the composite containing 0.15μm diameter fine Al2O3 particle with 20-40% in volume fraction. The structure of the composite obtained was fine and homogeneous, and the interstice fraction was less than 1%. The tensile strength of the extruded composite containing 30 volume percent of Al2O3 particles was 63kgf/mm2 and the elongation was 5% at room temperature. At 250°C the tensile strength becam 20kgf/mm2 and the elongation increased to 27%.
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  • Tadashi TAKEMOTO, Ikuo OKAMOTO, Shin-ichi FUJIUCHI, Masatoshi SAWATARI
    1990 Volume 40 Issue 3 Pages 182-187
    Published: March 30, 1990
    Released on J-STAGE: October 30, 2008
    JOURNAL FREE ACCESS
    Solderbility of aluminum was evaluated mainly by the wetting time obtained from the wetting force-time curves of a surface tension method. Used flux was composed from triethanolamine, ammonium fluoroborate and tin borofluoride. Increase of Sn-Zn solder bath temperature decreased the wetting time, Tw. The shortest Tw was shown in the Sn-20Zn solder in the temperature range of 300-400°C. At about 250°C, Sn-9Zn solder had the best solderbility. Sn-70Zn solder showed longer Tw than that of Sn-(20-40)Zn solders even at high temperatures more than 400°C. The ln (1/Tw) was proportional to the 1/T (T: solder bath temperature). The apparent activation energies were ranging 25.9-84.8kJ/mol. The change of activation energies with solder composition was similar to that of interdiffusion of molten Sn-Zn system. Increase of magnesium content in the base metal drastically decreased the solderbility. Cleaning in the hydrofluoric acid improved solderbility, however, commercial alloys with more than 3.5%Mg scarcely wetted.
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  • Yoshihiro SHIMIZU, Yoji AWANO, Motoyuki NAKAMURA
    1990 Volume 40 Issue 3 Pages 188-194
    Published: March 30, 1990
    Released on J-STAGE: October 30, 2008
    JOURNAL FREE ACCESS
    In Al-Si-Cu alloy castings, the eutectic melting heat treatment promoted spheroidization of eutectic Si and increased the impact strength. In this study, this treatment was applied to Al-Si-Cu alloy castings modified with Sr. The impact strength of high purity alloy castings increased by Sr-and Na-modification. The strength of modified alloy castings was slightly improved by this heat treatment. On the other hand, the strength of production purity alloy castings increased by only Sr-modification, and was significantly improved by eutectic melting heat treatment. The impact strength of production purity alloy castings was dependent on the shape and size of both eutectic Si phase and Fe bearing compounds which were changed by Sr-or Na-modification and solution heat treatment.
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  • Yoshikazu IMAI, Keiji UEMURA, Hiroshi ICHIKAWA, Toshikatsu ISHIKAWA
    1990 Volume 40 Issue 3 Pages 195-201
    Published: March 30, 1990
    Released on J-STAGE: October 30, 2008
    JOURNAL FREE ACCESS
    Preform wires, which were organosilicone polymer (polycarbosilane) derived SiC fiber reinforced Al composite were high specific strength and high specific modulus. The thermal stability of those preform wires were investigated. Before and after exposure test at elevated temperature, the tensile strength of wires and extracted fibers were measured at room temperature. There was no degradation in the strength at 623K until 3600ks. In higher temperature, the strength of wires began to decrease gradually after about 108ks at 723K and after about 36ks at 773K. The limit of thermal stability was estimated to be about 700K for the preform wires.
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  • Yoshikazu IMAI, Michio TAKEDA, Hiroshi ICHIKAWA, Toshikatsu ISHIKAWA
    1990 Volume 40 Issue 3 Pages 202-208
    Published: March 30, 1990
    Released on J-STAGE: October 30, 2008
    JOURNAL FREE ACCESS
    Preform wires, which are organosilicone polymer (polycarbosilane) derived SiC fiber reinforced Al composite are expected to be a useful semi-finished material for fabricating FRM. High temperature strength and thermal stability of those preform wires were investigated. The tensile strength of wires at 723K was about 85% of the strength at room temperature. The degradation in the strength was not due to degradation in the fiber strength, and was due to degradation in the transmission ability of stress from the matrix to the fibers. Those preform wires can be used as semi-finished materials without the degradation of strength during fabricating FRM at elevated temperature.
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  • Shotaro MOROZUMI, Takeo SAKURAI, Tomoya MINEGISHI, Kazuyoshi KATO, Hir ...
    1990 Volume 40 Issue 3 Pages 209-214
    Published: March 30, 1990
    Released on J-STAGE: October 30, 2008
    JOURNAL FREE ACCESS
    Bonding interfaces of friction-welded 1050 aluminum/AZ31 magnesium alloy joints, before and after annealing at 673K for 1h, were examined by tensile test for bonding strength, by optical micrography, EPMA and X-ray analysis for phases in the interfacial reaction. Bonding strength of the friction-welded joints in the as-welded state was dependent on the thickness of interfacial reaction layer. The thinner layer had resulted in the higher bonding strength (about 45MPa). The interfacial reaction layer consisted of two sublayers of compounds (Al3Mg2 and Al12Mg17). The former compound predominantly grew by the annealing. That fact resulted in the brittlement of the interface.
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  • Hiroshi ASANUMA, Mitsuji HIROHASHI, Osamu HAYAMA, Akihiro CHO
    1990 Volume 40 Issue 3 Pages 215-220
    Published: March 30, 1990
    Released on J-STAGE: October 30, 2008
    JOURNAL FREE ACCESS
    For each matrix powder size, the tensile strength of composite increased proportionally with increasing volume fraction of the whisker, Vf, up to a critical value, (Vf)c, beyond which the strength was holded. (Vf)c increased with decreasing powder size. Thus, the composite produced with finer matrix powder was effectively strengthened by the whisker up to higher Vf. The amount of whisker per unit surface area of matrix powder calculated for each size of powder at (Vf)c coincided approximately with each other. The specific amount of whisker was considered to be a limitation to effectively reinforce the matrix. As for the effect of heat treatment on the strength of composite, it was 20% increased by heating at 913 K for about 30ks. On the other hand, the prolonged heat treatment reduced the strength by causing remarkable reaction between the whisker and the matrix.
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  • Yasuyuki INOSE, Junichi KANEKO, Makoto SUGAMATA
    1990 Volume 40 Issue 3 Pages 221-228
    Published: March 30, 1990
    Released on J-STAGE: October 30, 2008
    JOURNAL FREE ACCESS
    SiC whisker reinforced composites with AZ31 magnesium alloy matrix were experimentally fabricated by high pressure infiltration of the alloy melt and subsequent hot extrusion. Elastic modulus of the composites increased with increasing the whisker Vf and hence specific elastic modulus of the composites were appreciably higher than those of any high strength metallic materials. The proof stress and tensile strength of the composites were the highest for 20% whisker Vf. However, specific tensile strength of the 20% Vf composites remained nearly the same as that of the high strength aluminum alloys. At 573K, the tensile strength of the composites became almost the same as that of the matrix alloy AZ31. Torsional fatigue strength of the composites was appreciably higher than that of the matrix alloy.
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  • Hiroshi NAKASHIMA, Kazuhiro ODA
    1990 Volume 40 Issue 3 Pages 229-236
    Published: March 30, 1990
    Released on J-STAGE: October 30, 2008
    JOURNAL FREE ACCESS
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  • Hiroshi FUKUTOMI
    1990 Volume 40 Issue 3 Pages 237-238
    Published: March 30, 1990
    Released on J-STAGE: October 30, 2008
    JOURNAL FREE ACCESS
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  • Chozo FUJIKURA
    1990 Volume 40 Issue 3 Pages 239-255
    Published: March 30, 1990
    Released on J-STAGE: October 30, 2008
    JOURNAL FREE ACCESS
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  • Yasuhiko MIYAKE
    1990 Volume 40 Issue 3 Pages 256-258
    Published: March 30, 1990
    Released on J-STAGE: October 30, 2008
    JOURNAL FREE ACCESS
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  • 1990 Volume 40 Issue 3 Pages iv
    Published: 1990
    Released on J-STAGE: October 30, 2008
    JOURNAL FREE ACCESS
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