Journal of Japan Institute of Light Metals
Online ISSN : 1880-8018
Print ISSN : 0451-5994
ISSN-L : 0451-5994
Volume 18, Issue 2
Displaying 1-6 of 6 articles from this issue
  • Studies of fatigue strengths of aluminum alloys for welded construction (1st Report)
    Katsuji TAKEUCHI, Yoshihiko SUGIYAMA
    1968 Volume 18 Issue 2 Pages 71-80
    Published: February 28, 1968
    Released on J-STAGE: October 30, 2008
    JOURNAL FREE ACCESS
    In recent years, Al-Mg and Al-Zn-Mg alloys have widely been used as structural materials because of their good fusion weldability and progress in welding technique. This report summarizes several research experiments for fatigue properties of welded butt-joints of 5052, 5056, and 5083 aluminum alloys in MIG or TIG welding.
    The fatigue tests of the materials of 4-6mm in thickness were conducted with Schenck's plane-vibrating fatigue tester and the tests of round-bar specimens obtained from plates of 20mm in thickness were conducted with Ono's rotary-bending fatigue tester. The values of fatigue strengths were determined by 107 cycles.
    The number of blow holes had no remarkable effects on fatigue strength of butt-jointed specimen having reinforcement of weld. When there were no defects on the surfaces of the finished specimen, the fatigue strengths of welded specimen approached those values of annealed base metals. These results are summarized in Fig. 5.
    The effects of filler metals employed for the fatigue strength of 5083-O alloy in MIG welding are shown in Fig. 8. The effects of the shape of reinforcement of weld or presence of blow holes on the surfaces of the finished specimen were more powerful than those of filler metals employed.
    Above results were obtained from the experiments on materials of 4-6mm in thickness. In the welded butt-joint of 20mm in thickness, the fatigue strengths of finished round-bar specimens, having welded zone in parallel part, were about 33% lower than those of the base metals. These values of the strengths of the specimens approximately corresponded to those of the cast materials as shown in Table 10.
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  • Tsuneo TAKAHASHI, Yoshikazu KOBAYASHI
    1968 Volume 18 Issue 2 Pages 81-87
    Published: February 28, 1968
    Released on J-STAGE: October 30, 2008
    JOURNAL FREE ACCESS
    The texture of aluminum rods developed by the extrusion under various conditions was studied. The tests were conducted by varying extruding temperature, position of rod, and angle of dying. The results obtained were as follows.
    (1) Extruded aluminum rod showed cyclic fibrous structure, and the planes having high degree of texture were (112) [111], (213) [111], (178) [111], (001) [100], and (012) [100].
    (2) The amount of <100> structure component was larger with the rise of extruding temperature, and that at the middle part of the rod (250mm from the tip) was greater than that at its front end (60mm from the tip), which showed that the amount gradually increased from the end to the middle owing to the recrystallization during extrusion.
    (3) In the position adjacent to the angle of dying, the amount of <100> component was larger with the increase of angle.
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  • Shigeo ZAIMA, Susumu KAMO, Yoshioki HIROSE
    1968 Volume 18 Issue 2 Pages 88-96
    Published: February 28, 1968
    Released on J-STAGE: October 30, 2008
    JOURNAL FREE ACCESS
    Being continued from the tests of AZ63 in the previous report, cutting tests were conducted for turning machinability on magnesium casting alloys, i.e., AZ96-T6 and AZ92-T6. The tests were conducted for the determination of machinability by the results of cutting resistance, roughness of finished surface, chips treatment, chips firing, etc.
    The results obtained were as follows.
    There was no great difference of cutting resistance between AZ91 and AZ92 and their resistances were slightly higher than that of AZ63, but they were not so high as compared with those of other materials. The cut surface of the both materials were considerably well finished, which showed better surface than that of aluminum alloys. The chips of AZ91 were in shorter fragment than those of AZ92 so that the former was easier in treatment than the latter. In these experiments, these was almost no risk of firing in cutting of AZ92 as AZ63, but the chips of AZ91 were easy to fire in cutting. The risk of firing was more frequent in smaller depth of cut, smaller feed, and higher cutting speed.
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  • Studies on hyper-eutectic Al-Mn alloys (4th Report)
    Riei ICHIKAWA, Teruo OHASHI
    1968 Volume 18 Issue 2 Pages 97-105
    Published: February 28, 1968
    Released on J-STAGE: October 30, 2008
    JOURNAL FREE ACCESS
    The thermal stability of strongly saturated solid solution obtained by rapid cooling from the molten state of Al-3% Mn alloys containing each one of the following 3rd elements (Ag, Cu, Mg, Si and Zn) was studied by means of dilatometer, electron microscope, hardness test etc.
    The results obtained were as follows; The curves obtained by differential dilatation were showed that two stages of the decomposition of supersaturated solid solution by the precipitation of Al6Mn and other compounds were evident in Al-3% Mn-2% Cu and Al-3% Mn-0.5% Si alloys. However, only one stage was evident in other alloys.
    The change in length by isothermal heat-treatment was not found at 300°C for 500hr, in Al-3%Mn and Al-3%Mn-2% Zn alloys. However, expansion and contraction were observed in other alloys. In any of test alloys, no remarkable age-hardening effects were found and the hardness as cast was maintained for a long period at high temperature independent of the change in expansion or contraction by aging.
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  • Tsuneo TAKAHASHI, Osamu NAKAMURA, Masaoki HASHIMOTO
    1968 Volume 18 Issue 2 Pages 106-113
    Published: February 28, 1968
    Released on J-STAGE: October 30, 2008
    JOURNAL FREE ACCESS
    It was found that production of ears in deep drawing of aluminum sheets depended upon many factors such as chemical composition, heat treatment, reduction ratio, etc. Especially, in 2S aluminum, ears varied according to the content ratio of Fe/Si.
    The investigation of ears was undertaken for 5 sorts of aluminum sheets having the following ratios of Fe/Si: 5, 1.53, 0.39, 0.29, and 0.19, Then, the relation between ears and aggregate structure was also investigated in this study.
    The results obtained were summarized as follows.
    (1) Columnar crystals in slabs were longer when the ratio of Fe/Si was smaller.
    (2) In aluminum sheets having Fe/Si ratio of 0.39, ears were produced in 0-90°direction. However, in other sheets, they were produced in 45°direction at above recrystallization temperature. With respect to the total content of (Fe+Si), the direction of ears shifted to 0-90°with the higher purity of 2S aluminum. These results corresponded well with those of pole figures.
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  • Ryuzo KOMATSU
    1968 Volume 18 Issue 2 Pages 114-123
    Published: February 28, 1968
    Released on J-STAGE: October 30, 2008
    JOURNAL FREE ACCESS
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