Journal of Japan Institute of Light Metals
Online ISSN : 1880-8018
Print ISSN : 0451-5994
ISSN-L : 0451-5994
Volume 39, Issue 10
Displaying 1-10 of 10 articles from this issue
  • Takashi KUNIMOTO, Noritaka MORI
    1989 Volume 39 Issue 10 Pages 687-692
    Published: October 30, 1989
    Released on J-STAGE: October 30, 2008
    JOURNAL FREE ACCESS
    The deformation characteristics of the sandwich construction of the 5052 aluminum alloy corrugated-core in axial compression under static and dynamic loading have been investigated both theoretically and experimentally. The following results were obtained.
    (1) The dynamic ultimate compressive stresses converge on a value about 1.4 times larger than the static values with increase in the kinetic energy.
    (2) In spite of the combination of the elements, the static ultimate compressive stresses and the static mean crushing stresses agree approximately with the calculated values which are calculated with the effective width theory or the limit design method.
    (3) The dynamic mean crushing stresses approximate to the static calculated values.
    (4) The total impulse quantity is proportional to the momentum.
    Download PDF (643K)
  • Kanji TAKEUCHI
    1989 Volume 39 Issue 10 Pages 693-698
    Published: October 30, 1989
    Released on J-STAGE: October 30, 2008
    JOURNAL FREE ACCESS
    Billets of plasticine were extruded to the round rods, and the flow patterns were observed. Billets were made of black rods of plasticine which were alternatively wound by the black and white plates of plasticine. Flow patterns were observed which were produced by the four types of methods combined the rough and smooth surface conditions of the container and die, respectively. No dead metal zone was observed only when the surfaces of the die and container were smooth. Little difference was observed in the shape of the dead metal zones obtained at the different extrusion ratio, except the case near the die exit. The outside skin of the billet was extruded at the final stage. When the inner surface of the container was rough, the outside skin did not appear on the surface of the products. On the contrary, when the inner surface of the container was smooth the surface skin of billet flowed to the surface of the products over the surface of the dead metal zone. When the surface of the dummy block was rough the piping did not appear until the discard thickness reduced. The large die exit produced the large piping. The inside diameter of the piping slightly decreased with the decrease in the discard thickness.
    Download PDF (1079K)
  • Dian-bin WANG, Teruo OHASHI
    1989 Volume 39 Issue 10 Pages 699-704
    Published: October 30, 1989
    Released on J-STAGE: October 30, 2008
    JOURNAL FREE ACCESS
    A simple technique (fluxing method) employing the mixture of titanium fluoride and SiC whiskers was tested for the fabrication of SiC/aluminum matrix composites. Substantial mixing of whiskers with a molten aluminum-magnesium alloy was obtained only by stirring the liquid alloy covered with the above flux, and a good wettability of SiC whisker to liquid aluminum was demonstrated. EPMA and Auger electron analyses of the SiC/aluminum composites produced by the fluxing method showed some enrichment of titanium and carbon on the surface of SiC whiskers. It was suggested that the interface reaction between the whiskers and the molten aluminum could be suppressed by the formation of TiC thin layer on the surface of the whiskers.
    Download PDF (1299K)
  • Shinsaku HANASAKI, Mutsumi TOUGE, Eiji TANOKUBO, Yoshio HASEGAWA
    1989 Volume 39 Issue 10 Pages 705-709
    Published: October 30, 1989
    Released on J-STAGE: October 30, 2008
    JOURNAL FREE ACCESS
    This paper describes an experimental investigation of a micro-cutting to make clear the severe tool wear mechanism in hypereutectic Al-20%Si alloy. Tool wear of carbide tool is mainly induced by the mechanical scratching action with crushed primary Si particles. In situ observation by using SEM micro-cutting system is found to be very successful for the clarification of the interaction between crushed primary Si particles and a cutting edge of tool. Summary of the results are shown below. (1) Primary Si particles are crushed and/or fine grained in the shearing zone. A part of them are observed to collide directly with a cutting edge of tool by following the micro-cutting. This appears to be a cause of severe tool wear in turning of this alloy. (2) The direction of primary cracks in primary Si particles almost agree with those of principal stress under a compressive value by the elastic stress analysis.
    Download PDF (1568K)
  • Susumu IKENO, Shinji KIJIMA, Yasuhiro UETANI, Kenji MATSUDA, Shizuo TA ...
    1989 Volume 39 Issue 10 Pages 710-716
    Published: October 30, 1989
    Released on J-STAGE: October 30, 2008
    JOURNAL FREE ACCESS
    Various kinds of precipitates were observed in Al-1%Mg2Si base alloys by high resolution transmission electron microscopy (HRTEM). Analysis of elements was performed simultaneously by the attached energy dispersive X-ray spectroscope (EDX). HRTEM observation showed that a needle like precipitate in Al-1 wt%Mg2Si alloy had the hexagonal array of bright spots, corresponding to a hexagonal unit cell. The following orientation relationship with the matrix was obtained: (001)m_??_(0001)i. In a Mn addition alloy, a needle like precipitate was devided into several regions by the different array of bright spots. Thus a simple orientation relationship with the matrix was not obtained. In an excess Si alloy, some small precipitates with high Si content had been already coexisted among needle like precipitates at peak aged condition. In a Mn addition alloy, spherical precipitates with high Mn content were observed on the rod like precipitates which consist of Mg and Si at the early stage of aging at 400°C. At the later stage of aging, large flake or square shape precipitates containing Mn were observed after disappearence of rod like precipitates.
    Download PDF (1779K)
  • Tetsuya TAKAAI, Yoshihiro NAKAYAMA
    1989 Volume 39 Issue 10 Pages 717-723
    Published: October 30, 1989
    Released on J-STAGE: October 30, 2008
    JOURNAL FREE ACCESS
    Effect of test temperature on tensile properties of 1050 aluminum plate has been investigated at temperatures ranging from 473K to 4K for four kinds of specimens which are as rolled, recovered, partially recrystallized or fully recrystallized. The results obtained are as follows;
    1. Deformation is more unifrom at 4K than at temperatures above 77K resulting in a marked increase in the elongation to fracture at 4K.
    2. Proof stress increases almost linealy with decrease in test temperature, though there exists clear difference in the temperature dependence between fully recrystallized specimens and the specimens including a certain amount of residual stress.
    3. Below 200K all specimens show the parabolic increase in the ultimate tensile strength with decrease in the test temperature. The as rolled specimen only tends to neck at 4K and at strain rate of 3.3×10-4s-1. The temperature dependence of ultimate tensile strength corresponds to the difference in residual stress and microstructures.
    Download PDF (1104K)
  • Osami SERI, Shyuichi FURUYA, Noboru SOGA
    1989 Volume 39 Issue 10 Pages 724-729
    Published: October 30, 1989
    Released on J-STAGE: October 30, 2008
    JOURNAL FREE ACCESS
    The corrosion behaviors of the four kinds of Al-Cu alloys with different copper contents ranging from 0.36-1.30% were investigated in terms of the corrosion weight loss, micromorphology observations and measurements of the corrosion potentials. Increasing the content of copper in aluminum results in decreasing the corrosion resistance of aluminium. It is shown that the copper in solid solution has less effect on the corrosion resistance than the copper as intermetallic phases of CuAl2.
    Download PDF (1233K)
  • Osami SERI, Mitsunori IMAIZUMI, Kohsuke TAGASHIRA
    1989 Volume 39 Issue 10 Pages 730-734
    Published: October 30, 1989
    Released on J-STAGE: October 30, 2008
    JOURNAL FREE ACCESS
    When immersed in aerated 0.1M NaCl solution for 103 hours, Al-0.87%Cu and Al-1.30%Cu alloys give rise to pitting reactions to form cavities on the surface. It is found that the concentration of Cl- ions within the cavities which is predicted from the drop of corrosion potential is equivalent to that in 0.1M to 0.2M deaerated AlCl3 solution.
    Download PDF (679K)
  • Atsumi OHNO
    1989 Volume 39 Issue 10 Pages 735-740
    Published: October 30, 1989
    Released on J-STAGE: October 30, 2008
    JOURNAL FREE ACCESS
    Download PDF (1181K)
  • Hiromichi NAKAMURA
    1989 Volume 39 Issue 10 Pages 741-743
    Published: October 30, 1989
    Released on J-STAGE: October 30, 2008
    JOURNAL FREE ACCESS
    Download PDF (297K)
feedback
Top