Journal of the Japan Society of Powder and Powder Metallurgy
Online ISSN : 1880-9014
Print ISSN : 0532-8799
ISSN-L : 0532-8799
Volume 20, Issue 5
Displaying 1-5 of 5 articles from this issue
  • [in Japanese]
    1973 Volume 20 Issue 5 Pages 137-141
    Published: October 25, 1973
    Released on J-STAGE: May 22, 2009
    JOURNAL FREE ACCESS
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  • Moriya Oyane, Takashi Kawakami, Susumu Shima
    1973 Volume 20 Issue 5 Pages 142-146
    Published: October 25, 1973
    Released on J-STAGE: May 22, 2009
    JOURNAL FREE ACCESS
    The theory, already proposed by the authors, is modified. A constant stress-strain curve is obtained for the matrix metal from simple compression of sintered copper with different density ratios.
    From the theory the relationship between the density ratio and compressive strain is obtained for the case of simple compression and compared with the experimental results for sintered copper.
    By introducing the concept of a reduced pressure, that is, tool pressure divided by instantaneous flow stress, it is possible to develop a generalised curve of density ratio versus reduced pressure which may have some general applicability to closed die compression of sintered metals. This curve is utilized to obtain a relationship between density ratio and tool pressure, being compared with the experimental results for sintered copper.
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  • Shunji Ito, Yasuaki Morioka, Ichiya Endo
    1973 Volume 20 Issue 5 Pages 147-153
    Published: October 25, 1973
    Released on J-STAGE: May 22, 2009
    JOURNAL FREE ACCESS
    Iron powders were made from iron oxides by the method of reduction with coke and subsequently with hydrogen. These iron oxides were obtained as a by-product from waste pickling liquor in steel industry. Various properties of these iron powders were tested and measured. The characteristics obtained were as follows:
    1) Iron powders made from fine oxide particles had low apparent density and irregular shapes compared with those from ore and mill-scale.
    2) Compressibility was not so good, but compactibility was excellent. Mechanical strength of green compacts was very high, and the rattler value was very small.
    3) The mechanical strength of these sintered compacts was high in comparison with commercial reduced iron powders and the elongation was especially high at high sintered density.
    4) The lower is the hydrogen loss of iron powders, the higher both green and sintered densities were obtained then dimensional change (shrinkage) was small and the elongation was much improved.
    It was found that these iron powders produced by reduction of iron oxides, which were made as a byproduct from waste pickling liquor, had many interesting properties, especially in compactibility and mechanical strength of both green and sintered compacts.
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  • Tomeji Ohno, Masao Takahashi, Norio Tsubouchi
    1973 Volume 20 Issue 5 Pages 154-160
    Published: October 25, 1973
    Released on J-STAGE: December 04, 2009
    JOURNAL FREE ACCESS
    Influence of SiO2 addition on formation process of Pb(Ti⋅Zr)O3 solid solution was studied. Powdered PbO, TiO2, ZrO2 and SiO2 were used as raw materials. The process was determined from the variation of X-ray diffraction patterns and that of dilatometric dimensional change with heating temperatures.
    If the materials excluding SiO2 were mixed, Pb(Ti⋅Zr)O3 was synthesized, passing through formations both of PbTiO3 and PbZrO3. However, when the materials including SiO2 were mixed, the PbZrO3 formation was suppressed, accompanying by a decrease of Pb(Ti⋅Zr)O3 formation temperature.
    The difference seems to be caused by the appearance of a liquid phase formed by the co-existence of SiO2 and PbO, which occurs during the Pb(Ti⋅Zr)O3 formation process. Reaction observed at the contact surface of two green compacts, consisting of SiO2-PbO as well as of Pb(Ti⋅Zr)O3, was in line with the assumption.
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  • [in Japanese], [in Japanese], [in Japanese]
    1973 Volume 20 Issue 5 Pages 161-166
    Published: October 25, 1973
    Released on J-STAGE: May 22, 2009
    JOURNAL FREE ACCESS
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