粉体および粉末冶金
Online ISSN : 1880-9014
Print ISSN : 0532-8799
ISSN-L : 0532-8799
8 巻, 3 号
選択された号の論文の3件中1~3を表示しています
  • 明石 雅夫
    1961 年 8 巻 3 号 p. 101-112
    発行日: 1961/06/25
    公開日: 2009/05/22
    ジャーナル フリー
    The ferrites which have a little excess of iron are relatively good-conducting, so far as the raw materials are extremely pure. When CaO, or SiO2 is added to the ferrites the resistivity is increased to some extent. When CaO and SiO2 are properly coexistent in ferrites the resistivity can be further increased, two maxima being found at the different ratio of the contents, one at the lower concentration of SiO2, the other at the higher. It was found that the effect of impurities was different not only by the kind of ferrite tested, but also by firing temperature and atmosphere. The combinations BaO and SiO2, SrO and SiO2, instead of CaO and SiO2, have been also studied. The experimental results will be discussed, in details, in Part II.
  • 田村 皖司
    1961 年 8 巻 3 号 p. 113-120
    発行日: 1961/06/25
    公開日: 2009/12/04
    ジャーナル フリー
    Corrosion tests of an electric heat element chiefly composed of MoSi 2 in various gases and mechanical tests of that in room and high temperature were studied.
    Results were summerized as follows :
    (1) Results of oxidizing test in the air at various temperatures were as follows ;
    0.0001 g/cm2 at 1200°C for 1000 hrs,
    0.0015 g/cm2 at 1300°C for 360 hrs,
    0.0014 g/cm2 at 1400°C for 96 hrs,
    (2) Results of corrosion test in various gases at 1200°C were as follows ;
    0.0004 g/cm2 / day in H2 gas,
    0.0003 g/cm2 / day in N2 gas,
    0.0005 g/cm2 / day in NH3 gas,
    0.0010 g/cm2 / day in CO2 gas,
    0.0001 g/cm2 / day in vacuum at 1600°C.
    (3) Results of mechanical test in room temperature were as follows ;
    Tensile strength 15.4 kg/mm2
    Commpressive strength 12.5 kg/mm2
    Modulus of rupture 16.1 kg/mm2
    (4) Modulus of rupture in high temperature was decreased as the atmospheric tempera-ture was increased ; for example, when the latter was increased from room tempera-ture to 1250°C, the former decreased from 16.1kg/mm2 to 9.5.
    (5) Tensile strength at 1600°C was lkg/mm2.
    (6) Bending creep at 1200°C were as follows ;
    1.40 mm at 4 kg/mm2 testing load,
    0.42 mm at 1 kg/mm2 testing load
  • 柄沢 忠義
    1961 年 8 巻 3 号 p. 121-128
    発行日: 1961/06/25
    公開日: 2009/05/22
    ジャーナル フリー
    Industrialization of ferrite core had been attained 25 years ago in this country. The ferrite industry already developed to higher level, both in economical and technical fields, has been a vital element to modern electronics industry. This rapidly growing industry requires ferromagnetic oxide substance of high performance characteristics but it has been very difficult to satisfy such requirement on the initial phase. The material available at that time was those having on magnetic. changes in characteristics ; it is called non-magnetic after-effect substance. This research consists of a part of the experiment report describing the results of a study to resolve the above-mentioned problem. In our research the subject is resolved from a chemical standpoint, therefore, a relation to theory of vacancy in the physical term shall be adjusted in the future in connection with the aforesaid standpoint.
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