粉体および粉末冶金
Online ISSN : 1880-9014
Print ISSN : 0532-8799
ISSN-L : 0532-8799
28 巻, 3 号
選択された号の論文の6件中1~6を表示しています
  • 鳥居 道寛
    1981 年 28 巻 3 号 p. 83-89
    発行日: 1981/04/25
    公開日: 2009/05/22
    ジャーナル フリー
  • 武川 淳二郎, 増田 良道
    1981 年 28 巻 3 号 p. 90-94
    発行日: 1981/04/25
    公開日: 2009/05/22
    ジャーナル フリー
    The yield criteria for green compacts of iron and copper powders were determined by means of the uniaxial compression and the triaxial compression tests. In the triaxial test under the condition, preventing the increase in the density of the compacts by the hydrostatic confining pressure, the decrease in the apparent Young's modulus and a large plastic deformation of the compacts with the increase in the confined pressure were observed. The yield-loci for the compacts are of a type in which the second invariant of the stress deviator decreases with the increase in the mean stress, and which is consistent with the compressive behavior of metal powder compacts.
    The experimentally determined yield-loci for the copper compacts agreed very closely with those theoretically calculated by R. J. Green.
  • 高粘度潤滑油を用いた場合
    河野 通, 西野 良夫
    1981 年 28 巻 3 号 p. 95-100
    発行日: 1981/04/25
    公開日: 2009/05/22
    ジャーナル フリー
    Using the lubricant oil with relatively high viscosity, the lubrication mechanism of oil impregnated sintered bearings was discussed in a region of lighter load and higher speed revolution (P;2-6kg/cm2, N;4, 000-24, 000rpm, V;100-600m/min) comparing with ordinary running conditions.
    In the running conditions above mentioned, even sintered bearings can be driven under hydrodynamic lubrication after achieving a sufficient "geometrical conformity" of high speed revolutions (over than about 20, 000rpm). In the region like these, therefore, we cannot conventionally evaluate the degree of severeness of running condition for sintered bearings by the PV value.
    It was found that a linearity exists between the bearing temperature and PVμ which is proportional to the energy produced on the sliding surface. It is to be noted that the linearity relationship is valid regardless of the type of lubrication, i.e. regardless of whether it is hydrodynamic or boundary.
  • 低粘度潤滑油を用いた場合
    河野 通, 西野 良夫
    1981 年 28 巻 3 号 p. 101-104
    発行日: 1981/04/25
    公開日: 2009/05/22
    ジャーナル フリー
    Using the lubricant oil with relatively low viscosity, the lubrication mechanism of oil impregnated sintered bearings was discussed in the same region as the former experiment (1st Report).
    It was found that the aspect of lubrication is similar to that of the former experiment with relatively high viscosity oil, i.e. through the boundary state at low speed revolution, the bearing can be driven under hydrodynamic state at about 24, 000 rpm. In the former experiment, it was found that the bearing can be driven under hydrodynamic state at about 20, 000 rpm. This difference is caused by the difference of the thickness of lubricant oil film due to the different viscosity.
    In the region of low speed revolution through the high speed one, essential features of boundary lubrication of the sintered bearing were recognized. This is caused by the pressure drop of the lubricant oil film on the sliding surface because of the leakage of the pressure into the pores, although the absolute values of the friction coefficient are relatively small. Therefore, in the region as this experiment, one cannot discuss the lubrication mechanism by the values of the friction coefficient.
  • その顕出方法
    沖 幸男, 庄司 啓一郎
    1981 年 28 巻 3 号 p. 105-107
    発行日: 1981/04/25
    公開日: 2009/05/22
    ジャーナル フリー
    A study has been made on the polishing method to reveal real pore structure in sintered steel metallographic specimens.
    A fractional part of pore was observed in the surface when it was examined as polished state, but after several cycles of re-etching and lightly repolishing, real pore structure was revealed.
    The morphology of the pore structure was not smeared by this method.
  • 林 宏爾, 鈴木 寿
    1981 年 28 巻 3 号 p. 108-109
    発行日: 1981/04/25
    公開日: 2009/05/22
    ジャーナル フリー
    The effect of ruthenium addition (up to 0.4%) on the basic properties of WC-10%Co and WC-33%β-12%Co alloys was studied. The properties of these alloys such as transverse-rupture strength and loaddeflection curves, hardness, and cutting performance (at temperatures below 1273K), were almost not affected by the ruthenium addition, though it was observed that the carbide grain size of WC-Co alloy was somewhat reduced.
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