巻号一覧
22 巻, 4 号
選択された号の論文の4件中1～4を表示しています
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On the Basis of Measurement of Linear InterceptsH.E. Rose1975 年 22 巻 4 号 p. 121-130
発行日: 1975/06/25
公開日: 2009/05/22
ジャーナル フリーIn this paper the problem of the evaluation of the grain-size distribution of a spherical material embedded in a matrix is studied and a solution, based upon the measured distribution of the intercepts upon a random line cut off by the particles, is developed.
There are no limitations on the method, with respect to the type of particle-size distribution involved and, in theory, the grain size distribution may be established to any desired degree of accuracy by the use of a conversion table.
Conversion tables, sufficiently comprehensive for many practical purposes, are provided and the necessary calculations involve only a knowledge of multiplication and addition.
The work suggests that the method based upon the measurement of intercepts is experimentally simpler than is the case when the diameters of the circular intersection figures are measured. Furthermore, since the conversion tables contain fewer terms than is the case for measurements based upon diameters, the labour of application is much less than in the method based upon the measurement of the diameters of the intersection figures.抄録全体を表示PDF形式でダウンロード (407K) -
鈴木 寿, 林 宏爾, 寺田 修1975 年 22 巻 4 号 p. 131-135
発行日: 1975/06/25
公開日: 2009/05/22
ジャーナル フリーA peculiar structure was found to develop around Vickers hardness indentation in TiC base cermets, whereas it has never developed in WC base cemented carbides. Therefore, in this report, the above structure was investigated at room temperature using various cermets with various Ni, C and Mo contents and carbide grain size.
As the result, it was made clear that the structure was mainly associated with trans- and intergranular cracks of carbide under the heavy stress generated by Vickers impression, so that it was considerably influenced by various factors as shown above. The fractured structure was considered to be due to lower strength and plasticity of titanium carbide solid solution than those of WC. These results would be a help for understanding the mechanical properties of cermets.抄録全体を表示PDF形式でダウンロード (6008K) -
紺田 功, 大北 熊雄, 田畠 良和1975 年 22 巻 4 号 p. 136-140
発行日: 1975/06/25
公開日: 2009/12/04
ジャーナル フリーMedium and low-density sintered iron compacts usually have many pores, which size and shape are various. In the present paper the influence of these pores upon the fatigue strength has been investigated.
For the fatigue fracture of the medium and low-density sintered iron compacts, the following conclusions were obtained from microscopic observations.
1) Cracks generate from the pores with sharp edges and from the pseudo boundaries, without generation of slip bands in a crystal grain.
2) These cracks generate later than in the case with high density sintered iron compacts and once the cracks generate, they grow rapidly.
This tendency becomes stronger, in the case of fatigue fracture under low stress.抄録全体を表示PDF形式でダウンロード (4194K) -
小原 嗣朗, 立沢 清彦1975 年 22 巻 4 号 p. 141-146
発行日: 1975/06/25
公開日: 2009/12/04
ジャーナル フリーThe relationship between the tensile strength and porosity in sintered compacts has been investigated by using electrolytic iron powders. It was shown that the variation in the tensile strength with the porosity (or density) could be expressed separately in three stages, that is, the low density region, the middle density region, and the high density region. The relations of tensile strength and porosity in those three regions can be represented by the following forms.
For the low density region,
S=S'0-k1P (P1<P≤PO)
where S is the tensile strength, P, the porosity, PO, the green porosity, and S'0, k1 and P1, empirical constants. For the middle density region,
S=S'0 exp(-bP) (P2<P≤P1)
where S is the tensile strength, P, the porosity, and SO, b, P1 and P2, empirical constants. For the high density region,
S=(S s+k 2G-1/2)exp(-bP) (P≤P 2)
where S is the tensile strength, G, the grain size, P, the porosity, and S8, K2, b and P2, empirical constants, if the grain size can be represented as a function of porosity,
S=(Ss+k3Pa)exp(-bP) (P≤P2)
where S is the tensile strength, P, the porosity, and S8 k3, a, b and P2, empirical constants.
The empirical constants contained in the above forms were determined by the experimental results. Then, the following forms representing the relations of tensile strength and porosity for the sintered electrolytic iron powder were obtained. When the compressing pressure is 4 t/cm2, for the low density region,
S=132-495P [kg/mm2] (0.23<P≤0.27).
For the middle density region,
S=43.0 exp(-4.4P) [kg/mm2] (0.085<P≤0.23).
For the high density region,
S=(29.5+1.05G-1/2) exp(-4.4P) [kg/mm2] (P≤0.085)
where C is in mm, and
S=(29.5+62.5P0.62) exp(-4.4P) [kg/mm2] (P≤0.085).抄録全体を表示PDF形式でダウンロード (389K)
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