材料
Online ISSN : 1880-7488
Print ISSN : 0514-5163
ISSN-L : 0514-5163
20 巻 , 215 号
選択された号の論文の13件中1~13を表示しています
  • 沢岡 昭, 斎藤 進六
    1971 年 20 巻 215 号 p. 912-917
    発行日: 1971/08/15
    公開日: 2009/06/03
    ジャーナル フリー
  • 西原 正夫, 藤田 達, 山口 喜弘, 松下 富春, 野口 昌孝
    1971 年 20 巻 215 号 p. 918-923
    発行日: 1971/08/15
    公開日: 2009/06/03
    ジャーナル フリー
    Hereunder is presented a report of construction of a 500ton hydrostatic extrusion press planned for industrial expediency. The press has maximum working pressure 15000kg/cm2, and being composed of two container systems, billet container and pressure container, is especially fit to extrude very long billets. The press was used in an experiment, of which the results are as follows.
    At high extrusion speed continuous hydrodynamic lubrication is maintained, which lowers extrusion pressure. At large extrusion ratio, the high extrusion speed softens the products by reason of high temperature generated during the extrusion.
  • 岸上 守孝, 江上 清一, 松本 圭司, 服部 一郎
    1971 年 20 巻 215 号 p. 924-930
    発行日: 1971/08/15
    公開日: 2009/06/03
    ジャーナル フリー
    The hydrostatic packing characeristics on several kinds of powders, i.e. electrolytic copper, electrolytic iron, reduced iron, atomized iron, molybdenum and tungsten, are studied.
    Both Kawakita's and Athy's equations that are used as the relations for the process of uniaxial die pressing have been examined to see whether they are applicable to the hydrostatic packing. Consequently, the process of hydrostatic compacting appears to support Kawakita's eq. in low pressure range, and Athy's eq. in high pressure range.
    In Kawakita's eq., the characteristic constant“a”corresponds to initial porosity, and the constant“1/b”appears to relate with the particle strength.
    On all the powders tested, three stages are recognized on the curve of (P/p)·(V-V)/(Vao-V) versus (Vao-V)/(Vao-V), where P is the compacting pressure, p the constant, V-V the volume of residual porosity, Vao-V the volume of initial porosity and Vao-V the volume of loss porosity. To substitute σt/P for the parameter (P/p)·(V-V)/(Vao-V) in the relation, the shape of the curve is made similer to that described above, where σt is the tensile strenght of compacts. These three stages appear to correspond to the different packing mechanismus, respectively.
  • 小坂田 宏造, 白石 紀明, 大矢根 守哉
    1971 年 20 巻 215 号 p. 931-936
    発行日: 1971/08/15
    公開日: 2009/06/03
    ジャーナル フリー
    Hereunder is presented a report of hydrostatic extrusion of pure copper performed of commercial stuff at the extrusion ratios from 1.2 to 3.6, inclusive of the die angles from 20°to 90°. The residual stress distribution in it and its Vicker's hardness distribution have also been determined.
    The residual stresses in it have been measured by Sach's method utilizing its drilling and chemical erosion. There have been found to exist, on the surface of the extruded rod, residual tensile stresses in its longitudinal and tangential directions. The longitudinal tensile stress decreases with increasing extrusion ratio. The die angle has little effect on the residual stress distribution at the extrusion ratio of 2.0.
    The hardness is determined as the mean of the values obtained in more than five experiments, and it is found that the value of hardness on the surface is larger than that at the center, and that this tendency becomes marked at low extrusion ratio and or at larger die angles. Theoretical calculation of hardness distribution is carried out assuming a velocity field, which gives a lowest extrusion pressure when upper bound solution is applid. The calculated hardness distribution is in fair agreement with the experimental results except for those at low extrusion ratios.
  • 大森 正信, 吉永 芳豊, 助川 一弥, 丸山 善昭
    1971 年 20 巻 215 号 p. 937-944
    発行日: 1971/08/15
    公開日: 2009/06/03
    ジャーナル フリー
    Hereunder is presented a report of an experimental study in which tests were made, under hydrostatic pressure up to 3000kg/cm2, of three polycrystalline metals, mild steel, 70-30 brass and pure industrial aluminium, with respect both to their tension and torsion, with a view to finding the characteristics in their increase in ductility due to the pressure superimposed on them. Besides these tests a tension test of aluminium crystals of high purity was also carried out under various pressures. The main results of the study are summarized as follows.
    (1) The increase in ductility due to the superimposed pressure is meant, concerning the tensile deformation, by the increase not in uniform elongation but local elongation or in fracture strain, and, concerning the torsional deformation, by the increase in uniform shear strain, leading to the failure along the axis of the specimen.
    (2) When two specimens of one metal were subjected to incipient strain under certain pressure, to be more precise, when one of the specimens was subjected to as large strain as the other, but while the one was processed under atmospheric pressure, the other was processed under high hydrostatic pressure, and when the strain has since been kept on both the specimens under as high pressure as at the beginning until the failure has begun to occur, the larger residual strain has been being presented up to the failure in that specimen which was subjected to the incipient strain under high hydrostatic pressure, than in the other that was processed under atmospheric pressure. These different effects from each other given on the specimens can be considered as suggestive of their origin intrinsically impressed in the structure of these specimens which were differently affected incipiently from each other, i. e. one under atmospheric pressure and the other under hydrostatic pressure. It is noteworthy, on the other hand, however, that there is no such intrinsic difference effected on the specimens in evidence as has been suggested above in the microscopic examination which was conducted for comparative studies of dislocation cell structure of mild steel and of slip line patterns in single crystalline high purity aluminium. These metals were stretched or twisted, each under the respective kind of pressure either atmospheric or hydrostatic. Neither of the specimens presented any difference in the result of its treatment.
    (3) In mild steel its fracture strain increases to the failure due to tension under high hydrostatic pressure. In pure industrial aluminium its shear strain increases to the failure due to torsion under high hydrostatic pressure. It is noteworthy in this connection that the lower the speed of deformation in these metals drops, the higher the rate of increase in the strain in them rises, though it is not known yet how the phenomena are to be accounted for.
  • 久保 勝司
    1971 年 20 巻 215 号 p. 945-951
    発行日: 1971/08/15
    公開日: 2009/06/03
    ジャーナル フリー
    The hydrostatic extrusion of the billet is a new extrusion process differing from the conventional method in utilizing the pressurized liquid and keeping the material in contact with the dies. The practical use of this process involves a serious question concerning how to prevent the stick-slip motion. There are, it is considered, various factors that bring about the stick-slip motion, such as lubricants, extrusion ratios, the materials of the billet and die angles. In the present study the stick-slip motion has been analyzed in terms of these factors using an electromagnetic oscillograph. The results obtained are as follows.
    (I) The temperature of oil film of lubricant formed inside the dies holding the billet plays an important part in causing the stick-slip motion.
    (2) The smaller die angle will render the lubricant to be preventive of the stick-slip motion.
    (3) Large stick-slip motion has always appeared with bulging deformation at the extrusion of brittle materials.
  • 藤城 郁哉, 三井 寿雄, 妹尾 允史, 赤尾 勝
    1971 年 20 巻 215 号 p. 952-955
    発行日: 1971/08/15
    公開日: 2009/06/03
    ジャーナル フリー
    A phase diagram of Al-Si system in the hypoeutectic region at 28kb has been composed. A girdle-type high pressure device was used to press and heat the specimens, and an electric resistance method to detect the phase transitions. The characteristic figures obtained are as follows;
    (1) The melting point of pure Al has been elevated to 840°C at 28kb from 560°C at 0kb giving 6.4°C/kb as for the pressure derivative. The fiqures are very close to the experimental value of Jayaraman and also agrees approximately with a value 5.5°C/kb calculated from the Clausius-Clapeyron's thermodynamical relation.
    (2) The eutectic temperature of this system has been elevated from 577°C at 0kb to 660°C at 28kb giving 3.0°C/kb as for the pressure derivative. This value agrees fairly well with the calculated value 2.5°C kb.
    (3) The solid solubility of Si at the eutectic temperature has been broadened to 7.0 at.% at 28kb from 1.6 at.% at 0kb, This value is comparable to the solubility 8.5 at.% calculated under the assumption of the dilute solid solution model using-5.5×10-24cm3/atom as the change of molar volume per solute atom.
  • 中島 孝慈, 藤城 郁哉, 栗田 康二, 三井 寿雄
    1971 年 20 巻 215 号 p. 956-961
    発行日: 1971/08/15
    公開日: 2009/06/03
    ジャーナル フリー
    Hereunder is presented a brief report of the tensile tests performed under hydrostatic pressure up to 2000kg/cm2 on specimens of zinc single crystals with various orientation. The load-elongation curves and the features of plastic deformation to fracture varied significantly in accordance with the crystal orientation. There was, in the specimen of zinc single crystals, as in the polycrystalline specimen, the critical environmental pressure that turned the brittle manner of the specimen into the ductile. Beyond that critical point the specimen, of which angle φ between the tensile axis and the c-axis of the crystal was nearly 45° or less, varied their deformation pattern to the slip in the basal plane from the cleavage in the same plane.
    In specimens with orientation other than what has been described above, twin, non-basal slip and kink were observed in addition to the basal slip. In these specimens, since the various crystal planes contribute to these deformation process, the load-elongation curves turn out to be the complex ones. There took place abrupt change in their fracture mechanism from the cleavage type to the shear type.
  • 中島 孝慈, 藤城 郁哉, 栗田 康二, 三井 寿雄
    1971 年 20 巻 215 号 p. 962-967
    発行日: 1971/08/15
    公開日: 2009/06/03
    ジャーナル フリー
    In the preceding study the tensile tests were made of the specimens of zinc single crystals with their angle φ larger than 30° of the tensil axis and the c-axis of the crystal under hydrostatic pressure up to 2000kg/cm2.
    In the present study the specimens having the angle φ less than 30° have been subjected to the same experiment.
    The results are summarized as follows:
    (1) The specimen is cleaved on its basal plane when the environmental hydrostatic pressure is below the critical value.
    (2) While the hydrostatic pressure enacts the part of compressive stress component to suppress the breakage of the crystal, the extent to which the breaking stress is enhanced varies diversely with the value of φ, the mode of plastic deformation, and the manner of chucking the specimen.
    (3) No cleavage takes place in the crystal when the environmental pressure exceeds the critical value, and most of the specimens tend to slip on their basal planes. As the angle φ decreases, however, this primary slip is accompanied by such additional deformations as kink, twin and the secondary basal slip within the twin, and a necking is developed in the specimen.
    (4) When the angle φ is extremely low such as less than 5°, the necking is developed without an active slip on the basal plane and the specimen is broken in a shear-type mode.
  • 中川 紀寿, 幡中 憲治, 川辺 秀昭, 山田 朝治
    1971 年 20 巻 215 号 p. 968-974
    発行日: 1971/08/15
    公開日: 2009/06/03
    ジャーナル フリー
    Fatigue deformation studies have been widely undertaken by many investigators, still the fatigue mechanism are not clarified yet. In the present investigation the fatigue deformation and also the fatigue mechanism of annealed polycrystals of pure aluminum (99.99%) have been studied at room temperature and at elevated temperatures of 80°C and 130°C. The deformation behavior of specimens during fatigue was examined by both the replica and the transmission electron microscopy techniques. At the same time the ease of cross slipping at elevated temperatures was taken into consideration.
    The results obtained were as follows:
    (1) At elevated temperature fatigue, the surface of the specimen is deformed more than at room temperature and the cracks propagate in such a way as to link many micro-cracks which are made of the pores.
    (2) Large numbers of dislocation loops were found in the specimen at elevated temperature fatigue. These loops play an important part in forming the cell and they are also closely related to the initiation and the propagation of a crack.
    (3) The cell walls are formed by dislocations which are clustered along low index planes, e. g. {100} and {110}. The cell size was larger at elevated temperature (5 to 9μ) than at room temperature (2 to 4μ).
  • 功刀 雅長, 大田 陸夫, 小川 智司
    1971 年 20 巻 215 号 p. 975-981
    発行日: 1971/08/15
    公開日: 2009/06/03
    ジャーナル フリー
    The conversion of octahedral cobalt (II) into tetrahedral symmetry has been studied in alkali borate glass, i. e., Li2O-B2O3, Na2O-B2O3, K2O-B2O3, with addition of halide by processing absorption spectroscopy in the ranging of wavelength 350-2000 millimicrons. The results of measurement are shown in Fig. 3-Fig. 11. Addition of halide to alkali borate glass intensifies the cobalt (II) absorption and modifies the absorption spectra considerably. In the two kinds of glass 10Na2O·90B2O3 and 20Na2O·80B2O3 (mol. %), with halogen X (X=Cl, Br or I) ingredient, the co-ordination number of cobalt (II) converts the octahedral into the tetrahedral configuration present as CoO6→CoX4. In the glass 30Na2O·70B2O3 the addition of halogen causes decrease in intensity of absorption spectra with increase in halogen concentration as the result of the changing CoO4→CoO6→CoX4. The effect of varying the kind of alkali is negligible. The density of the glass in degree was also determined.
  • 前田 松夫, 日比 貞雄, 吉村 正
    1971 年 20 巻 215 号 p. 982-989
    発行日: 1971/08/15
    公開日: 2009/06/03
    ジャーナル フリー
    There have been several papers hitherto published relating to young's modulus of polymer film filled fragmented glass fibers to the moduli of its constituents. Few of them have, however, taken the orientation distribution of the glass fibers into consideration in calculating the bulk modulus.
    In this paper, the effect of orietation distribution of the glass fiber upon the bulk modulus is first formulated on a basis of the homogeneous stress hypothesis for an aggregate model of concentric structural units consisting of the glass fiber surrounded by the polymer component. Then, the structural unit is corrected so that the normal stress in the fiber varies along the fiber axis.
    The anisotropy of Young's modulus calculated upon the above given model agrees fairly well with that observed for polyethylene and polyester films both filled with glass fibers in a range of volume fractions less than 30%.
  • 岡田 清, 六車 熙, 森田 司郎
    1971 年 20 巻 215 号 p. 990-998
    発行日: 1971/08/15
    公開日: 2009/06/03
    ジャーナル フリー
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