Journal of the Japan Institute of Metals and Materials
Online ISSN : 1880-6880
Print ISSN : 0021-4876
ISSN-L : 0021-4876
Volume 31 , Issue 5
Showing 1-20 articles out of 20 articles from the selected issue
  • Ishi Miura, Hisao Honma
    1967 Volume 31 Issue 5 Pages 607-610
    Published: 1967
    Released: April 04, 2008
    JOURNALS FREE ACCESS
    In the present study, tensile and creep tests were carried out on aluminum composites containing continuous or discontinuous tungsten fiber at high temperatures up to 545°C. The specimens containing continuous tungsten fiber (10 vol% and 20 vol%) showed very large values of tensile strength at 300°C and 500°C, however the specific strengthening effect of the discontinuous-tungsten-fiber-reinforced aluminum composites were considerably smaller than that of the fiber itself.
    The minimum creep rate of the composite containing 20 vol% continuous tungsten fiber was estimated at about 10−4∼10−5%/hr under a load of 6.06 kg/mm2 at 350°C, and the minimum creep rate-temperature curves on the discontinuous fiber were determined under a load of 1.43∼3.05 kg/mm2. By these results, for example, the minimum creep rate for the matrix was 6.0×10−2%/hr under a load of 2.00 kg/mm2 at 350°C, however the minimum creep rate for the composite containing 15 vol% discontinuous tungsten fiber (diameter=25 μ) was 1.4×10−3%/hr under the same condition.
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  • Sakae Takeuchi, Kenji Suzuki
    1967 Volume 31 Issue 5 Pages 611-617
    Published: 1967
    Released: April 04, 2008
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    The measurement of the density and of the lattice parameter was performed over a wide range of composition of TiO and VO phases, and also by the neutron diffraction the position of oxygen ions in their lattices as well as the relative intensity of diffraction lines was determined. From these measurements it has been confirmed that the phases are hormogeneous in the range of TiO0.82-TiO1.23 or VO0.81-VO1.20 and have the NaCl type lattice structure with a large concentration of the vacant lattice sites in both of the metal ion and oxygen ion sublattices. The lattice parameters of these phases are very small in comparison with those of the 3d-transition metal monoxides such as FeO or NiO and are rather close to that of the metallic titanium and vanadium. It is predicted that the existence of such a large amount of vacancies which account for about 15∼20% of the lattice point produce a sort of metallic bonding through overlapping the 3d-orbitals by the reduction of lattice parameter, thus leading the crystal to a state of lower internal energy. Therefore, to attain the state of the lower energy, the occurrence of a large amount of the Schottky pair of vacancies is required in addition to the lattice vacancies whose concentration corresponds to the deviation from the stoichiometric composition. The gain in the internal energy of crystal due to the Schottky pair defect was calculated as a function of the composition and the relations between the vacancy concentration and composition were deduced in good agreement with the observed values for TiO and VO phases. The energy gain due to the formation of the Schottky pair defect was estimated to be about −1 eV at the stoichiometric composition and the estimated fraction of the pair of vacancy produced by thermal agitation was less than 1% even at a high temperature near 2000°K. These results explain the fact that the observed values of the vacancy concentration under various conditions of heat treatment are in agreement within 1%.
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  • Akira Moriyama
    1967 Volume 31 Issue 5 Pages 617-624
    Published: 1967
    Released: April 04, 2008
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    Calculating method of design of the continuous multi-stage fluidized-bed-reactor for non-catalytic reaction was studied.
    When the rate equation could be expressed as a product of the driving force of solid and gaseous phases, theoretical equations to calculate the average driving forces of both phases at each stage of the reactor were derived on the basis of the probability density function of the fractional degree of reaction for solid.
    The two-phase (B·E-type) and homogeneous-phase theories of mathematical models of fluidization, and the gaseous flows contacting with solid particles of piston flow, complete mixing and incomplete mixing, were considered, respectively.
    The mean driving forces of the gaseous reactant are graphically presented.
    A graphical calculation of design can be conducted in principle by using the reaction rate curves and the operating lines. With regard to single-, two- and three-stage reactors, illustrative calculations are shown.
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  • Hiroshi Kojima, Michitoshi Hirata, Teisaku Suzuki, Ryoji Shibata
    1967 Volume 31 Issue 5 Pages 624-630
    Published: 1967
    Released: April 04, 2008
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    The degree of orientation, f and f′, for anisotropic barium ferrite sintered at 800°∼1300°C were determined from X-ray powder patterns following the procedures of Lotgering and Gillam et al. Comparing their relationship to the magnetic properties, it was proved in the scope of the present experiment that the correction of Lotgering’s f values after Gillam et al. did not give a practical improvement and Lotgering’s method is reasonably applicable to the industrial inspection. Br\varparallelBs and Br\varparallel⁄(Br\varparallel+Br) had the closest relationship to the degree of orientation among various magnetic properties, where Br\varparallel and Br indicate the residual inductions parallel and perpendicular, respectively, to the magnetic field applied during the pressing process.
    Besides these ratios, the fullness factor of the B-H curve and Br were measured, and it was found that they increased monotonically with the increase of f or f′. On the other hand, the fullness factor of the I-H curve and (BH)max show maxima in the neighbourhood of f=50%.
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  • Tohei Ototani, Yasuhiro Morooka, Yasuzi Kataura
    1967 Volume 31 Issue 5 Pages 630-634
    Published: 1967
    Released: April 04, 2008
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    The process of graphite precipitation in hypereutectoid steels containing 1.5 to 1.7%C has been investigated by thermal analysis, dilatometric measurement and microstructural observation of water-quenched specimens. The results may be summarized as follows: (1) Any change due to graphite precipitation has not been ascertained by means of thermal analysis. The increased Si contents due to Fe-Ca alloy addition rises in Ar1 transformation more than that found in untreated steels. (2) In the dilatometric measurement the graphite precipitation occurs remarkably in the range of the Agr to the A1 transformation. However, if the amount of Fe-Ca alloy added increased, graphitization was also confirmed slightly above the Ac1 transformation in the process of heating and then showed ferrite formation under the Ar1 transformation in the process of cooling. The shape of the separated graphite by reheating was no longer spheroidal, but became a massive state.
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  • Tohei Ototani, Yasuhiro Morooka, Yasuzi Kataura
    1967 Volume 31 Issue 5 Pages 634-640
    Published: 1967
    Released: April 04, 2008
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    The effect of calcium on the graphite precipitation from the γ phase of the hypereutectoid steel has been examined by a new apparatus for the measurement of solidifying contraction. It has been ascertained that the graphite precipitation in the solidifying process occurred over a range from the vicinity of the saturation curve ES′ of the γ phase (Agr transformation) to the A1 transformation and graphitization was most remarkably near the A1 transformation. A large amount of metallic Ca or Fe-Ca alloy addition greatly affected the solidifying contraction curve, leading to a considerable expansion due to ferrite segregation near the A1 transformation. In this case the rise of the A1 transformation was not observed, although Si contents increased. The addition of Fe-Ca alloy as the graphitizing agent increased the amount of residual calcium more than that determined by metallic Ca.
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  • Kazuo Saito, Keiichi Iida, Ryoji Watanabe
    1967 Volume 31 Issue 5 Pages 641-646
    Published: 1967
    Released: April 04, 2008
    JOURNALS FREE ACCESS
    It is one of the most characteristic behaviors of Cu-4 wt%Ti alloy that a sharp decrease in electrical resistivity and an increase in mechanical strength are observed at the initial stage of ageing. The precipitation sequence from the supersaturated solid solution of Cu-Ti alloy is thought to be: modulated structure→intermediate phase (face centered tetragonal, ca=0.98)→stable precipitate, Cu3Ti.
    The decrease in electrical resistivity is discussed according to Kolomets’ theory which calculates residual resistivity on the assumption of a periodical distribution of solute concentration. The increase in strength, which is expected form the modulated structure, is found to be due to the internal strain hardening mechanism originally suggested by Mott-Nabarro.
    An intermediate phase sustains both electrical and mechanical properties of this alloy. The grain boundary reaction type or the Widmanstätten type of precipitate Cu3Ti, however, leads to softening.
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  • Koji Yuasa, Shigeyasu Koda
    1967 Volume 31 Issue 5 Pages 646-652
    Published: 1967
    Released: April 04, 2008
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    Recrystallization of polycrystalline electrolytic iron which was vacum-melted, cold rolled by 80% and annealed at 550°C has been studied by means of transmission electron microscopy, selected-area electron diffraction and X-ray diffraction. Recrystallization nucleates mostly within a usual cell structure. It is reasonable to conclude that recrystallized grains are formed from subgrains which have been formed by polygonization of cell structure. Formation of small recrystallized grains in the early stage of recrystallization can be explained by the subgrain coalescence model proposed by Hu. After the recrystallized grains develop to a certain size, they would grow by grain boundary migration. The crystallographic orientation of the recrystallized grains in the early stage of recrystallization has a tendency to be nearly the same as that of the deformed matrix which surrounds the recrystallized grains. The orientation of the recrystallized grains in the early stage of recrystallization has a tendency to concentrate in the orientation which has the ⟨111⟩ axis normal to the rolling plane and the orientation which has the (100) plane in the rolling plane and the ⟨110⟩ axis parallel to the rolling direction. The change of the rolling texture during the annealing process seems to occur not due to the nucleation of recrystallized grains with a different orientation from the deformed matrix, but due to the growth process by grain boundary migration of the recrystallized grains which have already been formed.
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  • Shigeo Zaima, Osamu Horiuchi
    1967 Volume 31 Issue 5 Pages 652-657
    Published: 1967
    Released: April 04, 2008
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    It is well known that the machinability of brass improves greatly by adding lead to brass, but it seems that the cause is yet to solved completely. So, the deformation in chip formation in the case of cutting of leaded brass is investigated and the cutting mechanism is discussed in relation to the chip friction on tool face and the chip form obtained, in order to make clear the adding effect of lead on the machinability. As the leaded brass is ordinarily belong to 6/4 brass having a complex (α+β) structure, the 7/3 brass containing 0∼3% lead is prepared. The low speed orthogonal cutting test (cutting speed: 100 mm/min, depth of cut: 0.2 mm) is conducted to discuss on the cutting resistance, the friction between the tool face and the chip, the chip formation and others. According to the results, it is confirmed that the cutting resistance, the contact length of the tool face to the chip, the friction coefficient on the tool face and others decrease and the shear angle increases, and then it is found that the lead in brasss preads itself and acts as a lubricant on the contact surface between tool and chip.
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  • Shigeo Horiuchi, Tadatsune Okubo, Isao Gokyu
    1967 Volume 31 Issue 5 Pages 658-664
    Published: 1967
    Released: April 04, 2008
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    The recrystallization process in 7-3 brass cold rolled by 93% was examined by using an electron microscope. The orientation of the recrystallized grains 1 to 3 μ in diameter, formed at the initial stage of recrystallization, was statistically at random. It can be said, therefore, that the primary recrystallization texture whose major component is {225}⟨734⟩ is formed due to the oriented growth mechanism.
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  • Masami Yajima, Mitsuru Ishii
    1967 Volume 31 Issue 5 Pages 664-668
    Published: 1967
    Released: April 04, 2008
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    Tensile properties of Nb-Zr solid solution alloys composed of the retained high-temperature β phase were investigated at temperatures from −196°C to +800°C. The room-temperature yield stress increases linearly with the zirconium content up to 15 at% and it reaches a maximum value of about 100 kg/mm2 at 42 at%Zr. The mechanical behavior of Nb-15 at%Zr alloy was found to be similar to that of pure niobium, but the alloys with higher zirconium content, e.g. 26 and 42 at%, showed a different behavior from pure niobium. Nb-26 or 42 at%Zr alloy does not show a sharp yield drop. The work hardening rate of the same alloy is smaller than that of niobium, being insensitive to the test temperature. Nb-26 or 42 at%Zr undergoes twin deformation below −72°C and a distinct serration appears in its load vs. elongation curves. The low-temperature flow stress of these alloys increases significantly with decreasing temperature. The temperature dependence of flow stress of Nb-15 at%Zr is similar to that of niobium whereas that of Nb-26 or 42 at%Zr alloy is small compared with that of Nb and Nb-15 at%Zr alloy. At temperatures above room temperature, the flow stress of niobium is insensitive to the test temperature and keeps constant up to 600°C, while the flow stress of alloys decreases with temperature and becomes constant at some higher temperatures. The higher the alloy content, the greater is the decreasing rate. The temperature at which the flow stress becomes insinsitive to temperature also rises with alloy content. Elongation at room temperature decreases with zirconium content. But at high temperature, the effect of zirconium content disappears due to the large decrease of elongation of niobium. At temperatures above 600°C the elongation of niobium increases with temperature, while that of alloys continues to decrease with temperature.
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  • Seiichi Karashima, Hiroshi Oikawa, Tsugio Ogura
    1967 Volume 31 Issue 5 Pages 669-674
    Published: 1967
    Released: April 04, 2008
    JOURNALS FREE ACCESS
    The substructure formation around fatigue cracks in α-brass, copper and aluminium was studied by means of X-ray microbeam technique, in order to make clear the relation between substructure and fatigue crack propagation.
    The results obtained were as follows: (1) There exist plastic zones in the vicinity of fatigue cracks in all the cases. (2) In α-brass subgrains were formed only with in the plastic zone, whereas in copper and aluminium grains were divided into smaller subgrains in the zone than in the matrix. (3) The substructure became pronounced as the stacking fault energy increased. (4) In aluminium, fatigue cracks propagated more quickly in the specimen with a more developed substructure.
    From the experimental results, it is concluded that the substructure formation is not only an incidental phenomenon but plays an important role in the mechanism of fatigue crack propagation.
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  • Seiichi Karashima, Hiroshi Oikawa, Tsugio Ogura
    1967 Volume 31 Issue 5 Pages 674-678
    Published: 1967
    Released: April 04, 2008
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    In order to study a more detailed mechanism of fatigue crack propagation, dislocation structures in the vicinity of fatigue cracks of thin-foil α-brass, copper and aluminium have been observed by transmission electron microscopy.
    It has been found that well-developed substructures are formed in the vicinity of fatigue cracks, subgrain sizes of α-brass, copper and aluminium are 2∼3 μ, 1∼2 μ and 2∼4 μ, respectively, and more distinct substructures are formed in order of the stacking fault energies. Moreover, direct evidence, which suggest that fatigue cracks might propagate through sub-boundaries, is obtained on aluminium.
    In conclusion, the results of electron microscopic observations are in good agreement with those of X-ray examination which have been reported in the previous paper, suggesting that substructure formation plays an important role in the propagation of fatigue cracks.
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  • Ohiko Kammori, Naoharu Yamaguchi, Hideo Kanno
    1967 Volume 31 Issue 5 Pages 679-683
    Published: 1967
    Released: April 04, 2008
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    A mass spectrometer was applied for vacuum fusion analysis of micro-amounts of gases in iron and steel produced by vacuum melting and vacuum casting. The gases extracted from the metal specimen in a vacuum fusion furnace were collected directly in the gas reservoir through a mercury diffusion pump, and the individual constituents were determined by the mass spectrometer (Gas Detector, ATLAS-WERKE AG.). The limits of detection for this apparatus were 0.07 μg of oxygen, 0.1 μg of nitrogen and 0.005 μg of hydrogen. The analysis took approximately 30 minutes. From the extraction curve with vacuum fusion it was proved to be extracted gases from iron and steel within 2 minutes.
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  • Kiyoshi Takayanagi, Natoshi Takezaki, Akira Negishi
    1967 Volume 31 Issue 5 Pages 684-690
    Published: 1967
    Released: April 04, 2008
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    The effects of sintering temperature and time upon the thermoelectric properties of elements made from Bi2Te3 and its alloys by a powder metallurgical method have been studied and the mechanism of their property variations investigated.
    Pressed elements from Bi2Te3 and its alloys were sintered in evacuated glass ampoules at various temperatures ranging from room temperature to those just below melting points, and their thermoelectric power α and specific resistivity ρ were measured. Besides, the Hall coefficient of some samples was measured, from which the variations in carrier concentration and carrier mobility with sintering temperature were calculated.
    The result of experiments showed that properties changed roughly over three stages, that is, on sintering at temperature below 200°C at which cohesion of particles did not begin, a decrease in donors was observed. Between 200°C and 450°C, with cohesion of particles, a remarkable increase in donors was revealed. Then, above 450°C, the introduction of acceptors was observed. The increase in donors below 200°C relates to the extinction of lattice defects that occur at the time of powder production and compacting, and the activation energy for such extinction was found to be 1.2 eV. The increase in donors between 200°C and 450°C with increase in temperature is due to secondary defects that occur during cohesion of particles. In samples of low hole concentrations, the change from the P type to the N type conduction took place. The activation energy for the change was found to be 2.2 eV. From measurements of the weight loss during sintering, it has been clarified that the introduction of acceptors relates to the evaporation of Te.
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  • Masao Ibaraki, Taira Okamoto, Hiroshi Matsumoto
    1967 Volume 31 Issue 5 Pages 690-696
    Published: 1967
    Released: April 04, 2008
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    The eutectic structure of iron-carbon and iron-carbon-silicon alloys of nearly eutectic composition has been studied in terms of the freezing rate, temperature gradient and third elements such as silicon and sulfur. The alloys frozen vertically over a range of freezing rates from 0.04 to 4.50 cm/hr consisted entirely of the graphite-austenite eutectic. The relationship between the inter-graphite spacing λ and the freezing rate R is represented by the formula λ∝Rn and n has a value of 0. 46∼0.48 for iron-carbon and iron-carbon-silicon alloys. A slight addition of 0.015% sulfur into the alloys decreases the value of n to 0.30∼0.32 and increases the inter-graphite spacing. From a theoretical consideration, the inter-graphite spacing depends on the interplay between the diffusion in austenite and the formation of the austenite/liquid interface. The increasing content of the third element, such as sulfur, which reduces the austenite/liquid interfacial energy deepens the groove developed in the center of austenite between graphite flakes and decreases the amount of carbon supplied in autsenite per unit area of the austenite/liquid interface during freezing. This has a tendency to increase the inter-graphite spacing. The effects of temperature gradient and silicon on the inter-graphite spacing are not significant as compared with those of the freezing rate and sulfur.
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  • Mikio Yamamoto, Takurô Nakamichi, Norio Yokoyama, Norikuni Hayas ...
    1967 Volume 31 Issue 5 Pages 696-701
    Published: 1967
    Released: April 04, 2008
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    The strain gauge factor and the electrical resistivity as a function of composition have been investigated in the cold-worked state of Fe-Ni-Cr alloys containing 35 wt%Ni and 0∼20 wt%Cr, in order to clarify the origin of the high strain gauge factor of Iso-elastic alloy with the composition of 52 wt%Fe, 36 wt%Ni, 8 wt%Cr and 4 wt%(Mn+Mo). The strain gauge factor starts from the value of 2.37 at the Invar alloy (0%Cr) increases with increasing chromium content, reaches a maximum of 3.65 at 7.23 wt%Cr, and then decreases to a final value of 2.55 at 18.46 wt%Cr. Corresponding to this composition dependence of the strain gauge factor, the curves of the electrical resistivity vs. chromium content at room temperature and of its average temperature coefficient between the liquid air and room temperatures show bends at about 7 wt%Cr; they changes very rapidly below about 7 wt%Cr, beyond which they remain almost constant. This fact suggests that the largest value of the strain gauge factor at 7.23 wt%Cr has a close connection with the mode of the temperature variation of the electrical resistivity.
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  • Mikio Yamamoto, Takurô Nakamichi, Norio Yokoyama
    1967 Volume 31 Issue 5 Pages 702-707
    Published: 1967
    Released: April 04, 2008
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    In succession to the measurements of the strain gauge factors and electrical resistivities reported in the preceding paper, the saturation magnetization, Curie temperature and magnetostriction have been measured in the cold-worked state of iron-nickel-chromium alloys containing 35 wt%Ni and 0∼20 wt%Cr. The Curie temperature does not show any substantial change with the chromium content up to about 7%, beyond which it shows a rapid decrease. Contrary to this, the saturation magnetization decreases almost linearly with increasing chromium content. The forced magnetostriction coefficient decreases appreciably with increasing chromium content up to about 7%Cr, then remains almost constant up to 14.3 wt%Cr, and finally drops to zero at 18.46%Cr, where the alloy is paramagnetic at room temperature. Whereas, the saturation magnetostriction shows a monotonous decrease with increasing chromium content. From the above finding the largest value of the strain gauge factor obtained at about 7%Cr appears to be related to the composition dependence of the Curie temperature, forced magnetostriction coefficient and electrical resistivity as described in the preceding paper. It is shown that the high strain gauge factors in this ternary alloy system can be interpreted thermodynamically.
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  • Kaizo Monma, Hajime Suto, Yoshikazu Nakamura
    1967 Volume 31 Issue 5 Pages 708-709
    Published: 1967
    Released: April 04, 2008
    JOURNALS FREE ACCESS
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  • Yunoshin Imai, Takeo Murata
    1967 Volume 31 Issue 5 Pages 709-710
    Published: 1967
    Released: April 04, 2008
    JOURNALS FREE ACCESS
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