日本金属学会誌
Online ISSN : 1880-6880
Print ISSN : 0021-4876
ISSN-L : 0021-4876
55 巻, 5 号
選択された号の論文の17件中1~17を表示しています
  • 小松 伸也, 池田 勝彦, 杉本 隆史, 亀井 清, 井上 幸一郎
    1991 年 55 巻 5 号 p. 491-496
    発行日: 1991年
    公開日: 2008/04/04
    ジャーナル フリー
    It was investigated whether the negative temperature dependence of resistivity will appear in Ti-Fe alloys of eutectic type, similarly to other β-isomorphous type Ti alloys. With Ti-Fe alloys quenched from 1173 K, X-ray diffraction, optical microscopy, resistivity measurement and hardness test were carried out.
    β phase was retained in the alloys containing more than 4%Fe. Reflections or diffuse scattering of ω phase were not obvious in the alloys containing more than 5%Fe.
    The negative temperature dependence appeared in the Fe concentration range between 5 and 15%. This anomalous temperature depndence can be interpreted by the reversible formation and disappearance of athermal ω phase with cooling and heating below room temperature, similarly to other β-isomorphous type Ti alloys.
    The hardness showed a maximum at 4% and increased again above 10%. This can be explained by the hardening proportional to the amount of the athermal ω phase formed at room temperature and the solution hardening by Fe in the β phase.
    As compared with other β-Ti alloys in terms of the electron/atom ratio (e/a), the resistivity at liquid nitrogen temperature of 6%Fe, 1.9 μΩm, was the largest. The decrease of the resistivity, as in the case of the resistivity ratio ρLNRT, beyond a peak with increasing e/a was the least amount in the Ti-Fe alloys. From these observations, the decrease of the starting temperature for formation of the athermal ω phase per unit e/a was considered to be the smallest in Ti-Fe alloys.
  • 高橋 裕, 坂田 貢三, 石田 洋一
    1991 年 55 巻 5 号 p. 497-506
    発行日: 1991年
    公開日: 2008/04/04
    ジャーナル フリー
    High-voltage electron microscopy investigation have been performed on (001) GaP/GaP1−xAsx grown by the chemical vapor deposition technique. In a continuous-graded specimen, dense and symmetric networks of ⟨110⟩ dislocations (1012 m−2 order) were observed in the graded layer but few dislocations propagated to the upper region, while in a step-graded specimen, inclined dislocations penetrated. The structural difference of dislocations is responsible for the difference in an emitting efficiency. Crystallographical and quantitative analysis of misfit dislocations such as Burger vector, slip plane, interaction and density was carried out in detail.
  • 佐藤 茂夫, 漆原 富士夫, 鈴木 朝夫
    1991 年 55 巻 5 号 p. 507-514
    発行日: 1991年
    公開日: 2008/04/04
    ジャーナル フリー
    Phase decomposition and precipitation in Fe-35 at%Ni-35 at%Mn, Fe-40 at%Ni-40 at%Mn and Fe-45 at%Ni45 at%Mn alloys were Investigated by means of optical and electron microscopy, X-ray diffraction, dilatation, electrical resistivity and hardness measurements.
    Spinodal decomposition in the matrix and cellular precipitation from grain boundary occur about the same time. In the matrix, high Ni and high Mn region changes into an ordered fct phase with progress of the decomposition. In the grain boundary, the primary cell shows a modulated structure and dccomposes to an fcc (or a bcc) phase and an fct phase with progress of aging. As the aging temperature rises, the primary cell becomes a lamellar structure and spinodal decomposition is hardly observed in the matrix. This lamellar structure consists of an fcc phase and an fct phase.
    The composition at which the modulated cellular structure appears is the spinodal region. The composition at which the lamellar cellular structure precipitates is regaded as the miscibility gap.
  • 桑山 健太, 若松 良徳, 下崎 敏唯, 大西 正已
    1991 年 55 巻 5 号 p. 515-520
    発行日: 1991年
    公開日: 2008/04/04
    ジャーナル フリー
    The interdiffusion coefficients were obtained by use of the Au-Pt and Au-α1 (20 at%Pt) diffusion couples annealed in the temperature range between 1243 and 1333 K. The concentration dependence of the coefficients determined with the Au-α1 (20 at%Pt) couple differs from that determined with the Au-Pt couple. The extrapolated values of the coefficients determined with the Au-α1 (20 at%Pt) couple to zero atomic percent of Pt were in good agreement with the impurity diffusitivities of Pt in Au. The array of multiple markers embedded in the Pt part of the Au-Pt couple before diffusion bent to Au-rich side sharp at the α12 phase boundary after diffusion. Both the α1 and α2 phases belong to the same type of the crystal structure (f.c.c.). The bend in this experiment, therefore, indicates that vacancies are created owing to formation of the extra lattice planes at the phase boundary with the same type of the crystal structure.
  • 金 ?, 菅又 信, 金子 純一
    1991 年 55 巻 5 号 p. 521-528
    発行日: 1991年
    公開日: 2008/04/04
    ジャーナル フリー
    Cast and extruded composites of SiC whisker reinforced AZ91 magnesium alloy were fabricated by high pressure infiltration of the alloy melt into preformed whiskers and subsequent hot extrusion. Structures, age hardening behavior and mechanical properties were examined on the obtained composites, and the effect of hot extrusion was discussed. Unidirectional alignment of whiskers was attained by hot extrusion of the cast composites with a sacrifice of appreciable decrease of aspect ratio of whiskers. Such structural changes caused an increase of elastic modulus and a slight decrease of the strengthening effect of whiskers for tensile strength in the extruded composites. At elevated temperatures, lower tensile strength and higher ductility were observed for the extruded composites than for the cast ones. The extruded composites in T6 temper showed much higher specific elastic modulus than titanium alloys or maraging steels, and higher specific tensile strength than high strength aluminum alloys.
  • 亀田 和夫, 山口 勉功
    1991 年 55 巻 5 号 p. 529-535
    発行日: 1991年
    公開日: 2008/04/04
    ジャーナル フリー
    A study of thermodynamic properties of the liquid Te-Tl alloys has been carried out by the galvanic cell of
    (This article is not displayable. Please see full text pdf.)
    \ oindentThe reliable values of E. M. F. were obtained for the alloys.
    Activities of thallium show negative deviations in the wide concentration range and abruptly increase from negative to positive around NTl=0.65-0.70 and show positive deviations from Raoult’s law in the thallium-rich side. Activities of tellurium exhibit negative deviations from Raoult’s law over the whole concentration range. The activities of both components approach the ideal lines with increasing temperature.
    From the features of α functions of thallium for the system, the alloys are not considered as regular solutions.
    It is observed that the anomalous behaviors in Δ\barHTl and Δ\barSTl at the composition of TeTl2 are affected by the stable compound in the liquid state. The minimum values of the heat of mixing for the system are −25.3 kJ/mol at about ΔNTl=0.65.
    In addition, other thermodynamic functions were calculated on the basis of the results obtained.
  • 亀田 和夫, 山口 勉功
    1991 年 55 巻 5 号 p. 536-544
    発行日: 1991年
    公開日: 2008/04/04
    ジャーナル フリー
    The emf measurements of the following galvanic cells have been carried out to determine the standard free energy of formation of Bi2O3 (s) and the thermodynamic quantities of liquid Ag-Bi alloys:
    (This article is not displayable. Please see full text pdf.)
    \ oindentThe standard free energy of formation of Bi2O3 (s) are determined as follows:
    (This article is not displayable. Please see full text pdf.)
    \ oindentThe concentration dependence of activities of bismuth shows a positive moderate deviation from the Raoult’s law. Activities of silver show both positive and negative deviations from Raoult’s law. Our data for bismuth do not agree with the result by Gregorczyk but roughly do well with that by Aldred et al. and Predel et al.
    The order of magnitude of both activities and heats of mixing of IB metals (Cu, Ag and Au)-bismuth binary alloys in the intermediate composition range is approximately the same as that in the Periodic Table (i.e., Cu, Ag and Au). The activities and the heats of mixing of the Au-Bi alloys show small negative deviations and smaller exothermic values, respectively, over the whole concentration range. Such a affinity of Au-Bi alloys may be ascribed to the larger differences in the electronegativities in the gold alloys.
    In addition, the results of both activities and heats of mixing measurements in the liquid binary alloys composed of IB metals and bismuth and those composed of IB metals and other typical normal metals (i.e., Zn, Cd, Al, Ga, In, Sn and Sb etc.,) have been compared and discussed in connection with the electronic structure of the elements and with the alloy theory by Engel concerning the phase stability of solid solution between IB metals and typical normal metals.
  • 小川 洋一, 尾崎 太, 吉松 史朗, 千葉 光一, 梅田 博司, 佐伯 正夫
    1991 年 55 巻 5 号 p. 545-552
    発行日: 1991年
    公開日: 2008/04/04
    ジャーナル フリー
    The laser material purification (LMP) technology for rare metals in vapor phase was investigated. The selective photoexcitation and the photoionization of neodymium by laser were studied to develop a highly efficient and selective ionization process. Neodymium atom is effectively ionized throgh the new 3-steps ionization scheme by a single color laser beam of 577.612 nm in this process. Metallic neodymium was refined with this process and the concentration of praseodymium, which was a main impurity decreased by an order of magnitude. The LMP is to be an in-situ refining technology in a thin film fabrication process.
  • 水野 忠彦
    1991 年 55 巻 5 号 p. 553-557
    発行日: 1991年
    公開日: 2008/04/04
    ジャーナル フリー
    The diffusion behaviour of hydrogen and deuterium in Zr during cathodic discharge was studied by direct measurement of their concentrations. These were estimated by a volumetric measurement of the chemical dissolution of the metal hydride layer and a d-d fusion method of deuteron bombardment to the metal layer including deuterium. The diffusion behaviour was analysed with a simple push model that the diffusing hydrogen or deuterium atom interact directly with another hydrogen or deuterium atom composed hydride or deuteride. The activation energy of diffusion for hydrogen and deuterium in their hydride layer showed the same value of 49.0 kJ /mol and they were almost the same as in other papers. But the diffusion coefficients of hydrogen (DDH) and deuterium (DHD) showed a big difference; the ratio of DDHDHD=14.4 is extremely large compared with another value of nearly 3 obtained using a conventional diffusion model. The reason for the big difference is considered as follows. The diffusion process can be divided into several stages of the fundamental process. They are the discharge of the hydrogen ion from the solution to metal surface adsorption, the dissolution to metal from the surface, the diffusion through the hydride layer and the combination with the metal atom. The ratio of DDHDHD for this model has a value of less than 4. But in the case of the push model in which the hydrogen atoms interacts with each other, the ratio becomes 11.3.
  • 打越 哲郎, 目 義雄
    1991 年 55 巻 5 号 p. 558-563
    発行日: 1991年
    公開日: 2008/04/04
    ジャーナル フリー
    Temperature-programmed desorption (TPD) experiments of iron ultrafine powders (UFPs) prepared by the “hydrogen plasma-metal” reaction method, which had been subjected to a slow oxidation and exposure to air, was carried out, and compared with those of iron UFPs prepared by the vaporization method. These thermal desorption spectra were similar to each other. This means that the gas evolution spectra do not depend on the preparation methods of the powders, but depend on the surface conditions of the iron.
    Surface compounds of iron UFPs after exposure to air and their role in the passivity in air were also investigated from the thermal desorption characteristics of the iron UFPs prepared by the vaporization method. After reduction, re-slow oxidation and followed by exposure to water vapour or mixture of water vapour and oxygen, thermal desorption experiments were carried out for the iron UFPs prepared by a vaporization method. The surface layers of iron UFPs consisted of Fe3O4, γ-Fe2O3 and iron oxyhydroxide. The formation of Fe3O4 or γ-Fe2O3 on the clean iron surface and followed by the formation of iron oxyhydroxide on these oxides were effective for the stabilization of the powder against atmospheric oxidation (corrosion). We demonstrate that iron UFPs, which have a large specific surface area, are excellent as a sample for the investigation of the gas adsorption and desorption characteristics of the iron surface.
  • 加藤 雅敏, 榊 孝
    1991 年 55 巻 5 号 p. 564-570
    発行日: 1991年
    公開日: 2008/04/04
    ジャーナル フリー
    Cr is widely used as an essential alloying element for various stainless steels and alloys. Metalic Cr has poor workability in itself and therefore scarcely be used. Recently the high purity Cr sheets have been developed by the improved processing techniques such as electolytic winning, powder refining and rolling, so that various types of sheets and pipes can be fabricated. However, the corrosion behaviour of pure Cr has not yet been completely investigated.
    The corrosion behaviour of 99.83%Cr compared with Fe-Cr alloys and Ti was investigated by measuring the polarization curves and corrosion rates in various formic acid solutions. The repassivation rate was measured using the potential pulse method in order to investigate the stability of the surface films.
    Cr showed a large value of active dissolution current in formic acid solutions, but its passive current density was very small. And the repassivation rate of Cr was higher than the other materials. Cr had much better corrosion resistance in formic acid solutions than Ti and other Fe-Cr alloys. The corrosion behaviour of Cr depended on the formic acid concentration. On the other hand, the formic acid concentration exerted a greater influence on the corrosion behaviour of Fe-30Cr alloy than Cr. The Fe-30Cr alloy did not show any repassivation ability in various formic acid solutions except the low concentration and low temperature conditions.
  • 吉川 昇, 相川 晴彦, 菊池 淳
    1991 年 55 巻 5 号 p. 571-580
    発行日: 1991年
    公開日: 2008/04/04
    ジャーナル フリー
    Reactant gas mixtures (TiCl4, H2, N2) were introduced to the tublar reactor and TiN films were deposited on the inner wall of the reactor at different conditions (temperature, total gas flow rete, TiCl4 concentration).
    X-ray diffractometry and SEM observations were carried out to characterize the microstructures of the films. It was found that morphologies consisting of tiny needle-like and planar crystals appeared in the upstream regions, while the morphologies consisting of coarsened polyhedral grains with (110) orientation appeared in the downstream region.
    The variation of the deposition temperature mainly influenced the grain size of the films. The total gas flow rate was responsible for the positions at which these morphologies appeared, and the higher TiCl4 concentration gave rise to finner structures and less dominant (110) orientation.
    The relationships between the film morphologies and their crystal orientation were studied by TEM observations.
  • 西川 幸男, 田中 邦生, 吉田 善一
    1991 年 55 巻 5 号 p. 581-587
    発行日: 1991年
    公開日: 2008/04/04
    ジャーナル フリー
    The change in morphologies of laser ablated particles by using excimer laser are shown. The KrF excimer laser beam is irradiated on Ni film targets with thicknesses of 0.05-0.33 μm. Then particles are brought off from a target to a substrate. Particles on the substrate are examined by an optical microscope and S. E. M.. The main results obtained are as follows.
    (1) The particle morphology depends on the combination of target thickness and laser fluence. It changes from flake, globe, plate to film particles as the laser fluence increases.
    (2) The particle morphology depends greatly on the target thickness when the particles are thinner than 0.1 μm. On the other hand, the dependence on the target thickness is small when the particles are thicker than 0.1 μm.
    (3) Particles whose diameters are smaller than 0.5 μm decrease with increasing distance between the target and the substrate.
    (4) Globe, plate and film particles have a f.c.c. structure with the 0.33 μm thickness target.
  • 吉沢 克仁, 山内 清隆
    1991 年 55 巻 5 号 p. 588-595
    発行日: 1991年
    公開日: 2008/04/04
    ジャーナル フリー
    The typical nanocrystalline Fe73.5Cu1Nb3Si13.5B9 alloy called “Finemet” has been studied in regard to the dependence of the magnetic properties on the annealing condition and the relationship between the magnetic properties and the formed phase microstructure.
    The annealing condition under which the bcc phase is formed in the alloy leads to excellent soft megnetic properties. However, the formation of a compound phase deteriorates soft magnetic properties. The residual amorphous phase appears to decrease with rising annealing temperature. The small magnetostriction and the ultrafine grain structure lead to excellent soft magnetic properties. The grain boundary phase which has lower magnetic induction than the gain phase influences soft magnetic properties.
  • 塚本 武彦, 中村 泰教, 野口 精一郎
    1991 年 55 巻 5 号 p. 596-600
    発行日: 1991年
    公開日: 2008/04/04
    ジャーナル フリー
    Thin films of the Bi system have been prepared on MgO substrates by a repeat-sputtering method from a single sintered target. Sputtering was carried out in a mixed gas of argon and oxygen with a oxygen concentration of 20% without heating the substrate. The deposition rate was about 2.3 nm/min and the film thickness ranged from 400 to 600 nm. The films were crystallized though annealing in a muffule furnace.
    Our procedure for preparation of the superconducting films by low-temperature annealing are as follows: About 150 nm-thick film was deposited on MgO substrate. After annealing, we superimposed an amorphous film with the same thickness on the annealed film, and then the film was annealed similarly. The cycle of deposition and annealing was repeated until the desired thickness is obtained. This repeat-sputtering method is useful for preparation of the higher-Tc films. Moreover, the film surface is relatively smooth. The Tczero depends on the value of resistivity at 300 K, ρ (300 K), and the Tczero increases with decreasing ρ (300 K). And, metallic behaviour is observed above the superconducting on the set temperature.
    When a BiPbSrCaCuO target was used, we covered the amorphous film with MgO substrate and placed it in the furnace together with Pb3O4 to suppress the loss of Pb during the annealing. It is confirmed that the Pb promotes crystallization of the 110 K phase. The target with composition Bi1.8PbxSr1.0Ca1.2Cu1.8Oy yields the maximum volume fraction of the 110 K phase at x=0.2. The Ag addition into the BiPbSrCaCuo target raises Tczero. By the repeat-sputtering method, we obtained the thin films with Tczero≥105 K in a shorter annealing time than by the conventional method.
  • 比内 正勝, 沢谷 昭八, 増本 量
    1991 年 55 巻 5 号 p. 601-604
    発行日: 1991年
    公開日: 2008/04/04
    ジャーナル フリー
    The logarithmic decrement δ and the rigidity modulus G were investigated for heat-treated and cold-worked Al-Ge alloys containing 2 to 20 mass%Ge. The δ and G values were measured by an inverted torsion pendulum method.
    The δ values upon furnace cooling were somewhat higher than those upon water quenching, which were as low as 0.007. By cold working after heat treatment, the δ values of all alloys were increased considerably. With increasing Ge concentration, the δ upon cold working increased abruptly to 5 mass%Ge and then increased gradually. Moreover, in alloys cold worked after furnace cooling, the δ became higher than those cold-worked after water quenching.
    With increasing Ge concentration, the G increased, and cold working after heat treatment caused G to decrease. The ΔG effect increased abruptly up to 5 mass%Ge and then increased gradually, and high δ values were obtained in the alloys with a large ΔG effect.
  • 高橋 裕, 須賀 唯知
    1991 年 55 巻 5 号 p. 605-606
    発行日: 1991年
    公開日: 2008/04/04
    ジャーナル フリー
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