日本金属学会誌
Online ISSN : 1880-6880
Print ISSN : 0021-4876
ISSN-L : 0021-4876
49 巻 , 5 号
選択された号の論文の15件中1~15を表示しています
  • 高橋 徹, 堀内 良
    1985 年 49 巻 5 号 p. 299-305
    発行日: 1985年
    公開日: 2008/04/04
    ジャーナル フリー
    The grain boundary sliding behavior was investigated in coincidence boundaries of Zn and Al bicrystal specimens, in order to demonstrate the applicability of the DSC dislocation model. Two coincidence boundaries, viz. a ⟨10\bar10⟩ symmetric tilt boundary with a {1\bar216} boundary plane in Zn and a ⟨1\bar10⟩ symmetric tilt boundary with a {113} boundary plane in Al, were examined. Coupling of sliding and migration was observed on both boundaries. The ratio of the amount of grain boundary migration to that of grain boundary sliding was measured to be about 8 for the Zn {1\bar216} boundary and about 3 for the Al {113} boundary. The ratios and the migration directions were in accordance with the theoretical prediction based on the DSC dislocation model.
  • 渡辺 慈朗, 菅原 茂夫, 船渡 昭弘
    1985 年 49 巻 5 号 p. 306-312
    発行日: 1985年
    公開日: 2008/04/04
    ジャーナル フリー
    Dynamic behaviour of the solid-liquid interface and crystal defect during the melt growth of a Bi thin foil (99.9% in purity) has been observed using a transmission electron microscope and a TV imaging system. The (11\bar1) foil was melted and regrown with the same orientation as the original foil by cooling the melt at the rates from 8.3×10−3 to 2.7×10−1 K/s. The growth interface was concave toward the melt when the cooling rate was low and it became nearly flat when the cooling rate was high. Moreover, three types of the interface motion were observed during crystal growth; (a) a vibrational motion of back-and-forth at the slow cooling rate, (b) a vibrational motion of advancement and stoppage at the intermediate cooling rate and (c) a steady advancement at the high cooling rate. The vibrational interface motion was found to be due to a small fluctuation of temperatures during crystal growth. However, no facet growth was seen at any cooling rate against expectation.
    In the grown crystals various kinds of defects were observed: (1) short and long dislocations and dislocation loops, (2) lineage defects probably consisting of a dislocation array, (3) circular voids and (4) triangular defects not identified. The formation and behaviour of these defects during the melt growth and subsequent cooling processes were explained and their density and size were estimated. Among the defects generated in the crystals following three are most dominant; short dislocations of 0.1 μm in average length, dislocation loops of 0.05 μm in average diameter and circular voids of 0.03 μm in average diameter.
  • 瀧本 昭夫, 西原 良治, 庄田 俊二
    1985 年 49 巻 5 号 p. 313-319
    発行日: 1985年
    公開日: 2008/04/04
    ジャーナル フリー
    A logarithmic mixture rule expresses the relationship between the electrical resistivity and the volume fraction of the lenticular martensite produced in quench and sub-zero treatments and also in tensile deformation on an Fe-27.59Ni-0.28C(mass%) steel. The deviation coefficient varying between the negative and the positive unity in the expression is mainly discussed on the amount of plastic strain and the micro-deformation behaviour of the austenite matrix. The volume fraction of the deformation induced martensite is examined to be suitably represented by both the modified relation of the velocity of an autocatalytic chemical reaction (VACR) and the relation of the shear band intersection mechanism (SBIM), and here we use the modified relation of VACR from the fact that the transformation in this steel is more or less of the burst type and that this needs two coefficients to be determined compared with three in the other. The mathematical relationship between the plastic strain and the change in the electrical resistivity deduced from the previous two equations gives satisfactorily the experimental results in this study.
  • 圓城 敏男, 黒田 敏雄
    1985 年 49 巻 5 号 p. 320-326
    発行日: 1985年
    公開日: 2008/04/04
    ジャーナル フリー
    The behavior of hydrogen absorption and hydride precipitation has been studied on a Ti-6Al-4V alloy cathodically charged at various current densities using X-ray diffraction analysis, internal friction measurement and transmission electron microscopy.
    The 200 spacing and considerable X-ray line broadening of β phase increased with increasing cathodic charging time. The α phase, however, was not significantly affected by the cathodic charging.
    A relaxation peak relating to the hydrogen atoms in the β phase was observed in the internal friction versus temperature curve. The increase in the peak height corresponded to the increase in the 200 spacing of β phase in the X-ray line profile.
    Hydrogen atoms in the β phase were detected by both the internal friction measurement and X-ray diffraction analysis. It was observed that the hydrides mainly precipitated at the α/β interface for cathodic charging of the low current density, but precipitated in both the α phase and the β phase for the high current density.
    The precipitation amount of hydrides estimated from the X-ray line profile and the peak height at 190-220 K in the internal friction versus temperature curve increased with increasing charging time for the high current density. Consequently, the peak was considered to be related to the hydrides. The hydrides were detected by internal friction, though it was difficult to detect the hydrides by using X-ray diffraction analysis for the low current density.
  • 羽木 秀樹, 林 安徳
    1985 年 49 巻 5 号 p. 327-331
    発行日: 1985年
    公開日: 2008/04/04
    ジャーナル フリー
    The diffusion of hydrogen and deuterium in commercially pure iron specimens variously deformed and annealed has been investigated between 283 K and 318 K by an electrochemical permeation method. The temperature dependence of the diffusion coefficients of hydrogen (DH) and deuterium (DD) is discussed on the basis of the trapping theory. The ratio DH/DD is temperature dependent, but the dependence of the ratio upon dislocation density is not found. This indicates that the trap density and binding energy are, within experimental error, the same for hydrogen and deuterium, and the activation energy of diffusion in normal lattice sites is mass dependent. The binding energies with trapping sites (dislocations) for both hydrogen and deuterium in iron are about 27 kJ/mol.
  • 中西 典彦, 村上 勇一郎
    1985 年 49 巻 5 号 p. 332-336
    発行日: 1985年
    公開日: 2008/04/04
    ジャーナル フリー
    The effect of Ag addition on the bainitic transformation and the stability of the CuZn β phase alloy were studied by electron microscopy. In a Cu59Zn40Ag1 alloy, a large number of small particles, probably nuclei, of bainite with diameter of 20-100 nm were observed in the early stage of aging at 513 K. During further aging, the growth of bainite plates was observed. These are similar to the bainitic behaviour in the binary CuZn alloy. In Cu55Zn42Ag3 and Cu50Zn45Ag5 alloys, the β phase decomposed into Cu rich and Cu poor (i.e. Ag and Zn rich) regions, and the bainite plates were grown only in the Cu rich region. By the addition of Ag more than 3 at% the β phase showed so strong tendency to the phase separation as to suppress the growth of bainite plates.
  • 有働 公一, 沖 憲典, 江口 鉄男
    1985 年 49 巻 5 号 p. 337-343
    発行日: 1985年
    公開日: 2008/04/04
    ジャーナル フリー
    The process of atomic ordering and disordering of an Fe-22.2 at%Ga alloy during the isothermal annealing was investigated by means of X-ray diffraction and electron microscopy. The DO3 type ordering was so rapid in this system that the alloy solution treated at 1023 K and then quenched consisted of fine DO3 domains formed during the quenching. At 873 and 773 K, the DO3 phase was in the metastable state, though the equilibrium state of the alloy was in the mixture of two phases, disordered A2 and ordered L12. During the annealing of quenched alloy at 873 K, the disordering of metastable DO3 phase took place by the decomposition. The DO3 phase was disordered homogeneously at 773 K, because Ga content in the DO3 phase lowered owing to the precipitation of highly ordered stable L12 phase.
  • 斉藤 勝男, 日景 武夫
    1985 年 49 巻 5 号 p. 344-351
    発行日: 1985年
    公開日: 2008/04/04
    ジャーナル フリー
    Activation volume in the tensile deformation of Cu-Ni (Ni: 0.49-9.56 mol%) alloy single crystals with the same orientation has been investigated by means of the stress relaxation test in the temperature range from 77 to 473 K. The shear strain, the resolved shear stress and the solute concentration dependence of the activation volume were obtained.
    The activation volume in the stage I is almost independent of the shear strain, but in the beginning of the stage II it decreases abruptly with increasing shear strain. Dependence of the activation volume, V, on the resolved shear stress, τ, differs between the low and high stress regions. When we write the shear stress dependence of the activation volume as V=Kτn, where K is constant, the obtained value of n is close to either 1⁄3, 1⁄2, 2⁄3 or 1. The cases of n=1⁄2 and 1 are discussed with the stress dependence of dislocation density.
    The activation volume at the initiation of the deformation depends on the concentration of nickel, CNi, by the type of V=KCNik, where K′ is constant. The value of k(<1) increases from 1⁄2, which is the value extrapolated to 0 K, with increasing temperature. The concentration dependence of the activation volume is discussed based on the theory of solid solution hardening. The case of k=1⁄2 at 0 K is well described by the Fleischer-Friedel model.
  • 井口 義章, 山南 弘文, 平尾 次郎
    1985 年 49 巻 5 号 p. 351-356
    発行日: 1985年
    公開日: 2008/04/04
    ジャーナル フリー
    This study was performed to ascertain the authors’ consideration that the magnitude of the flux of cation vacancy diffusing into the reaction interface may determine the morphology of reduced iron. Wustite plates of about 1.5 mm thickness and wustite foils produced by the unidirectional oxidation of iron foils of 200, 70 and 25 μm thicknesses in situ were used as specimens. In the reduction of wustite plates, pores were formed in wustite before iron formation, and thereafter iron was formed on the pores. A region of the highest reduction degree was located not on the exterior surface in contact with the reducing gas but in a place distant from the surface. In the reduction of wustite foils, the reaction interface receiving the in-flux of vacancies advances much more rapidly than that not receiving it. The effect of cation vacancies diffusing into the interface on the distance between iron nuclei and the elongation rate of pores in wustite was discussed.
  • 下尾 聰夫, 安藤 繁, 木村 弘
    1985 年 49 巻 5 号 p. 357-363
    発行日: 1985年
    公開日: 2008/04/04
    ジャーナル フリー
    In relation to the alkali recycle in a blast-furnace, the rate of vaporization of potassium from slags was investigated. At temperatures between 1723 and 1923 K and under argon atmosphere, the mass loss from the slag melted in a graphite crucible as a reductant was continuously measured by means of a thermo-balance.
    At lower temperatures, the mass loss was due almost to the vaporization of K, but at higher temperatures, particularly in the slags with high concentrations of SiO2, there was concurrent evolution of K and SiO from the slag. The rate of vaporization was represented by the first-order-type rate equation. The rate constant were in the range from 9.5×10−8 to 4.6×10−7 m/s at 1773 K. It was found that the rate constant increased with increasing basicity of blast-furnace-type slags. The apparent activation energy varied from 173 to 314 kJ/mol with slag composition. It was observed that the rate of K vaporization was strongly dependent on the wetting of slag on the graphite crucible wall. The vaporization of K from the slag was controlled by the chemical processes at the slag-graphite interface.
  • 松井 眞悟, 恵羅 彰男
    1985 年 49 巻 5 号 p. 364-368
    発行日: 1985年
    公開日: 2008/04/04
    ジャーナル フリー
    A study was made on the rate and the equilibrium of aluminum extraction from hydrochloric acid solution with di-2-ethylhexyl phosphoric acid (DEHPA) in paraffine diluent.
    From the equilibrium study, it was concluded that AlR3·HR was the extracted species in the organic phase.
    In the kinetic study, the influence of pH of the aqueous phase and the extractant concentration in the organic phase on the extraction rate was investigated. The experimental data were well explained by assuming that the extraction reaction proceeded along two parallel paths described below.
    The first path was shown by the following reactions with Al3+ ion;
    (This article is not displayable. Please see full text pdf.)
    \ oindentEither equation (\ efe3) or (\ efe4) was assumed to be the rate determing step.
    The second path was shown by the following reactions with AlOH2+ ion;
    (This article is not displayable. Please see full text pdf.)
    \ oindentThe equation (\ efe5) was posturated to be the rate determing step.
    The kinetic parameters calculated in this study were compared with those obtained in previous studies on 2-ethylhexyl phosphonic acid mono-2-ethylhexyl ester (DEHEHP).
    In the first reaction path, where the reaction rate was assumed to be propotional to 1.5 or 2 powers of the extractant concentration in the organic phase, the value of the kinetic constant kf1 calculated in this study was about 50 times as large as those obtained in the systems with DEHEHP in hydrochloric, nitric and sulfuric acid solutions.
    In the second path from AlOH2+ ion, where the reaction rate was assmed to be independent of the extractant or its concentration in the organic phase, the calculated value for the kinetic constant kf2 agreed very well with those obtained in the systems with DEHEHP.
  • 佐藤 知敏
    1985 年 49 巻 5 号 p. 369-375
    発行日: 1985年
    公開日: 2008/04/04
    ジャーナル フリー
    Feathery crystals formed in Al-7.0 mass%Si, Al-4.0 and 6.0 mass%Cu alloys which were poured into molds at 1163 K and water-cooled on and off during unidirectional solidification were observed microscopically to examine their morphology and etch pits for estimating crystal orientation. Results obtained were as follows:
    (1) The feathery dendrites in the 7.0 mass%Si alloy have an appearance of a V-shape in the early stage of growth, but later gradually changed into a Y-shape. Primary stalks of the feathery dendrites become very long in the late stage of growth.
    (2) The primary stalks of the feathery dendrites in the 4.0 and 6.0 mass%Cu alloys seem to be short in both the early and the late stages of growth, but they are connected slightly with other primary stalks or sidebranches.
    (3) The primary stalks of the feathery dendrites grow in the direction of ⟨110⟩, but the secondary branches grow in ⟨100⟩ or ⟨112⟩.
    (4) The secondary branches of the feathery dendrites in the early stage are sometimes observed to be growing long upward as columnar dendrites.
    (5) In the 4.0 and 6.0 mass%Cu alloys, the primary stalks in the feathery dendrites sometimes grew at angles between 5° and 10° from the surface trace of the growth twin plane, and in other cases the surface trace was parallel to the growth direction of the primary stalk, but deviated from the central line of the stalk.
    (6) In the feathery dendrites, ternary branches are easily generated from secondary branches, but distinguishing the primary stalks from the ternary ones is extremely difficult. This multiplication mechanism of the feathery dendrites may be a controlling mechanism of the primary arm spacing of the columnar dendrites.
  • 山田 銑一, 砥綿 真一
    1985 年 49 巻 5 号 p. 376-381
    発行日: 1985年
    公開日: 2008/04/04
    ジャーナル フリー
    The linear thermal expansion of unidirectional and angle plied silicon-carbide fiber-reinforced aluminum alloys was measured as functions of fiber and plying angles. These composites were prepared by a squeeze casting method, and pure Al and an Al-4.5%Cu alloy were used as matrix metals.
    The results are as follows:
    (1) Transition points TA and TB were observed in the thermal expansion curves for all the specimens measured. TA corresponds to the transition from elastic to plastic deformation of the matrix, and TB corresponds to the transition from plastic deformation to plastic flow of the matrix.
    (2) The linear thermal expansion coefficients of the composites measured in the longitudinal and transverse directions agreed very well with the values calculated from Schapery’s theoretical equations. In the calculation, the tensile moduli and Poisson’s ratios of the matrix alloys were used as the elastic values below TA temperature, while Em=0 GPa and νm=0.5 were used as plastic values for temperatures above TB.
    (3) From the above values, the linear thermal expansion coefficients were calculated for arbitrary directions by modifying the Uemura’s theoretical equation. In the ranges of (T0TA) and (TBT573), a good correlation was obtained between the calculated and observed coefficients.
  • 柴田 美智男, 天野 宗幸, 佐々木 靖男, 菅 広雄
    1985 年 49 巻 5 号 p. 382-385
    発行日: 1985年
    公開日: 2008/04/04
    ジャーナル フリー
    Chemical analyses and measurements of hydrogen storage properties have been carried out on samples prepared by melting a standard sample of FeTi1.13 in graphite, Al2O3, MgO and ZrO2 crucibles; this standard sample was prepared by use of a water-cooled crucible of copper. The carbon contamination of the sample melted in the graphite crucible was less than 0.1 mass%, and the hydrogen storage property of the sample was nearly the same as that of the standard sample. On the other hand, the impurity contamination of the samples melted in the Al2O3, MgO and ZrO2 crucibles was remarkable, and the amounts of hydrogen stored in these samples were much smaller than that of the standard sample. The hydrogen storage properties of the samples melted in the MgO and ZrO2 crucibles which were used twice were not inferior to that of the standard sample, but the erosion of the crucibles successivley occurred in their repeated uses. It is concluded that a graphite crucible is suitable for the mass production of FeTi.
  • 高橋 裕, 森 実, 石田 洋一
    1985 年 49 巻 5 号 p. 386-387
    発行日: 1985年
    公開日: 2008/04/04
    ジャーナル フリー
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