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45 巻, 9 号
選択された号の論文の17件中1～17を表示しています
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小山 泰正, 入戸野 修1981 年 45 巻 9 号 p. 869-877
発行日: 1981年
公開日: 2008/04/04
ジャーナル フリーThe martensitic transformations in In-(18∼30 at%)Tl and In-(4.0∼5.5 at%)Cd alloys (fcc→fct:c⁄a>1), In-(28∼35 at%)Pb alloys (fcc→fct:c⁄a<1), In-(12∼16 at%)Pb alloys (fct:c⁄a<1→fco→fct:c⁄a>1) and In-(13∼15 at%)Sn alloys (fct:c⁄a<1→fct:c⁄a>1) have been studied by means of X-ray and electron diffraction. Intensive thermal diffuse scattering is observed on the {110} reciprocal lattice planes in all the indium-rich solid solutions. The mechanism of the phase transformations is discussed on the basis of the observed diffuse scattering due to the lattice vibration. An octahedral cell model composed of ⟨110⟩ atomic chains is useful to explain the atomic movements of the phase transformations. The displacement mode of atoms, which is expressed in terms of linear combination of the strain tensor components, corresponds to the basis belonging to the two-dimensional represnetation Eg of the point group Oh. Actual atomic movements of the phase transformations in indium-rich solid solutions can be given as a result of coupling of two predominant phonons, on the assumption that one phonon mode corresponds to one cooperative atomic movement. The shape memory effect, which is associated with a reverse transformation from a low temperature phase to a high temperature one, is well explained in terms of crystallographical reversibility between the two phases. It is shown that the crystallographical reversibility is related with the change in crystal symmetry during the phase transformation.抄録全体を表示PDF形式でダウンロード (975K) -
日向寺 雅彦, 堀 誠, 入戸野 修, 長倉 繁麿1981 年 45 巻 9 号 p. 878-887
発行日: 1981年
公開日: 2008/04/04
ジャーナル フリーCadmium single crystals (99.99% pure), prepared both by the Bridgman method and a solidification technique especially designed to obtain flat crystals, were studied at normal and elevated temperatures by means of X-ray diffraction topography. The former crystals contained a large number of subgrain boundaries, while the latter crystals generally tended to have their wide faces very close to the (0001) planes and contained a small number of subgrain boundaries as well as dislocations. A thermal-cyclic annealing, applied in a range of temperature between 493 and 553 K, and a subsequent isothermal annealing at 473 K prepared a large single crystal with a low dislocation density of less than 103 cm/cm3. When the cadmium crystals were grown and then cooled to room temperature, no dislocation loops were observed, but after 5 to 9 d of leaving in the ambient atmosphere several dislocation loops and dislocation dipoles appeared. The nucleation and growth of such dislocations were explained by considering that the cadmium crystals are oxidized on their surfaces and the formation of oxide layers supplies a lot of vacancies to the inner parts of the crystals. Dislocation loops having c and c+a types of Burgers vector increased their diameter during about 30 d (2.6 Ms) and then shrinked, and the dislocation loops with Burgers vector c extended 3 times faster than those with Burgers vector c+a. The behavior of such dislocation loops was discussed in terms of the vacancy saturation, the line tension of dislocation and the surface state of the oxide layer.抄録全体を表示PDF形式でダウンロード (1466K) -
草開 清志, 白石 裕1981 年 45 巻 9 号 p. 888-895
発行日: 1981年
公開日: 2008/04/04
ジャーナル フリーIn order to elucidate the behavior of Al2O3 in the silicate melt, infrared emission spectra of the Na2O-Al2O3-SiO2 system were measured in the molten state and were compared with the spectra measured in the glassy state.
Results obtained from the in situ measurements are summarized as follows:
(1) Since the spectra measured in the molten states are very similar to those in the glassy states, it is concluded that there is no essential difference between the silicate anions in the molten and the glassy states.
(2) When Al2O3 is added to sodium silicates, a band at about 75000 m−1 due to the Al-O bond appears in much the same position as that of the SiO4 total symmetric stretching mode. The intensity of this band is proportional to the Al2O3 content. It is obvious by comparison with the available crystalline state that this band can be assigned to the stretching mode of the AlO45− structure. Therefore, it is recognized that most of the Al3+ ions take the form of the tetrahedrally coordinated oxygens in the molten and glassy silicates.
(3) The ratio of the area of the absorption band due to the Si-O(BO) stretching mode to the sum of those of the Si-O(BO) and the Si-O− (NBO) stretching medes decreases with increasing Na2O and/or Al2O3 content in the silicate. This means that Al2O3 breaks the silica network. To arrive at the compatibility with the other properties, however, it must be considered that Al2O3 does not behave as a simple network modifier as Na2O does, but acts as a network former, breaking the silica network in the silicate melt within the measured composition range.抄録全体を表示PDF形式でダウンロード (623K) -
草開 清志1981 年 45 巻 9 号 p. 896-901
発行日: 1981年
公開日: 2008/04/04
ジャーナル フリーIn order to obtain the vibrational spectra of molten alkaline and silver surfates, infrared emission spectra were measured at a temperature 50 K higher than their melting points. Transmission spectra were derived from combination of the two emission spectra which were obtained from thin and thick layers of samples.
Results obtained from the in situ measurements are summarized as follows:
(1) The vibrational bands ν3, ν4, ν1 and ν2 for SO42− are observed in any sulfates. Accordingly, the SO42− anion structure exists in the molten state.
(2) Although general patterns and relative intensities of their spectra are almost similar, the vibrational frequencies ν3, ν4, ν1 and ν2 clearly decrease in the order Li+>Na+>K+>Rb+>Ag+.
(3) It is concluded that the SO42− anion of sulfate melts has a structure with a little lower symmetry than the Td, because the forbidden bands ν1 and ν2 are slightly observed.
(4) In the case of LiKSO4 melt, the band which does not appear in pure Li2SO4 and K2SO4 melts is broadly observed at 40000 m−1.抄録全体を表示PDF形式でダウンロード (483K) -
寺山 清志, 池田 正夫1981 年 45 巻 9 号 p. 901-908
発行日: 1981年
公開日: 2008/04/04
ジャーナル フリーThe reduction kinetics of Mn oxides with carbon was investigated in order to study the characteristics of pre-reduction of Mn ores and to clarify the catalytic action for the oxidation of carbon.
(1) For the reduction of MnO2, thermal decomposition of MnO2 occurs preferentially, and the activation energy of 175 kJ/mol, which corresponds to that for thermal decomposition of MnO2, is obtained.
(2) At temperatures below 913 K for the reduction of Mn2O3, the activation energy is 226 kJ/mol and thermal decomposition of Mn2O3 is thought to be a rate determining step. Above 913 K, the reduction process of Mn2O3 seems to be controlled by the diffusion of reactant and product gases through the product layer.
(3) For the reduction of Mn3O4, the activation energy of 289 kJ/mol nearly equal to that for the Boudouard’s reaction is obtained and this Boudouard’s reaction seems to be catalyzed by Mn3O4.
(4) The nonstoichiometric MnO1.61, MnO1.42 and MnO1.11 seem to be formed in the reduction process of MnO2, Mn2O3, Mn3O4 at 843, 1003, 1153 K, respectively.抄録全体を表示PDF形式でダウンロード (605K) -
西村 六郎, 佐藤 教男1981 年 45 巻 9 号 p. 908-914
発行日: 1981年
公開日: 2008/04/04
ジャーナル フリーThe composition, structure and thickness of passive films on iron in acidic phosphate solutions of pH 1.85 to pH 5.90 have been investigated as a function of electrode potential by using ellipsometric and electrochemical techniques. From ellipsometric measurements of δP-δA curves during galvanostatic-cathodic film reduction, it is found that the passive film consists of a barrier layer and a deposit layer, and that the latter layer disappears in the pH region below pH 2. Below pH 5.5, the former layer can be divided into two layers; an outer layer and an inner layer. The outer barrier layer thickness decreases with increasing pH and becomes zero at pH 5.5. At a constant overpotential of anodic oxide formation, the total thickness of the barrier layer tends to increase with increasing pH. Chemical analyses of iron ion dissolved from the film during the cathodic reduction have shown that the deposit layer exihibits no change in its composition with pH and that the composition of the inner barrier layer differs from that of the outer barrier layer, the former showing the mean oxidation state of ZFe\fallingdotseq2.67 and the latter the mean oxidation state of ZFe\fallingdotseq3.00, irrespective of the electrode potential and pH. Enrichment of iron ions is found to occur at the inner barrier-outer barrier layer interface as well as at the interface between the outer barrier layer and the deposit layer. The electric field that occurs in the barrier layer at the steady state is estimated to be 1×109 V·m−1 in the inner barrier layer and 3×108 V·m−1 in the outer barrier layer of the passive film in phosphate solution at pH 1.85.抄録全体を表示PDF形式でダウンロード (578K) -
大楠 弘, 益田 穣司, 脇田 満信, 杉之原 幸夫1981 年 45 巻 9 号 p. 915-922
発行日: 1981年
公開日: 2008/04/04
ジャーナル フリーThe improved trimethylsilylation method reported previously is used in order to determine silicate anions present in various crystalline silicates and to measure variation in the distribution of silicate anions in silicates during crystallization of glassy samples in CaO-50 mol%SiO2, CaO-43.3 mol%SiO2 and PbO-33.3 mol%SiO2.
Results of these experiments are summarized as follows:
(1) The orthsilicate crystal such as 2SrO·SiO2, 2CaO·SiO2 and 2ZnO·SiO2, and the pyrosilicate crystal such as 3CaO·2SiO2 are determined to be mainly composed of SiO44− and Si2O76− respectively, while the Li2O·SiO2 Crystal is considered to comprise infinite chains, because the trimethylsilylated derivative is not detected gas-chromatographically.
(2) On crystallization of glassy samples in CaO-50 mol%SiO2 and CaO-43.3 mol%SiO2, types of silicate anion determined by this method are in good agreement with those analyzed on the base of IR and X-ray powder data.
(3) On crystallization of glassy PbO-33.3 mol%SiO2, different temperatures of heat treatment for crystallization result in the presence of different types of silicate anions. This observation suggests the presence of various compounds of 2PbO·SiO2 as shown previously by Götz.
On the basis of the above results, it is concluded that this method is useful for the analysis of silicate anions in synthetic silicate crystals or glasses.抄録全体を表示PDF形式でダウンロード (644K) -
吉田 利三郎, 海保 恵亮, 井出 勇作, 山口 伝治郎1981 年 45 巻 9 号 p. 922-927
発行日: 1981年
公開日: 2008/04/04
ジャーナル フリーIron oxides, Fe3O4 and Fe2O3 were used to decrease the free carbon in the thermal decomposition products of prussian blue. Further more, the influence of inpurities contained in prussian blue, Na2SO4 and FeSO4·7H2O was also studied.
The products were studied by means of X-ray diffraction, chemical analysis and measurements of magnetic properties. Experimental results obtained and discussion of them are as follows.
(1) The prussian blue containing iron oxides decomposed to Fe3C, α-Fe and FeO depending on the amount of iron oxide added.
From the results of the magnetic measurements pure Fe3C was formed by decomposition of the starting material containing about 5 to 6% of oxygen. The Curie point of the Fe3C was 483 K.
(2) A mixture of prussian blue and Na2SO4 or FeSO·7H2O decomposed to Fe20C9, Fe7C3 and α-Fe, and formation of these products depended on the amount of sulfur in the starting material.
(3) In order to produce Fe3C, purer prussian blue which does not contain Na2SO4 and FeSO4. 7H2O as inpurities is needed as the starting material for prevention of the by-product, Fe2C.抄録全体を表示PDF形式でダウンロード (423K) -
坂本 芳一, 中道 雄二1981 年 45 巻 9 号 p. 927-934
発行日: 1981年
公開日: 2008/04/04
ジャーナル フリーThe hydrogen permeation through a two-phase metal layer of electrodeposited Pd/Ni and electrodeposited Cu/Ni foil composites has been investigated by the electrochemical permeation current method.
The observed build-up transient of hydrogen permeation through both the composites coincides with that predicted theoretically, not depending upon the thickness of the electrodeposits, and the diffusion of hydrogen in the composites during permeation is a rate determining step.
The diffusion coefficients of hydrogen in the electrodeposited Pd and Cu layers in the composites determined by the relation of (L1⁄\sqrtD1+L2⁄\sqrtD2)=Lcomp⁄\sqrtDcomp with the known diffusivity of hydrogen in the Ni foil substrate are in agreement with those measured by using one phase of them alone.
It is possible to determine an unknown diffusion coefficient of hydrogen from hydrogen permeation measurements through a two-phase metal layer by a simple relation of the theoretical solution of diffusion equation.抄録全体を表示PDF形式でダウンロード (579K) -
松木 賢司, 針山 典篤, 時沢 貢1981 年 45 巻 9 号 p. 935-941
発行日: 1981年
公開日: 2008/04/04
ジャーナル フリーSheet specimens of a fine grained Al-10.8 (mass)%Zn-0.85%Mg-0.29%Zr alloy were strained by about 25% at both superplastic and non-superplastic conditions. Contributions of grain boundary sliding and slip to the total specimen elongation (εgbs⁄εt and εslip⁄εt, respectively) were estimated metallographically.
Main results obtained are as follows:
(1) In the superplasic region, the contribution of grain boundary sliding was remarkably higher than that of slip, i.e. εgbs⁄εt\simeq0.6∼0.7 and εslip⁄εt\simeq0.15∼0.3. In the non-superplastic region, however, the grain boundary sliding contribution decreased and the slip contribution increased rapidly with increasing strain rate.
(2) The contribution of diffusional flow to the total specimen elongation (εdiff⁄εt) defined by 1−(εgbs⁄εt+εslip⁄εt) increased with decreasing strain rate.
(3) The stress component n and the activation energy Q for the three deformation processes were estimated from three strain rates \dotεgbs, \dotεslip and \dotεdiff, respectively. They were \dotεgbs∝σ2.0×exp(−80500⁄RT) and \dotεdiff∝σ1.0exp(−65300⁄RT) at a wide stress range, while \dotεslip∝σ2.2exp(−84500⁄RT) at lower stress showing superplasticity and \dotεslip∝σ4.9exp(−134100⁄RT) at higher stress. The slip at low stresses is suggested to be closely related to grain boundary sliding. The mechanism of the superplastic deformation of this alloy is discussed.抄録全体を表示PDF形式でダウンロード (569K) -
阿部 光延, 小甲 康二, 新井 信一, 速水 哲博1981 年 45 巻 9 号 p. 942-947
発行日: 1981年
公開日: 2008/04/04
ジャーナル フリーThe correlation between ductility in tensile test and nonuniform deformation has experimentally been investigated under various conditions (testing temperature: 193∼313 K, strain rate: 10−5∼10−1 s−1). Total elongation in specimens with large amounts of solute C is decreased by the dynamic strain aging, under the condition of which necking has a tendency to localize. Consequently the magnitude of local elongation after the maximum load point depends simply upon \barvd⁄(ξvs) only, low values of which are associated with occurrence of the dynamic strain aging, \barvd is average velocity of mobile dislocations, vs is diffusion velocity of C atoms and ξ is a constant depending upon the density and configuration of dislocations. In case of specimens having fine carbides in grains, the ductility deterioration under high strain rates at low temperatures is related to the localization of Lüder’s band.抄録全体を表示PDF形式でダウンロード (549K) -
李 絏, 川野 豊1981 年 45 巻 9 号 p. 948-956
発行日: 1981年
公開日: 2008/04/04
ジャーナル フリーIn the solid phase of the Fe-C alloy system, C atoms precipitate as graphite into defects such as voids in alloys. Therefore, the morphorogy and distribution of graphite may depend on those of the defects. In order to verify this assumption that had been previously presented by us and other investigators hyper-eutectoid Fe-C-Si alloys were heated to the austenite temperature range and held isothermally. Thereafter, the alloys were quenched in water or cooled to the graphitization temperature in a rate 0.17 K/s prior to graphitization.
Results obtained are as follows:
(1) In specimens containing Mg, spherical cavities less than 5 μm in size were observed and their number was decreased by the sweeping effect mainly due to migration of grain boundaries during the isothermal treatment. Micro-cracks were also observed in all quenched specimens.
(2) After the graphitization annealing, graphites in these specimens had a shape and distribution similar to the above-mentioned defects.
(3) It was suggested that the formation mechanism of graphites, which might be precipitated into spherical cavities and micro-cracks, would be substantially the same in these two cases, because characteristics of crystals resembled each the other in spite of much difference in their shapes in the observation of micro-structure of graphites.
(4) These experimental facts would directly prove the above-mentioned assumption on the precipitation mechanism of graphite.抄録全体を表示PDF形式でダウンロード (2924K) -
天野 宗幸, 佐々木 靖男, 吉岡 孝之1981 年 45 巻 9 号 p. 957-964
発行日: 1981年
公開日: 2008/04/04
ジャーナル フリーThe hydriding characteristics of composite materials composed of FeTi1+x(0≤x≤0.38) and oxide phases have been studied. The rate of hydrogen absorption in each composite material was measured at 298 K in a hydrogen atmosphere of 6 MPa after pulverizing the material to more than 100 mesh in air. The composite materials containing a titanium-rich alloy phase were hydrided after some incubation time, and this time became shorter with increasing amount of the oxide phase. The rate of hydriding for the composite materials composed of FeTi, βTi and oxide phases were especially rapid.
The experimental results can be well explained on the assumption that the titanium concentration in the surface oxide film on the titanium-rich alloy phase is high and such a film can absorb hydrogen even at room temperature. It is considered that hydrogen absorbed in the film can diffuse more rapidly through interfaces between the two phases and cores of edge dislocations into the composite materials.
It has been suggested that excellent hydrogen storage materials in the Fe-Ti-O sysem can be obtained by selecting a proper ratio of amounts of the FeTi, βTi and oxide phases.抄録全体を表示PDF形式でダウンロード (763K) -
小野寺 龍太, 清水 峯男, 古賀 守1981 年 45 巻 9 号 p. 965-971
発行日: 1981年
公開日: 2008/04/04
ジャーナル フリーThe Portevin-Le Chatelier effect has so far been investigated mainly in the field of the dislocation theory. The aim of the present study is to reveal behaviours of Lüders bands associated with the P-L effect. Local strains and strain rates were measured using strain gages stuck on the specimen surface. A quenched or annealed commercial 2017 Al alloy having a nominal composition of 4%Cu, 0.5%Mg and 0.5%Mn, was studied in the temperature range from 230 to 463 K at various strain rates.
The P-L effect corresponds to propagation of the Lüders band. The deformation of annealed specimens was confined within the Lüders band, but in quenched specimens the other regions continued to deform more and less. The Lüders strain increased with decrease of work hardening rate and it was independent of temperatures and strain rates. The velocity of the Lüders band was roughly proportional to the crosshead speed, and the band width was always between 1 and 15 mm. The strain rates within the Lüders band for the annealed specimen were almost always between 10−2 and 10−1 s−1, but those for the quenched were proportional to the crosshead speed. The critical strain, the strain to the onset of P-L effect, for quenched specimens was independent of strain rates at room temperature, and its magnitude was about 10%. At higher or lower temperatures it was greater than 15%. When the quenched specimens were aged for one day at room temperature after prestraining, the critical strain became less than 10%. At a given temperature the critical strain for annealed specimens took a minimum value, about 0.5%, at a certain strain rate, which was apt to increase with temperature.
In order to explain the above results and types of serrations, a phenomenological approach was attempted using macroscopic variables such a strain hardening rates and a negative strain rate sensitibity of flow stress.抄録全体を表示PDF形式でダウンロード (573K) -
大西 忠一, 東 健司, 井上 憲明, 中谷 義三1981 年 45 巻 9 号 p. 972-976
発行日: 1981年
公開日: 2008/04/04
ジャーナル フリーThe temperature and strain rate dependence of hydrogen embrittlement of an Al-8%Mg alloy have been investigated. Marked embrittlement is observed in a certain temperature range around room temperature, and is increased with decreasing strain rate. The recovery of the embrittlement occurs in two temperature regions. One is the region in which the recovery proceeds more rapidly with increasing temperature above 300 K and is independent of the strain rate. The other is the region in which the recovery proceeds more slowly with decreasing temperature below room temperature and strongly depends on the strain rate. The results are explained in terms of the interaction between diffusion of hydrogen and dislocations. The former is attributable to decrease in the saturated hydrogen content in the atmosphere around dislocations with increasing temperature, and the latter depends on the formation rate of the atmosphere around moving dislocations. Low temperature embrittlement is also observed. Its transition temperature is lowered with decreasing strain rate and is raised by hydrogen addition.抄録全体を表示PDF形式でダウンロード (379K) -
高田 潤, 清水 真人, 足立 正雄1981 年 45 巻 9 号 p. 977-983
発行日: 1981年
公開日: 2008/04/04
ジャーナル フリーTo clarify the mechanism of the high temperature deformation of dispersion hardened Cu base alloys, the high temperature deformation behavior of Cu-0.5 and 1.0 vol%SiO2 alloy single crystals, which were produced by means of internal oxidation, were investigated. Tensile tests were performed in the temperature range from 873 to 973 K at initial strain rates between 10−5 and 10−3 s−1. In the steady-state deformation, the stress exponent, the apparent activation energy for the high temperature deformation and the internal stress were measured for these alloys. Rotation of the specimen axis was examined by the X-ray Laue method.
While in the early stage of deformation the specimen axis rotates along the trace of single slip, it hardly rotates on reaching at the vicinity of the ⟨100⟩-⟨111⟩ boundary, and the steady-state deformation is realized. The steady-state strain rate is proportional to the seventh power of the applied stress. Values of the apparent activation energy for the high temperature deformation of Cu-0.5 and 1.0 vol%SiO2 alloys are 192 and 211 kJ·mol−1, respectively, and nearly equal to that for self-diffusion in copper. The internal stress is a main component of the applied stress in these alloys. These results indicate that the high temperature deformation of Cu-SiO2 alloys is controlled by a recovery process.
The experimental results in Cu-SiO2 alloys were discussed on the base of the creep theory of Ansell and Weertman for dispersion hardened alloys. The stress exponent in these alloys does not agree with the one expected from the theory.抄録全体を表示PDF形式でダウンロード (518K) -
1981 年 45 巻 9 号 p. 983
発行日: 1981年
公開日: 2008/04/04
ジャーナル フリー
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