巻号一覧
53 巻, 10 号
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渡辺 英雄, 青木 彰伸, 室賀 健夫, 吉田 直亮1989 年 53 巻 10 号 p. 981-990
発行日: 1989年
公開日: 2008/04/04
ジャーナル フリーMicrostructural evolution and radiation induced segregation under electron irradiation have been observed with a HVEM in pure Fe-16Cr-17Ni-0.1P-(0.1∼0.25)Ti alloys. It was shown that P atoms served as the nuclei for interstitial loops in the alloy containing both P and Ti as well as the alloy containing P only. In the alloys containing both P and Ti, vacancy loop formation was prominent even at higher temperatures compared with alloys containing P only. These phenomena resulted in a remarkable suppression of void swelling and radiation-induced Ni depletion in matrices. The swelling suppression seemed to be related with the P concentration in matrices. Because of the strong interaction between P and Ti, P segregation to the defect sinks (grain boundary, dislocation and free surface) was retarded maintaining the P effect to suppress swelling in the matrix. The formation of M2P-type phosphides which act as defect sinks at higher temperatures was enhanced by Ti addition. These results suggest that the co-addition of P and Ti is very effective for increasing swelling resistance.抄録全体を表示PDF形式でダウンロード (4401K) -
飴山 惠, 松岡 浩, 宮崎 昭洋, 時実 正治1989 年 53 巻 10 号 p. 991-997
発行日: 1989年
公開日: 2008/04/04
ジャーナル フリーThe change of microstructures in Fe-24%Cr-7%Ni (ferrite (α)+austenite (γ)) two-phase stainless steel during hot compressive deformation at the corresponding temperature of (α+γ) two phases was investigated. Two kinds of specinnens with different microstructures are prepared for the hot compressive deformation. One has a microduplex structure which consists of fine α subgrains and γ grains. The other has an α single phase structure which was deformed to the reduction of 80% in thickness by cold rolling and compression. In the former case, high angle α grain boundaries appear in the early stages of compressive deformation at 1173 K under a strain rate of 1.1×10−3 s−1, due to local recrystallization of α subgrains. Misorientation angles among the α grains increase with increasing compressive deformation. Such a microduplex structure with high angle grain boundaries is presumed to be responsible for superplastic deformation at the high temperature. In the latter case, the recovery in the α matrix and the precipitation of the γ phase occur simultaneously, during compressive deformation at 1173 K under a strain rate of 2.2×10−2 s−1. Since the specimen deforms heterogeneously, in the areas where large strain is stored the recovery occurs rapidly and the ultra-fine α subgrains are formed during hot compressive deformation. Then, at those sub-boundaries, γ particles predominantly nucleate. Consequently, an ultra-fine microduplex structure with average grain size of 0.5 μm is formed.抄録全体を表示PDF形式でダウンロード (2379K) -
近藤 政彰, 浅野 滋1989 年 53 巻 10 号 p. 998-1003
発行日: 1989年
公開日: 2008/04/04
ジャーナル フリーInternal friction was measured at constant temperature as a function of frequency from 10−3 Hz to 10 Hz in austenitic stainless steel charged with hydrogen. A relaxation peak due to hydrogen was detected in the frequency dependence of internal friction measured around 200 K, where such a peak has not yet been reported. This peak apparently corresponded to the well-known hydrogen peak found so far in the temperature dependence of internal friction. The activation energy of the hydrogen peak was estimated by the peak-shift method to be 53.7 kJ/mol, which agrees well with the activation energy of hydrogen diffusion in austenitic stainless steel.
Hydrogen-charging was carried out by the electrolytic method and also by the gas-equilibration method. Both the methods always produced a hydrogen peak of internal friction, although the austenitic phase transformed partially to a hydrogen-induced εH phase by the former method but not at all by the latter method. Therefore, the hydrogen peak was not associated with any hydrogen-induced transformation. This fact leads to the conclusion that the hydrogen peak is caused by dissolved hydrogen in the fcc lattice of austenitic stainless steel and it may probably originate from the stress-induced ordering of hydrogen atom pairs or clusters.抄録全体を表示PDF形式でダウンロード (811K) -
竹元 嘉利, 飛田 守孝, 助台 栄一, 原 精1989 年 53 巻 10 号 p. 1004-1012
発行日: 1989年
公開日: 2008/04/04
ジャーナル フリーA change of deformation modes in lattice instable Ti-14 mass%Mo alloy single crystals ((\bar110) plate and (\bar3\bar31) side) upon aging treatments at 623 K was investigated in the tensile test up to rupture. The tensile direction of these specimens was [116]β. The main deformation modes of as-quenched specimen (AQ) were {332}⟨113⟩ and {112}⟨111⟩ mechanical twins. Their Schmid factors (SF) were 0.321 and 0.156 in {332}⟨113⟩ twins and 0.447 in {112}⟨111⟩ twins. A specimen aged for a short time of nearly 250 s (AG(S)) showed a kind of transitional state of deformation mode which involved {332}⟨113⟩ twins, {112}⟨111⟩ twins and {112}⟨111⟩ slips. In this state AG(S) had been already poor in ductility. A specimen long aged for 1×105 s (AG(L)) showed a remarkable brittle fracture caused by the aged ω phase, but it was not the {001} cleavage fracture. The fracture surface had a chevron pattern induced by the operation of some {112} slip systems in the initial stage. Large grown aged ω variants caused the β matrix to remarkably increase the stress level for deformation and induced locally an ω→β inverse transformation. Local softening which occurred with the inverse transformation led to an extreme stress concentration and then to crack. In this way AG(L) apparently showed notable embritlement.抄録全体を表示PDF形式でダウンロード (2596K) -
田 文懐, 佐野 毅, 根本 実1989 年 53 巻 10 号 p. 1013-1021
発行日: 1989年
公開日: 2008/04/04
ジャーナル フリーOptimum alloy compositions and heat treatments to obtain fine dispersion of disordered γ particles in an L12 ordered γ′-Ni3(Al, Ti), and the morphology change of γ precipitates during aging have been investigated by means of transmission electron microscopy.
A uniform solid solution of γ′-L12 ordered phase supersaturated with Ni can be obtained by solution annealing in a suitable temperature range. The γ′ phase hardens appreciably by the fine precipitation of disordered γ. The shape of γ precipitates formed during aging is initially spherical or round-cubic and grow into platelets as aging proceeds. High resolution electron microscopy revealed that the γ precipitates are perfectly coherent with the matrix γ′ as long as the γ-precipitates are plates. The loss of coherency initiates by the introduction of dislocations at the γ⁄γ′ interface followed by the step formation at the dislocations. The γ precipitates become grobular after the loss of coherency.
The chemical compositions of the matrix and the precipitates have been determined by means of EDS microanalysis in an analytical electron microscope. The sense and magnitude of misfit between the γ′ matrix and γ precipitates are determined from the spacings of misfit dislocations and the chemical compositions of γ and γ′ phases.抄録全体を表示PDF形式でダウンロード (4258K) -
田 文懐, 佐野 毅, 根本 実1989 年 53 巻 10 号 p. 1022-1028
発行日: 1989年
公開日: 2008/04/04
ジャーナル フリーMorphology of dislocations in deformed γ′-Ni3(Al, Ti) single crystals containing fine dispersion of disordered γ particles has been investigated by means of weak beam dark field transmission electron microscopy. Superlattice dislocations dissociate into fourfold Shockley partial dislocations in a uniform supersaturated solid solution of the γ′ phase. Dislocations are attracted into the disordered γ phase and dissociate further in the particles. At any stage of aging, dislocations cut through the particles and the Orowan bypassing process dose not occur even in the overaged stage of this alloy system. The work necessary to pull the dislocation away from the disordered particles into the ordered matrix should mainly contribute to increase the strength of the γ′ phase containing fine dispersion of the disordered γ phase.抄録全体を表示PDF形式でダウンロード (1572K) -
田 文懐, 佐野 毅, 根本 実1989 年 53 巻 10 号 p. 1029-1034
発行日: 1989年
公開日: 2008/04/04
ジャーナル フリーStrengthening mechanisms in an ordered intermetallic compound containing coherent precipitates of lower antiphase boundary energy than the matrix have been investigated on the basis of the interaction between deformation induced dislocations and disordered precipitates in an L12 ordered Ni3(Al, Ti). Extra work necessary to pull out the dislocations from the precipitate is dependent on the difference in antiphase boundary energy between the matrix and the precipitate, the size and volume fraction of the precipitate.
The strength of γ′-Ni3(Al, Ti) L12 ordered phase containing fine precipitates of the disordered γ phase has been examined using the proposed model. The model can explain almost quantitatively the age hardening behavior of the ordered Ni3(Al, Ti) phase.抄録全体を表示PDF形式でダウンロード (854K) -
平井 伸治, 三輪 哲也, 岩田 努, 小澤 正義, 片山 博1989 年 53 巻 10 号 p. 1035-1040
発行日: 1989年
公開日: 2008/04/04
ジャーナル フリーExperiments were made of the synthesis of AlN by reduction of Al2O3 with graphite powder in flowing N2 atmosphere at various temperatures between 1773 and 1973 K. At temperature below 1823 K, a temporary rise in the reaction rate was observed near the reaction degree of 50%. This discontinuous change was reflected in the residual carbon and AlN contents. At 1973 K, a small quantity of aluminum oxynitride was formed in the early stage of reaction. The reaction rate was hardly affected by the grain size of graphite, the pellet diameter and the flow rate of N2 gas. The examination of these results led to the conclusion that the diffusion of the reaction gas through the AlN layer formed around the Al2O3 grain is a major rate-determining step. Indeed, the reaction rate obeyed the rate equation which contains only the resistance of intraparticle diffusion.抄録全体を表示PDF形式でダウンロード (787K) -
平藤 哲司, 須山 健, 真嶋 宏1989 年 53 巻 10 号 p. 1041-1046
発行日: 1989年
公開日: 2008/04/04
ジャーナル フリーThe stability of the liquid surfactant membrane consisting of tri-n-octylamine (TNOA), Span 80 and kerosene as an extractant, surfactant and diluent, respectively, was investigated at mainly 298 K. Emulsions were prepared by extensive mixing of the organic solution with the internal aqueous solution containing 3 mol dm−3 H2SO4 or 1 mol dm−3 HCl using a homogenizer at ambient room temperature. The resultant emulsion was then dispersed in the 1 mol dm−3 H2SO4 aqueous solution with an impeller. The breakdown rate of emulsions was measured using a tracer technique to estimate the stability of liquid membrane when emulsions were dispersed in the external aqueous solution. The stability of emulsions increased with an increase in the rotating speed of the homogenizer or in the mixing time for emulsification. The increase in Span 80 concentration and the decrease in TNOA concentration caused an increase in the stability of emulsions. The breakdown rate of emulsions increased with an increase in the rotating speed of the impeller and with an increase in the temperature of the external solution. The apparent activation energy for the breakdown of emulsions was approximately 60 kJ mol−1. A small droplet size of the internal aqueous phase in W/O emulsions and a narrow distribution of the droplet size were desirable for the stabilization of emulsions. However, the droplet size was not always the determining factor of emulsions stability if the droplet size was smaller than a critical value.抄録全体を表示PDF形式でダウンロード (1440K) -
山根 政博, 滝内 直祐, 田崎 義英, 溝口 数一1989 年 53 巻 10 号 p. 1047-1053
発行日: 1989年
公開日: 2008/04/04
ジャーナル フリーThe viscosities of MeO (MeO=Li2O, Na2O, CaO, SrO)-SiO2-Y2O3 silicate melts were measured in order to investigate the behaviour of Y2O3 in the silicates. The results indicate that Y2O3 plays a role as an amphoteric oxide as Al2O3 in the silicate melts and the viscosities measured in this study were well arranged using the following parameter (Pη) which was introduced in the ternary silicate systems containing Al2O3 or Ga2O3 to explain the amphoteric behaviour of those oxides in the silicates.
The parameter Pη is expressed by
(This article is not displayable. Please see full text pdf.)
\ oindentwhere ZMe is the electric charge of Me ion, ni is the ion fraction of i ion and XY is the ratio of tetrahedrally coordinated Y3+ ions to total Y3+ ions.
The XY values of Li2O, Na2O, CaO and SrO systems were calculated to be 0.32, 0.45, 0.36 and 0.41, respectively. Since these values showed about half of those XAl in the same silicate systems, it was clarified that Y2O3 was more basic than Al2O3.抄録全体を表示PDF形式でダウンロード (825K) -
須佐 匡裕, 篠原 秀幸, 永田 和宏, 後藤 和弘1989 年 53 巻 10 号 p. 1054-1061
発行日: 1989年
公開日: 2008/04/04
ジャーナル フリーSilicon substrates were oxidized in an O2/Br2 ambient. In the initial stage of the oxidation, the rate was slower than that of the conventional oxidation. In the course of the O2/Br2 oxidation, however, the rate was gradually accelerated.
The oxidation reaction was analyzed on the basis of the mixed control model of the diffusion of oxygen in the SiO2 film and the chemical reaction at the SiO2/Si interface. The linear rate constant, kL was smaller and the parabolic rate constant, kP was larger in comparison with those of the conventional oxidation, respectively. But the activation energies were almost the same as the conventional ones.
SIMS (Secondary ion mass spectroscopy) and FT-IR (Fourier transform infrared spectroscopy) were employed. The bromine in the SiO2 films existed near the oxide films as Si-Br bonds.
The above results led to the following conclusion. In the initial stage, the Si-Br bonds formed at the SiO2/Si interface reduced the number of the SiO2 production sites, which retarded the oxidation rate. On the other hand, the Si-Br bonds in the SiO2 films increased the numbers of the solubility- and the diffusion-sites of oxygen in the SiO2 films, resulting in the acceleration of the oxidation rate, in the course of the process.抄録全体を表示PDF形式でダウンロード (1159K) -
大野 悟, 宇田 雅廣1989 年 53 巻 10 号 p. 1062-1067
発行日: 1989年
公開日: 2008/04/04
ジャーナル フリーIn order to establish the stabilizing condition of ultrafine metal particles, the oxidizing behavior of fresh ultrafine particles (UFP) of nickel and chromium (average diameters: 40 and 60 nm) prepared by the “hydrogen plasma-metal” reaction has been studied under various oxygen partial pressures below about 700 Pa (PO2+PAr=0.1 MPa) at room temperature (298±2 K).
The most favorable treatment conditions for the stabilizing of the Ni- and Cr-UFP were to oxidize for 12∼15 and 18∼24 ks, respectively, under the oxygen partial pressure of about 100 Pa. Then, the thicknesses of oxide films formed on the Ni- and Cr-UFP by the above treatments were calculated to be 0.8∼1.0 and 1.0∼1.5 nm by assuming the oxide film to be NiO (cubic structure) and Cr2O3, respectively. It was found that the oxidation process of the Ni- and Cr-UFP under oxygen partial pressures below about 700 Pa followed a rate law of the 1.5 power.抄録全体を表示PDF形式でダウンロード (974K) -
今井 義一, 田中 義和, 市川 宏, 石川 敏功1989 年 53 巻 10 号 p. 1068-1076
発行日: 1989年
公開日: 2008/04/04
ジャーナル フリーAlthough MMC is generally expected as a high temperature, structural material of the tensile strength of the SiCPCS/pure Al preform wires shows a decrease about 10% at a high temperature of 723 K. Compared with its room-temperature tensile strength.
For the purpose of increasing the high temperature tensile strength, a Ni-added Al-base binary alloy, which is unidirectionally solidified eutectic alloy, was used as the matrix. Ni contents tested were from 0.5 to 9.2 mass%. When the Ni content was 5.7 mass%, which was the eutectic point, the preform wire with best performance was obtained. The SiCPCS/Al-5.7 mass%Ni preform wire was 1.69 GPa in tensile strength both at room temperature and at 723 K. In the matrix, Al-Al3Ni eutectic phases containing very fine fibrous Al3Ni were observed.
It was considered that the effect of Ni additions made the matrix an “in-situ” composite, prevented high temperature softening and maintained the matrix strength sufficient for stress dispersion. As the result, we have considered that a high tensile strength of SiCPCS/Al-5.7 mass%Ni preform wires may be maintained even at high temperatures.抄録全体を表示PDF形式でダウンロード (2509K) -
平岡 裕, Kuo C. L., Bilello J. C.1989 年 53 巻 10 号 p. 1077-1078
発行日: 1989年
公開日: 2008/04/04
ジャーナル フリーPDF形式でダウンロード (220K)
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