巻号一覧
47 巻, 12 号
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増田 順一1983 年 47 巻 12 号 p. 1023-1028
発行日: 1983年
公開日: 2008/04/04
ジャーナル フリーMeasurements of acoustic emission during yielding of a metal, relating with its internal structure, have not been sufficiently carried out. It is a purpose of the present study to clarify the properties of acoustic emission generated in tensile test of a Cu-Co alloy, which is known as an age-hardening alloy with coherent precipitates and to discuss the acoustic emission characteristics relating with its each precipitating stages as well as deformation characteristics.
(1) At the stages of solution treatment and precipitating of coherent particles, acoustic rms voltage and amplitude distribution in tensile test are similar to those of pure copper. The reason is that the lattice constant of the solute Co lattice is almost the same as that of the solvent Cu lattice. (2) For the Ostwald growth stage of precipitated particles, rms voltage takes a maximum, when the stress-crosshead displacement curve bends sharply. This behavior is similar to the result of computer simulation of acoustic emission during yielding of a dispersion hardened alloy with precipitates of different strengths reported previously. Amplitude of acoustic pulses increases with increasing yield stress. The mean energy of acoustic event is proportional to r3.5/l2, where r is the mean radius of the particle, and l is the mean distance between two neighboring particles. (3) At the over-aged stage caused by particle size increment, rms voltage in tensile test is smaller than that at the Ostwald growth stage. The high amplitude pulses, which are generated for the Ostwald growth stage, are not observed.抄録全体を表示PDF形式でダウンロード (1051K) -
羽木 秀樹1983 年 47 巻 12 号 p. 1029-1035
発行日: 1983年
公開日: 2008/04/04
ジャーナル フリーThe diffusion of hydrogen in nickel and copper, and in fcc nickel-copper and nickel-cobalt alloys has been investigated within the wide temperature range from 260 K to 1000 K by a technique of electrochemical permeation and a technique of gas phase permeation. The temperature dependence of the diffusion coefficient of hydrogen (D) in Ni and Cu is described as follows: In Ni, D (m2/s)=9.2×10−7exp(−41.4 (kJ/mol)/RT), and in Cu, D (m2/s)=9.2×10−7 exp(−43.5 (kJ/mol)/RT). Plots of the experimentaly observed logD versus 1/T in Ni-Cu and Ni-Co alloys can be represented by straight lines. The activation energy for diffusion of hydrogen changes with the concentration of alloying element. It has a maximum at 70 at%Cu in Ni-Cu alloys, and increases with increasing concentration of Co in Ni-Co alloys.
The solubility of hydrogen (S) in Ni, Cu, Ni-Cu alloys and Ni-Co alloys has been measured by a gas phase permeation method at temperatures between 560 K and 1000 K. The temperature dependence of S in Ni and Cu is given by S (mol H2/(mol Ni·Pa1⁄2))=2.2×10−6exp(−10.8 (kJ/mol)/RT) in nickel and S (mol H2/(mol Cu·Pa1⁄2))=1.4×10−5exp(−37.6 (kJ/mol)/RT) in copper. Arrhenius plots of S in Ni-Cu and Ni-Co alloys can be represented by straight lines. The solution enthalpy of hydrogen has a minimum at 30 at%Cu in Ni-Cu alloys, and increases with increasing concentration of Co in Ni-Co alloys.抄録全体を表示PDF形式でダウンロード (901K) -
橋本 健紀, 土肥 春夫, 辻本 得蔵1983 年 47 巻 12 号 p. 1036-1041
発行日: 1983年
公開日: 2008/04/04
ジャーナル フリーStructures of Ti-Al-Ag alloys have been examined by means of electron probe microanalysis, X-ray diffractometry, scanning electron microscopy and differential thermal analysis. An isothermal diagram at 1073 K and a vertical diagram section through Ti-51.0 at%Al and Ag-7.5 at%Al line are shown in this paper.
(1) Phases (crystal structure) encountered are as follows: TiAl3(D022), TiAl(L10), Ti3Al(D019), (α-Ti) (A3), Ti3Ag(L10), TiAg(L10) and (Ag) (Al).
(2) The intermetallic compounds TiAl3, TiAl and Ti3Al are in equilibrium with the (Ag) phase containing about 0.6 at%Ti and 2-15 at%Al.
(3) Maximum solubilities of silver in the TiAl3, the TiAl and the Ti3Al phases are about 15 at%, 3 at% and 2 at%, respectively. Solute silver atoms mainly substitute for aluminium atoms in the TiAl3 or the TiAl phases and for both titanium and aluminium atoms in the Ti3Al. In the intermetallic compounds TiAg or Ti3Ag maximum solubility of aluminium is 1 at%, and aluminium atoms mainly substitute for silver atoms.
(4) The vertical diagram section shows that the TiAl phase constructs a pseudo-binary system with the (Ag) phase. Reaction temperature of TiA1+(Ag)→TiAl+(Ag)+L rises slightly with an increase in silver content, though it is located near the reaction temperature of TiAl+(Ag)+L→TiAl+L. Solubility of silver in the TiAl phase decreases linearly above 1113 K and keeps a constant value of about 2.4 at% under 1073 K. The (Ag) phase contains about 8 at%Al and 0.6 at%Ti under 1073 K.抄録全体を表示PDF形式でダウンロード (1940K) -
井口 義章, 福永 光成, 平尾 次郎1983 年 47 巻 12 号 p. 1042-1047
発行日: 1983年
公開日: 2008/04/04
ジャーナル フリーIt was tried by observing partially reduced pellets microscopically and by analysing reduction rates to elucidate the mechanism for Al2O3 to accelerate the reduction of wustite produced from magnetite containing Al2O3. A macroscopical cross section view of partially reduced pellets of 50% reduction indicates that the reduction pattern is of homogeneous type except the one at 1203 K. Furthermore, the microscopical observation displays that wustite grains are covered by a dense layer of metallic iron and that the mean radius of residual wustite grains decreases with an increase in the amount of Al2O3. On the other hand, a graphical analysis of reduction rate shows that the rate is controlled by the diffusion of oxygen in a metallic iron layer covering wustite grain. From the above mentioned results, it is concluded that the effect of Al2O3 may cause the formation of the dense iron layer covering the wustite grain thoroughly, but it can accelerate the reduction by dividing a wustite grain into smaller many ones.抄録全体を表示PDF形式でダウンロード (1407K) -
藤重 昌生, 横川 晴美, 亀山 哲也, 氏家 誠一, 本江 秋弘, 福田 健三, 土器屋 正之1983 年 47 巻 12 号 p. 1047-1054
発行日: 1983年
公開日: 2008/04/04
ジャーナル フリーIn order to elucidate the behavior of Si and Al compounds in an aluminum blast furnace, the carbothermic reduction of alumina and other additives was carried out under CO gas flow in an electric furnace which simulated the reduction zone of blast furnace. In the cases of alumina-silica and alumina-silicon systems, a solid “bridge” was formed with the volatilized gaseous species, whereas no bridge was formed in the case of alumina-silicon carbide system. This bridge was mainly composed of amorphous silica, suggesting that the dominant volatile species is silicon monoxide evolved during the reduction of silica. A bridge was also formed in the case of alumina-calcia system and composed of unknown compounds, containing a small amount of aluminum tetraoxycarbide, which confirmed the volatilization of aluminum monoxide. Alumina was not reduced to aluminum metal in the alumina-calcia system, since alumina was stabilized by forming a complex oxide. In the cases of alumina-iron and bauxite systems, no bridge was formed. The conclusion of the present study is that bauxite with high iron and less silica content will be favorable as raw materials for the aluminum blast furnace.抄録全体を表示PDF形式でダウンロード (1240K) -
松井 眞悟, 恵羅 彰男1983 年 47 巻 12 号 p. 1055-1062
発行日: 1983年
公開日: 2008/04/04
ジャーナル フリーThe extraction rate of aluminum from sulfuric acid solution with 2-ethylhexyl phosphonic acid mono-2-ethylhexyl ester was studied. The two phases in a conical flask were mixed by shaking at 298 K. The initial aluminum concentration in aqueous solution was chosen to be 2 mol/m3, so as to minimize the variation of pH during the extraction reaction. The extractant concentration was changed from 0.1 to 1.5 kmol/m3, and pH was varied from 1.0 to 3.0.
The extraction rate was found to be of the first order with respect to the aluminum concentration in the aqueous phase. A different dependence of the extraction rate on pH and the extractant concentration was observed in the following regions: (1) When pH is below 2 or when the extractant concentration is lower than 0.2 kmol/m3, the extraction rate is of the −1 order of hydrogen ion concentration in the aqueous phase and is of the 0.5 order of the extractant concentration. (2) When pH is above 2 and the extractant concentration is higher than 0.2 kmol/m3, the extraction rate is of the 1.5 order of the extractant concentration, and as the extractant concentration increases, the dependence on the hydrogen ion concentration in the aqueous phase varies from −1.5 to −2.5 order.
Detailed consideration of the experimental results and numerical analysis with computor elucidate that there are three paths in the extraction mechanism of this system. The first pass is expected to be a series of reaction from Al3+ ion and is shown as follows:
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The second one is a path from AlOH2+, as is shown with the following reactions:
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The third path is expected to be the following reaction:
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The rate constants calculated for Al3+ and AlOH2+ are in good agreement with those obtained in hydrochloric acid solution.抄録全体を表示PDF形式でダウンロード (1002K) -
池田 弘幸, 村山 康幸, 大岡 泰人, 森永 健次, 柳ヶ瀬 勉1983 年 47 巻 12 号 p. 1063-1067
発行日: 1983年
公開日: 2008/04/04
ジャーナル フリーThe chemical shifts of SiKα, SiKβ and AlKα have been measured to find out the structure of SiO2 and Al2O3 in glassy states by using a high resolution X-ray fluorescence spectrometer. Correlation between the chemical shift of SiKα and the polymerization degree of silicate anion was indicated by the data of minerals and compounds in which the silicate anion structure is well known. From the above correlation the structure of silicate anion in glassy states may be estimated in terms of the optical besicity of glasses.
The chemical shifts of SiKβ were dependent upon the content of basic oxide and reflected in the Si-O distance. The change in oxygen coordination number of Al3+ ion in glasses have been estimated from the chemical shifts of AlKα and also discussed in terms of the optical basicity of glasses.抄録全体を表示PDF形式でダウンロード (720K) -
大槻 悦夫, 増田 良道1983 年 47 巻 12 号 p. 1068-1074
発行日: 1983年
公開日: 2008/04/04
ジャーナル フリーAn attempt was made to clear up the reason why the relationship between fracture stress and the size of fracture-initiating defect of the cemented carbides (WC-Co alloys and TiC-Ni base alloys) changes at a certain defect-size.
The fracture strain of the cemented carbides depends upon the defect-size similarly to the fracture stress. Irrespective of the defect-size, the fracture crack is always propagated from a pre-existing defect and the critical condition for fracture obeys the Griffith-Irwin criterion. The toughness of the cemented carbides is reduced due to the plastic flow of the binder phase and the fracture toughness KIC is lowered gradually with increase in the applied stress beyond the yield strength. Therefore when the cemented carbides undergo a fracture under a high applied stress, a small variation of the fracture stress with the change of defect-size is obscured by scattering of the experimental data. Consequently, the fracture stress is apparently observed independent of the defect-size and this can be designated as the limiting strength.抄録全体を表示PDF形式でダウンロード (1629K) -
頓田 英機, 長久 正規, 池上 修, 川 獺雄1983 年 47 巻 12 号 p. 1075-1079
発行日: 1983年
公開日: 2008/04/04
ジャーナル フリーThe influence of thermomechanical treatment on electrical resistivity and hardness of Cu-Ni-Si alloys was investigated. Results obtained are summarized as follows: (1) The aging curve of hardness exhibits a hump before a maximum peak, similar to the typical curve of Al-Cu alloys. The biginning of hump corresponds to the maximum peak at the early stage on aging curve of the electrical resistivity. (2) The cold working at the stage of the initial- and over-aging increases the electrical resistivity. The electrical resistivity after working at the stage of the initial aging decreases rapidly and then takes a maximum value with increasing aging time. (3) On the other hand, at the middle stage, at which a number of fine precipitates are formed, the electrical resistivity decreases by the cold working up to 70% reduction area. The electrical resistivity after working increases drastically and then reaches a maximum value with increasing aging time.
The above results on the electrical resistivity were explained by the size distribution change of fine precipitates due to dislocation cutting or promoted precipitation.抄録全体を表示PDF形式でダウンロード (789K) -
猶原 隆, 篠原 和充1983 年 47 巻 12 号 p. 1080-1086
発行日: 1983年
公開日: 2008/04/04
ジャーナル フリーThe electrical resistivity and acoustic emission (AE) were measured simultaneously during a cyclic heat treatment from room temperature either to 973 K or 873 K, in order to study the mechanisms of sigma phase formation in an equiatomic Fe-V alloy. During the holding stage for 432 ks either at 973 K or 873 K, the 973 K specimen produced drastic increase both in the resistivity and the AE event count, but the 873 K specimen produced a considerable amount of AE but a slight decrease in the resistivity. The occurrence of the AE took place not continuously but intermittently during the holding stage at those temperatures. Furthermore, examinations by X-ray analysis and transmission electron microscopy showed that the 973 K specimen consisted entirely of the sigma phase containing many lattice defects, and that the 873 K specimen consisted mainly of the ferrite phase and slightly of the sigma phase which was confined to an extremely thin layer on the free surface.
On the basis of the concept that the AE occurrence and introduction of lattice defects may be restricted to the diffusionless transformation, it was inferred that the cooperative movement of atoms takes part in the sigma phase formation in the equiatomic Fe-V alloy.抄録全体を表示PDF形式でダウンロード (1290K) -
西村 六郎, 佐藤 教男1983 年 47 巻 12 号 p. 1086-1093
発行日: 1983年
公開日: 2008/04/04
ジャーナル フリーThe composition, layer structure and thickness of the passive films formed on iron in borate and phosphate solutions have been examined as functions of pH, potential and film formation procedure (one-step and two-step oxidation) by using electrochemical and ellipsometric techniques.
The ellipsometric measurements of δP-δA curve during galvanostatic-cathodic film reduction show that the layer structure of the passive film changes with pH from an outer barrier layer/an inner barrier layer in acid to a deposit layer/an outer barrier layer/an inner barrier layer in weak acid and to a deposit layer/a barrier layer in neutral and alkaline solutions. The barrier layer consists of two layers in the pH region below pH 5.5, but turns to be a single layer above this pH. The barrier layer thickness increases nearly linearly with potential, but once the overpotential is fixed, it remains constant regardless of pH, anion species and film formation procedure. The deposit layer thickness, which is almost independent of potential, tends to increase with increasing pH up to about pH 8.
Chemical analyses of iron ion dissolved from the film during cathodic reduction show no significant effect on the deposit layer composition (ZFe\fallingdotseq3.00) of pH, anion species, potential and film formation procedure except for a decrease in ZFe at low potentials. The mean oxidation valency of the barrier layer, however, varies from ZFe\fallingdotseq2.33 to ZFe=3.00, depending on pH, anion species, potential and film formation procedure. The results are explained in terms of the ion selective property of the passive film, and the layer structure and composition are summarized in the potential-pH diagrams.抄録全体を表示PDF形式でダウンロード (1097K) -
栗林 宗孝, 岡林 久喜1983 年 47 巻 12 号 p. 1094-1100
発行日: 1983年
公開日: 2008/04/04
ジャーナル フリーAuger spectroscopic analysis and thermodynamical calculations were conducted, in order to determine the chromium concentration profiles near grain boundaries of austenitic stainless steels.
Of several kinds of environmental sensitive cracking of austenitic stainless steels, the intergranular corrosion, the intergranular stress corrosion cracking and the intergranular hydrogen embrittlement were discussed with particular respect to the chromium depletion occurring near grain boundaries.
Results obtained are as follows.
(1) The local chromium concentrations in the chromium depleted zone at grain boundaries could be quantitatively determined by Auger spectroscopic analysis.
(2) The local chromium concentrations in austenite at interface with Cr23C6 particles were calculated by using the chromium and carbon activities. The calculated results were in good agreement with the experimental results.
(3) The intergranular corrosion attack and the intergranular stress corrosion cracking susceptibilities were found to have strong dependence on the minimum chromium concentration in the chromium depleted zone at grain boundaries.
(4) The intergranular hydrogen embrittlement, however, was affected mostly by chromium carbide precipitation and not affected much by the minimum chromium concentration.抄録全体を表示PDF形式でダウンロード (1006K) -
畑山 東明, 岡部 卓治, 武井 英雄1983 年 47 巻 12 号 p. 1101-1107
発行日: 1983年
公開日: 2008/04/04
ジャーナル フリーThe dependence of flow stress on deformation time (strain) is examined under various conditions of the strain rate sensitivity parameter, m, for superplastic Al-Cu and Al-Cu-Si eutectic alloys, and is analized from a kinematical viewpoint. Results obtained are as follows: (1) The period of deformation, T∗0, is expressed as T∗0=2nT∗ (n=…, 1/3, 1/2, 1, 2, 3,…), where T∗ is the time between the onset of the initial elastic deformation and the sub-sequent plastic deformation. (2) The variation in flow stress, Δσ/σ, for a deformation period is approximately expressed as
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\ oindentwhere C is a constant and J=∂m⁄∂ln\dotε. (3) From the above equation, it is expected that for the work hardening parameter, γ≡(1⁄σ)(∂σ⁄∂ε), γ>0, γ=0 and γ<0 when J>0 J=0, and J<0, respectively, and these relations show a good agreement with the experimental results obtained from Al-Cu and Al-Cu-Si eutectic alloys. (4) The value measured by the strain rate change method depends on the strain rate ratio, N. The value within N<10 increases with increasing N when J>0. It decreases with increasing N when J<0. In the case of J=0, it becomes constant. (5) Defining m+ and m− to be the m-value for the increment and decrement in the strain rate, respectively, it is suggested that m+>m− when J>0, m+<m− when J<0 and m+=m− in the case of J=0.抄録全体を表示PDF形式でダウンロード (893K) -
岡部 卓治, 畑山 東明, 武井 英雄, 池田 正人1983 年 47 巻 12 号 p. 1108-1114
発行日: 1983年
公開日: 2008/04/04
ジャーナル フリーThe strain rates in the non-uniform and the uniform portion, Sn and Su, are analyzed from a viewpoint of interaction between Si (i=u, n) and Q which is an element with a given strain rate. The prediction is compared with the experimental results: (1) The magnitude of strain rate deviation, ΔR∗i(=Δ\dotεi⁄\bar\dotε), normalized by a given strain rate, \bar\dotε, in the portion, Si, is expressed as:
(This article is not displayable. Please see full text pdf.)
\ oindentwhere C is a constant, m a strain rate sensitivity parameter, Ai a cross-sectional area in the portion Si, and λi(=li⁄L) a normalized length of Si divided by a specimen length, L. (2) The calculated results agree well with the experimental results, that is, |ΔR∗i| shows a maximum value at a certain length, λ∗i, which becomes smaller with decreasing m-value and |ΔR∗i| decreases with increasing m-value. (3) The length of necking region, which occurs during deformation, increases with increasing m-value, and the growth rate of necking becomes lower as the m-value increases. (4) The interaction force between Q and Si is an attractive force (or a repulsive force), when Δ\dotε and \bar\dotε have the same signs (or different signs), where \bar\dotε and Δ\dotε are a given strain rate and a strain rate deviation of Si from \bar\dotε, respectively.抄録全体を表示PDF形式でダウンロード (988K) -
浅野 稔久, 飯嶋 安男, 伊藤 喜久男, 太刀川 恭治1983 年 47 巻 12 号 p. 1115-1122
発行日: 1983年
公開日: 2008/04/04
ジャーナル フリーEffects of titanium addition to the niobium core on the composite-processed Nb3Sn superconductor have been investigated. Composites consisting of pure niobium or Nb-0.5, 1, 2, 3, 4 at%Ti alloy core and Cu-7 at%Sn alloy matrix were fabricated into a single core and 160-core multifilamentary wires, and then heat-treated to form Nb3Sn layers. An enhanced growth rate of Nb3Sn layer with increasing titanium content has been observed, while the Nb3Sn grain size slightly increases with the titanium addition. The titanium addition of 1-2 at% to the niobium core produces a small maximum in Tc, and further titanium addition decreases it. The addition of titanium to the core increases Hc2 by ∼4 T. An Hc2 of about 25 T has been obtained at 4.2 K by the titanium addition. The Hc2 enhancement has been discussed in relation to the increases of Tc and the normal state resistivity through the titanium addition, and also to the suppression of martensitic transformation in Nb3Sn. Jc’s of Nb3Sn at high fields (H>13 T) are remarkably increased by the titanium addition, which may be due to the enhancement in Hc2. A Jc for Nb3Sn layer, 1.1×109 A/m2, and overall Jc of 2.0×108 A/m2 have been obtained at 4.2 K and 16 T for a single core wire and a 160-core multifilamentary wire, respectively. The Nb-Ti/Cu-Sn composite wire seems to be quite promising for applications in a magnetic field range of 12-16 T at 4.2 K.抄録全体を表示PDF形式でダウンロード (1587K) -
山崎 徹, 荻野 喜清, 富永 充治, 萬條 光秀1983 年 47 巻 12 号 p. 1123-1132
発行日: 1983年
公開日: 2008/04/04
ジャーナル フリーIn order to obtain informations about the effect of oxygen in grain boundaries on intergranular hydrogen embrittlement (IGHE) of nickel, tensile properties and grain boundary surface-cracking of cathodically hydrogen-charged specimens annealed either in vacuum or in dry hydrogen gas were examined. A high susceptibility to IGHE and to grain boundary surface-cracking was observed when annealed in vacuum. While, when annealed in hydrogen, the susceptibility decreased significantly, revealing predominantly a transgranular fracture mode accompanied by a marked local contraction. Such dependence on annealing environments may be ascribed to the penetration of oxygen into grain boundaries during vacuum annealing. The penetration depth of oxygen evaluated from the grain boundary surface-cracking exceeds 2 mm depending on the grain boundry orientation. These observations would have an important implication regarding problems about IGHE of nickel and Ni-base alloys, since the effect of oxygen has so far been disregarded.抄録全体を表示PDF形式でダウンロード (3359K) -
森 信幸, 空野 博明, 北原 晃, 大城 桂作, 松田 公扶1983 年 47 巻 12 号 p. 1132-1139
発行日: 1983年
公開日: 2008/04/04
ジャーナル フリーThe effect of Ca addition on the wettability and the interaction of liquid Al on graphite, Al2O3, and SiO2 substrates has been investigated in the atmosphere of low pressure (0.27-0.67 kPa) H2 gas at temperatures over the range from 973 K to 1123 K by the sessile drop method.
Results obtained are as follows:
(1) The wetting angles between liquid Al and graphite, Al2O3 and SiO2 substrates show a tendency to decrease with 1-2%Ca addition and increasing temperature.
(2) The wetting angles of liquid Al and Al-Ca alloy on graphite substrates decreased with elapse of the wetting time at temperatures above 1123 K. This phenomenon is more remarkable at higher temperatures, and is considered to be due to the formation of Al carbide at the interface.
(3) The wettability of Al2O3 substrate by liquid Al-Ca alloy is almost unchanged by elapse of the wetting time and by the formation of Ca oxide at the interface.
(4) The wettability of SiO2 substrate by liquid Al has the time dependence, which is associated with the formation of significant amounts of interfacial compounds. On the other hand, by liquid Al-Ca alloy the wettability does not have the time dependence, and the formation of compounds is decreased with addition of Ca.抄録全体を表示PDF形式でダウンロード (2071K)
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