巻号一覧
48 巻, 1 号
選択された号の論文の18件中1～18を表示しています
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屋久 四男, 佐野 毅, 美浦 康宏, 根本 実1984 年 48 巻 1 号 p. 1-7
発行日: 1984年
公開日: 2008/04/04
ジャーナル フリーInterface dislocations between γ-nickel rich solid solution and γ′-L12 ordered phase in a directionally solidified Ni-Al-Ti eutectic alloy have been investigated by transmission electron microscopy. Two types of interface dislocations, one lying parallel to ⟨110⟩ and the other lying parallel to ⟨100⟩ in the interface, are formed surrounding the γ plates. The Burgers vectors of these misfit dislocations are of the a⁄2 ⟨110⟩ type, and they do not lie in the interface but are inclined 45° to the interface. Dislocations gliding on {111} in the γ plate leave paired misfit dislocations parallel to ⟨110⟩ at the γ⁄γ′ interface. Slip and climb movements of dislocations in the γ plate form the misfit dislocations parallel to ⟨100⟩ at the interface. The lattice misfit between γ and γ′ phases was estimated to be 0.15%, from the spacings of the misfit dislocations and their Burgers vectors.抄録全体を表示PDF形式でダウンロード (3246K) -
池田 英幸, 松田 日出彦1984 年 48 巻 1 号 p. 8-14
発行日: 1984年
公開日: 2008/04/04
ジャーナル フリーThe processes of cluster formation at the early stages of aging have been studied by the Monte Carlo method. The investigation was carried out with an assumption of the constant vacancy concentration during aging. Effects of aging temperature and of concentration of solute atoms on clustering were investigated. The configurations of solute atoms with time evolution were also analized by means of pair-correlation functions of solute atoms and its Fourier transform. The results of Fourier analysis showed that the feature of clustering in the vicinity of a spinodal region was like a spinodal decomposition even in the outside of the region.抄録全体を表示PDF形式でダウンロード (1424K) -
末吉 秀一, 末永 勝郎, 田中 良平1984 年 48 巻 1 号 p. 15-20
発行日: 1984年
公開日: 2008/04/04
ジャーナル フリーYield stress, tensile strength and ductility of hypo-eutectoid graphitic steels were studied in connection with microstructural factors such as ferritic grain size dF, volume fraction of graphite f, mean graphite nodule diameter dG, and mean ferrite path between graphite nodules λ.
The graphitic steel containing graphite nodules in ferrite grain boundaries exhibited a yield point clearly, and the yield stress was found to depend on both factors dF−1⁄2 and λ−0.223, while the steel containing a number of graphite nodules in ferrite grains showed no yield point, and the 0.2% proof stress was nearly constant regardless of f, dF, dG or λ.
The tensile strength of the graphitic steel increased proportionally to dF−1⁄2, but decreased slightly with increasing dG.
Ductile fracture strain was given as a function of lndG and lnλ, or ln[(1−f)⁄f] by using a multiple regression analysis. Thus it was concluded that the ductility of the graphitic steel depends strongly on dG and λ as well as on the volume fraction of graphite.抄録全体を表示PDF形式でダウンロード (1031K) -
田口 收, 飯島 嘉明, 平野 賢一1984 年 48 巻 1 号 p. 20-24
発行日: 1984年
公開日: 2008/04/04
ジャーナル フリーAtomic absorption analysis has been used to study the impurity diffusion of copper in nickel in the temperature range between 1080 and 1613 K. The linear Arrhenius plot of the impurity diffusion coefficient of Cu in Ni has been expressed as follows:
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\ oindentAtomic absorption analysis is found to be useful to measure the penetration profile for the impurity diffusion in metals where suitable radioisotope as a tracer is unavailable or the half-life of radioisotope is very short.抄録全体を表示PDF形式でダウンロード (676K) -
野田 哲二, 貝沼 紀夫, 岡田 雅年1984 年 48 巻 1 号 p. 25-30
発行日: 1984年
公開日: 2008/04/04
ジャーナル フリーThe mechanical properties of polyorystalline molybdenum containing various amounts of oxygen in grain boundaries were studied in order to clarify the effect of oxygen on the brittleness of molybdenum. The mechanical properties were evaluated by tensile and microhardness tests, and the oxygen concentration in grain boundaries was measured by Auger electron spectroscopy. The oxygen concentration in grain boundaries was controlled by changing the heating time of the specimens in an oxidizing atmosphere.
The ductile-brittle transition temperature of oxygen contaminated molybdenum was about 100 K higher than that of unoxidized molybdenum. However, it was not changed by increasing the oxygen concentration in grain boundary to more than about 3 at%. The fracture strength at 77 K decreased with increasing oxygen concentration, and it showed a minimum value at 3 at%. Over the oxygen concentration range investigated, the fracture strength showed a tendency to increase and become constant. From the observation by an electron microscope, a step structure of the grain boundary was found for molybdenum of high oxygen concentration. Such change in grain boundary structure was considered to depress the decrease of fracture strength of molybdenum containing oxygen more than 3 at% in grain boundaries.抄録全体を表示PDF形式でダウンロード (1338K) -
野田 哲二, 貝沼 紀夫, 岡田 雅年1984 年 48 巻 1 号 p. 30-35
発行日: 1984年
公開日: 2008/04/04
ジャーナル フリーThe desorption behavior of oxygen from grain boundaries of polycrystalline molybdenum during vacuum annealing at temperatures between 1423 and 1743 K was studied by Auger Electron Spectroscopy (AES). Furthermore, the relation between the deoxidation behavior and the recovery in the ductility of molybdenum was examined. The following conclusions were made.
(1) The grain boundary diffusivity of oxygen in the molybdenum, D was given as D(m2⁄s)=7.8×10−3exp{−(270kJ/mol)⁄RT}.
(2) The ductility of the molybdenum at room temperature was improved, when the oxygen concentration in grain boundaries was reduced to around 1 at%.
(3) The oxygen diffusivity derived from the measurement of the ductility change very closely agreed with that obtained by the AES measurement.抄録全体を表示PDF形式でダウンロード (805K) -
吉永 日出男, 松尾 悟, 栗下 裕明1984 年 48 巻 1 号 p. 35-42
発行日: 1984年
公開日: 2008/04/04
ジャーナル フリーIn order to investigate the origin of internal stress in a solution-hardened alloy deformed at high temperatures, the internal stress and dislocation density have been simultaneously determined by a stress change test during creep deformation at high temperatures. It is found that a unique relation,
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\ oindentholds in the temperature range used whether the creep is in a steady state or not. \barσi in this relation is the internal stress, ρ is the dislocation density, G is the shear modulus, and b is the magnitude of the Burgers vector. From this relation, it is concluded that the origin of internal stress is the long range stress field of forest dislocations.抄録全体を表示PDF形式でダウンロード (1211K) -
山口 周, 後藤 和弘1984 年 48 巻 1 号 p. 43-49
発行日: 1984年
公開日: 2008/04/04
ジャーナル フリーThe activity of Na2O referred to its pure liquid state in Na2O-SiO2-P2O5 ternary melt has been determined by the EMF method constructing galvanic cell, using sodium beta-alumina as a solid electrolyte, written as;
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\ oindentMeasurements of EMF were carried out in the composition range of higher Na2O mole fraction region than conjective line between Na2O·P2O5 and SiO2, at T=1173-1673 K. Na2O-SiO2-Fe2O3 melts were employed as a reference melt, after Na2O activity in these melts was determined by the same method using Na2CO3(l)+CO2(g)+O2(g) as a reference. A determined value of Na2O activity in Na2O-P2O5 melt of XNa2O=0.5 was about 10−13 at 1573 K and was nearly 8 times as small in the order of magnitude as that in Na2O-SiO2 system at the same temperature and Na2O mole fraction.
\ oindentEstimated iso-activity lines of Na2O in Na2O-SiO2-P2O5 ternary melt were drawn almost parallel to the conjective line between Na2O·P2O5 and SiO2, and the density of the lines became higher, as XNa2O became higher. The activities of SiO2 and P2O5 in the system were calculated by integrating Gibbs-Duhem equation by means of Schuhmann, using estimated thermodynamic value, and the iso-activity lines of SiO2 and P2O5 were suggested.抄録全体を表示PDF形式でダウンロード (907K) -
中井 弘, 岡田 健, 白井 秀樹1984 年 48 巻 1 号 p. 50-56
発行日: 1984年
公開日: 2008/04/04
ジャーナル フリーThe corrosion of nickel in various Ar-O2-SO2 atmospheres was studied at 823-1223 K. The scale structure was examined by X-ray diffraction, optical microscope and electron probe microanalysis.
Generally the reaction kinetics was complex and classified into 2 groups depending on the temperature range. This complexity was considered to be due to the difference in scale structure. NiO and Ni3S2 were identified as corrosion products.
The amount of corrosion of nickel decreased to less than one sixth of that without O2 gases in the atmosphere. This effect was considered to be due to the preferential growth of oxide scale by an addition of oxygen into an Ar-SO2 atmosphere.抄録全体を表示PDF形式でダウンロード (2235K) -
松井 具悟, 恵羅 彰男1984 年 48 巻 1 号 p. 57-63
発行日: 1984年
公開日: 2008/04/04
ジャーナル フリーThe catalytic effect of dodecylbenzensulfonic acid (DBSA) on the rate of aluminum extraction with 2-ethylhexyl phosphonic acid mono-2-ethylhexyl ester (DEHEHP) in a paraffin solvent (DOSB) was studied at 298 K. Since DBSA is a strong surface active agent, 1.3 kmol/m3 of 2-ethylhexanol was added to the organic solution as a modifier. The initial aluminum concentration in the aqueous solution was 0.002 kmol/m3. The organic and the aqueous solutions were mixed in a conical flask and shaked in a water bath.
Aluminum was extracted in the region above pH 0.5. The distribution coefficient, the ratio of aluminum concentration in the organic phase to that in the aqueous phase, was found to be propotional to [DEHEHP]o2[DBSA]o/[H+]w3. The rate of aluminum extraction was found to be propotional to [Al]w[DBSA]o2/[H+]w2, but did not show any significant dependence on DEHEHP concentration in the organic phase.
The addition of DBSA increased the rate of aluminum extraction by 100-500 times, i.e, it took only 0.3-1.2 ks (5-20 min) to get the equilibrium state for the solution of 0.5 kmol/m3 DEHEHP, 0.01 kmol/m3 DBSA and 1.3 kmol/m3 2-ethylhexanol in DOSB, whereas it took more than 0.36 Ms (100 h) to reach the equilibrium for the solution of 0.5 kmol/m3 DEHEHP in DOSB without DBSA.抄録全体を表示PDF形式でダウンロード (921K) -
本田 忠敏1984 年 48 巻 1 号 p. 63-70
発行日: 1984年
公開日: 2008/04/04
ジャーナル フリーThe fatigue strength of carbonyl iron compacts sintered at a temperature in the ferrite and austenite ranges and the intergranular fracture observed in the fatigue test were investigated.
The results are as follows:
(1) At the same compacting pressure, the fatigue strength of carbonyl iron compacts sintered for 3.6 ks in the temperature range between 1073 K and 1423 K is higher in ferrite and lower in austenite field.
The endurance limit ratio obtained is in the range between 0.41 and 0.47.
(2) The fatigue strength of specimens sintered isothermally at 1123 K and 1423 K increases gradually with the increase in the sintering time, except that of specimen sintered for 172.8 ks at 1123 K remarkably decreases.
(3) The mode of fatigue fractured surface for specimens sintered at 1123 K is a mixed trans- and intergranular fracture type, while that for specimens sintered at 1423 K is mainly a trans-granular fracture type.
The degree of intergranular fracture increases with the increase in the sintering time at 1123 K and with the decrease in carbon content.抄録全体を表示PDF形式でダウンロード (2334K) -
稲数 直次, 山本 久, 石尾 雅昭1984 年 48 巻 1 号 p. 71-78
発行日: 1984年
公開日: 2008/04/04
ジャーナル フリーIn order to study the formation of the deformation and transformation textures during drawing at room temperature, the amount of strain-induced martensite has been estimated from the X-ray diffraction intensity and hardness, and the changes in the fiber axis during drawing have been investigated by means of the pole figure determination and electron diffraction.
The orientation relationship in γ-α′ transformation induced by drawing was found to coincide with the K-s relation, that is {111}γ\varparallel{110}α′ and ⟨110⟩γ\varparallel⟨111⟩α′.
In the case of 18Cr-8Ni steel, the amount of strain-induced martensite (α′) increases markedly by drawing over 30% reduction. The preferred orientation of austenite is of the ⟨111⟩ fiber axis, while that of martensite is of the ⟨210⟩ fiber axis which rotates toward the ⟨110⟩ axis after drawing to higher reductions.
In the case of 17Cr-12Ni steel, the strain-induced martensitic transformation (γ→α′) does not occur. The texture of austenite consists of the ⟨111⟩ fiber axis and the minor orientations of the ⟨511⟩ axis as a twin component and the ⟨100⟩ axis rotated from ⟨511⟩.
In the case of 18Cr-10Ni-3Cu steel, the strain-induced martensitic transformation is detected after drawing over 50% reduction in area. At lower reductions, the ⟨111⟩ fiber axis is developed covering a wide area of austenite, and simultaneously mechanical twins are formed. At higher reductions, the gtrain-induced martensitic transformation occurs both in the matrix and in the twin bands. The fiber axis of the texture transformed from the twin component is ⟨100⟩α′.抄録全体を表示PDF形式でダウンロード (1457K) -
神尾 彰彦, 手 裕康, 熊井 真次, 高橋 恒夫1984 年 48 巻 1 号 p. 78-83
発行日: 1984年
公開日: 2008/04/04
ジャーナル フリーAl-17.5 mass%In alloys of monotectic composition were solidified unidirectionally at various growth rates and temperature gradients, and monotectic solidification structures were observed. Solidification conditions of alloys were measured by the use of 3-4 sets of C. A. thermocouples which were inserted into a mold cavity. In the present work, growth rates and temperature gradients changed over ranges from 2.8×10−7-1.11×10−2 m/s and from 500-8500 K/m, respectively.
When a temperature gradient was constant, the microstructure changed in the sequence, fibrous composite structure→periodical and regular array of L2(In) droplets→random dispersion of L2 droplets, in the aluminum matrix with increasing growth rate. The critical growth rate to form regular composite structures increases as the temperature gradient increases. The monotectic composite structure, i.e., the regular arrangement of L2 fibers or L2 droplets in the aluminum matrix was obtained at the G⁄R values more than 109 K·s/m2. The inter-fiber spacing (λ) of L2 was related to growth rates (R) by λ=KR−1⁄2 which was a common relationship among many lamella or rod eutectic composite structures, K being 2.8×10−8 m1.5 s−0.5.抄録全体を表示PDF形式でダウンロード (3467K) -
神尾 彰彦, 手 裕康, 熊井 真次, 高橋 恒夫1984 年 48 巻 1 号 p. 84-90
発行日: 1984年
公開日: 2008/04/04
ジャーナル フリーAl-17.5 mass%In alloys of monotectic composition were solidified unidirectionally at various growth rates and temperature gradients, and were quenched during growth to observe the solid-liquid interface morphology. The morphology of Al solid phase and the dispersion behavior of L2 phase at monotectic growth front were examined, and the formation manner of regular monotectic composite and its structural transition were discussed. Fibrous composite structures were held in the neighborhood of monotectic temperature for various time durations, and the thermal stability of L2 fibers was examined.
When fibrous composite structures were obtained, the solid-liquid interface was generally planar and some projection of L2 phase toward L1 phase was observed. At about 109 K·s/m2 of G⁄R, periodical perturbation of the growth front and liquid depressions formed, and conical glass-like L2 droplets were incorporated into an aluminum matrix intermittently. These conical glass-like L2 droplets were spheroidized during the cooling process to form regular arrays of spherical L2 droplets. Below 109 K·s/m2 of G⁄R, the solid-liquid interface was no longer planar, and regular monotectic composite structures could not be formed. Droplet composite structures were also formed by necking down, pinching off and spheroiffizing of L2 fibers during the cooling process at relatively high temperature below the monotectic temperature. As the diameter of L2 fibers decreased, i.e., as growth rates increased, this structural transition during cooling was enhanced.抄録全体を表示PDF形式でダウンロード (2554K) -
遠藤 隆士, 河上 護1984 年 48 巻 1 号 p. 91-96
発行日: 1984年
公開日: 2008/04/04
ジャーナル フリーBoronizing is one of the chemical methods for case hardening of steels. The hardness of the boronized layer exceeds 1400 Vickers hardness, and it has a high resistance, especially, against wear.
In the present study, plane and rotating bending fatigue tests of boronized steels with various thicknesses of boronized layers were conducted. Effects of the thickness of boronized layer on crack initiation and the propagation mechanism were investigated by fatigue crack observation.
The results are summarized as follows:
(1) Many cracks propagating uprightly to the tensile axis and those propagating parallel to the tensile axis along which a boronized layer was spalled, were observed.
(2) Fatigue cracks were observed also in the specimen which was not fractured in cyclic number 107. But all those cracks were arrested either in the boronized layer or a boundary between the boronized layer and the matrix. Fracture was controlled by whether the crack propagated through the boundary or not.
(3) Fatigue strength of boronized specimens consisting of Fe2B uni-layer was better than that of boronized specimens consisting of FeB+Fe2B bi-layer. The maximum fatigue strength was obtained, when the Fe2B boronized area was cantrolled so as to be about 1.5% of the total area.抄録全体を表示PDF形式でダウンロード (1322K) -
田口 悟1984 年 48 巻 1 号 p. 97-103
発行日: 1984年
公開日: 2008/04/04
ジャーナル フリーImproved orientation results in the greater permeability which in turn lowers the core loss. The additional benefit of the greater permeability material is a further decrease in the core loss resulting from a tensile stress imparted by the glass film (forsterite coating) and inorganic insulation coating (S2). In the case of a (110) [001] single crystal, domain observations using scanning electron microscopy indicate a decreasing domain wall spacing with the applied stress. Comparison between two adjacent portions, one with coating and the other without, in a single grain shows the effect of the coating on the domain structure, that is reduction of 180° wall spacings and supression of the supplementary domain structure. A great part of the decrease in core loss with the applied tensile stress or the tensile stress imparted by the coating is believed to be due to the decreased domain wall spacing.
However, the domain structure of large specimens (60 mm×300 mm) observed using the magnetic powder technique, shows that the tensile stress of about 7 MPa is far less effective in reducing the 180° wall spacing, but the domain wall spacing is decreased remarkably by the coating. The glass film imparts about 3 MPa, and the stress coating (S2) imparts about 4 MPa. The stress coating (S2) without the glass film results in the most significant decrease in the 180° wall spacing, and a coating (S) without the glass film is also effective in reducing the domain wall spacing. The tensile stress is not imparted by the coating (S). The domain wall spacing is decreased by an oxidizing annealing in wet hydrogen atmosphere. The tensile stress is not imparted by the oxidized surface film. The stress coating (S2) on the oxidized film is not effective in reducing the 180° wall spacing, when the coating dose not penetrate the oxidized film. With partial removal of the glass film, the core loss is found to increase significantly, but the domain wall spacing increases slightly. Surface roughness is not effective in reducing the domain wall spacing. From these results, the tensile stress applied in the rolling direction or imparted by the coating is effective in lowering the core loss, but not effective in reducing the domain wall spacing. Localized stress imparted by some boundary layer or inclusions lying just below the sheet surface is thought to be effective in reducing the domain wall spacing.抄録全体を表示PDF形式でダウンロード (3326K) -
上原 重昭, 鈴木 敏之, 木村 啓造1984 年 48 巻 1 号 p. 104-112
発行日: 1984年
公開日: 2008/04/04
ジャーナル フリーIn order to clarify the effect of hydrogen on the decomposition of β phase in a Zr-20 mass%Nb alloy, the Zr-20 mass%Nb alloys containing up to 200 ppm of hydrogen were prepared, and the change in microstructure and mechanical property with aging have been investigated.
As for the aging behavior, both the time required to start age hardening and the time required to obtain the maximum hardness become longer, as the hydrogen content increases. When the alloy is aged at temperatures below 773 K, the decomposition process is not affected by the addition of hydrogen. However, when the alloy is aged at 823 K, though only continuous precipitation occurs in the alloy without hydrogen, discontinuous precipitation occurs with the continuous one in the alloy containing 200 ppm hydrogen.
Microstructures of the alloy at the solution treated condition was not affected by the addition of hydrogen. However, during aging ω and α particles precipitated are coarsened by the existence of hydrogen. When the alloy containing 200 ppm of hydrogen is aged at 823 K, the microstructure changes from a globular type to a nodular type because of the change in precipitation mechanism in the alloy.
As the content of hydrogen increases, the hardness and tensile strength decreases. No deterioratxon in toughness was observed throughout this experiments.抄録全体を表示PDF形式でダウンロード (4728K) -
中谷 義三, 大西 忠一, 東 健司1984 年 48 巻 1 号 p. 113-114
発行日: 1984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 (1059K)
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