巻号一覧
66 巻, 11 号
選択された号の論文の14件中1～14を表示しています
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世利 修美, 渡部 賢, 真保 良吉2002 年 66 巻 11 号 p. 1067-1072
発行日: 2002年
公開日: 2008/04/24
ジャーナル フリーThe standard Gibbs free energy of FeAl3 has obtained to be −58.8 kJ/mol. The electrochemical characteristics has been investigated in terms of occurrence of selective or spontaneous dissolution of components of intermetallic compound phase FeAl3 in a 0.1 kmol/m3 NaCl+0.5 kmol/m3 AlCl3 solution. It is discussed that the existence of approximate value of 10 ppm ferrous ions detected at constant potentials of −0.8 V and −1.2 V vs. Ag/AgCl may attribute to the sequential reactions in the electrochemical processes: selective dissolution of aluminum component in FeAl3 phase and then dissolution of enriched iron portion which is separated from the surface of the phase by agitation of the hydrogen gas evolution.抄録全体を表示PDF形式でダウンロード (456K) -
多根 正和, 市坪 哲, 平尾 雅彦, 森下 智博, 中嶋 英雄2002 年 66 巻 11 号 p. 1073-1077
発行日: 2002年
公開日: 2008/04/24
ジャーナル フリーWe have studied the anisotropic elastic constants of crept copper with the oblate ellipsoidal pores and lotus-type porous copper with long straight pores aligned unidirectionally. We used the combination of resonant ultrasound spectroscopy and electromagnetic acoustic resonance methods to determine all the independent elastic constants with high accuracy. The elastic anisotropy depends on porosity, pore shape, pore orientation, and matrix’s texture. We have calculated the elastic constants by a micromechanics theory, assuming that the pores are ellipsoidal inclusions of zero elasticity. We have obtained good agreement between micromechanics calculations and measurements.抄録全体を表示PDF形式でダウンロード (792K) -
野崎 隆行, 阿部 慎也, 手束 展規, 猪俣 浩一郎, 杉本 諭2002 年 66 巻 11 号 p. 1078-1082
発行日: 2002年
公開日: 2008/04/24
ジャーナル フリーGMR spin-valve type multilayers using a synthetic antiferromagnets (SyAF) free layers consisting of Co90Fe10(t1)/Ru(d)/Co90Fe10(t2) were deposited on a SiO2/Si substrate by using an ultrahigh vacuum magnetron sputtering system and a metal mask. Giant magnetoresistance curves of these multilyers exhibited two types of curves (normal and inverse like type), depending on the magnitude relation of t1 and t2. The magnetization switching field of SyAF free layers was independent of the Ru thickness(d), suggesting that the switching field is independent of the magnitude of the antiferromagnetic interlayer exchange coupling, and was proportional to (t1+t2)⁄Δt, which is in good agreement with the coherent rotation model with perfect antiparallel alignment during magnetization reversal of the SyAF.抄録全体を表示PDF形式でダウンロード (330K) -
井頭 賢一郎, 水田 明能, 西尾 光司2002 年 66 巻 11 号 p. 1083-1090
発行日: 2002年
公開日: 2008/04/24
ジャーナル フリーSi-M(Ti, Zr)-C-O fiber/SiC composites with a thin carbon layer between the fibers and matrix provide good strength and fracture properties. These properties deteriorate in a high-temperature oxidizing atmosphere due to the oxidation of the carbon layer. Such deterioration could be prevented by stopping oxygen penetrating from the outside through pores and cracks in the matrix.
We fabricated Si-M-C-O fiber/SiC composites containing traces of glass which was expected to seal cracks as it softened under high temperatures. We evaluated the oxidation characteristics and creep properties of this glass-containing composite in comparison with a composite having no glass added.
The addition of SiO2-Al2O3-BaO effectively sealed cracks at high temperatures thereby inhibiting oxidation of the carbon layer and silicate formation near the fiber surface. We also confirmed that the addition of SiO2-Al2O3-BaO reduced creep strain rate and significantly increased creep lifetime.抄録全体を表示PDF形式でダウンロード (1175K) -
田上 耕司, 渡邉 和幸2002 年 66 巻 11 号 p. 1091-1097
発行日: 2002年
公開日: 2008/04/24
ジャーナル フリーThe effect of the presence of potassium bubbles on the time law and the mechanism for abnormal grain growth is investigated using powder metallurgy tungsten fine wires. The equiaxed grain growth is almost kept in non-doped wire, following the time law for normal grain growth. On the other hand, the longitudinally elongated grains develop in doped wire because of the grain boundary migration inhibited by Zener pinning due to many arrays of bubbles along the wire axis, showing the strong deviation from the time law for normal grain growth. Thermal grooves are formed along the grain boundaries, which appear on the surfaces of doped and non-doped wires annealed in a vacuum. It is proved that the grain growth of both wires is mainly rate-controlled by surface diffusion because of the grain boundary migration accompanied with the thermal grooves.抄録全体を表示PDF形式でダウンロード (732K) -
赤堀 俊和, 新家 光雄, 松田 幸一, 鈴木 昭弘2002 年 66 巻 11 号 p. 1098-1106
発行日: 2002年
公開日: 2008/04/24
ジャーナル フリーAs-HIP’ed cast α+β type Ti-6Al-7Nb and Ti-6Al-4V for dental applications were conducted with general thermochemical heat processing (THP) and THP combined with a post heat processing (THPH) to refine their microstructure and improved their fatigue strength without decreasing ductility. Then, the fatigue crack initiation and small fatigue crack propagation behaviors of HIP’ed cast Ti-6Al-7Nb and Ti-6Al-4V were mainly investigated in this study.
Fatigue limits of HIP’ed cast Ti-6Al-7Nb and cast Ti-6Al-4V are improved about 40% by THP and THPH as compared with those of as-HIP’ed ones. Fatigue crack initiation and small fatigue crack propagation resistance of HIP’ed cast Ti-6Al-7Nb and Ti-6Al-4V is improved remarkably by THP and THPH as compared with those of as-HIP’ed ones because the effective slip length under the cyclic stress is decreased due to refined microstructure by THP and THPH, and the slips occur uniformly. Fatigue crack initiation and small fatigue crack propagation life of HIP’ed cast Ti-6Al-7Nb and Ti-6Al-4V conducted with THP and THPH are around 80∼90% of the total fatigue life. They increase twice as much as those of as-HIP’ed cast Ti-6Al-7Nb and Ti-6Al-4V (i.e. around 40%).抄録全体を表示PDF形式でダウンロード (1659K) -
野路 典昭, 柏倉 佳介, 赤尾 昇, 相馬 才晃, 原 信義, 杉本 克久2002 年 66 巻 11 号 p. 1107-1115
発行日: 2002年
公開日: 2008/04/24
ジャーナル フリーThe corrosion resistance of W and its alloys for spallation targets was examined in stagnant and flowing water without irradiation. Commercial grade pure W(99.99%), high-purity W(99.999%), super high-purity CVD W(99.9999%), W-2%Ta alloy, W-5%Re alloy, and 93%W-7% Type 304 sintered alloy were used as specimens. Corrosion tests were carried out in boiling water at 373 K under atmosphere, in pressurized water under 1.013 MPa H2 at 373 and 453 K, and in H2-saturated flowing water at 373 K at flow-rates of 5 and 7 m·s−1. After the tests, specimen surfaces were analyzed by Auger electron spectroscopy and X-ray photoelectron spectroscopy. Electrochemical polarization curves of the specimens were measured in 1.0 kmol·m−3 Na2SO4 of pH 6.75 at 298 K. The corrosion mass loss in boiling water decreased in the order of W-Type 304>W-5%Re>99.99%W>99.999%W>W-2%Ta>99.9999%W. The corrosion mass loss in pressurized water was smaller than that in boiling water and decreased with increasing purity. In flowing water, the corrosion mass loss sharply increased with increasing flow-rate and increased with increasing purity of specimen.
Surface films after the corrosion tests were composed of WO2, WOY(2<Y<3), WO3, and H2WO4. The anodic and cathodic polarization curves suggested that corrosion in neutral solution proceeds by an active dissolution-precipitation mechanism.抄録全体を表示PDF形式でダウンロード (1165K) -
北原 弘基, 吉川 泰弘, 吉田 冬樹, 中島 英治, 浜島 和雄, 篠崎 泰夫, 阿部 弘2002 年 66 巻 11 号 p. 1116-1121
発行日: 2002年
公開日: 2008/04/24
ジャーナル フリーThe present study was carried out to clarify the relationship between the microstructures and mechanical properties of Mo2NiB2-Zvol%Ni (Z=0,12, 18, 24 and 50). Fracture surface energy, γi, for crack initiation and work of fracture surface energy, γwof, for crack propagation were selected as suitable parameters for evaluating the mechanical properties. γi and γwof were measured by the Chevron notch three-point bend methods. Both γi and γwof increased with the increase in amount of metal phase in cermets, and γwof were about two or three times higher than γi for all specimens. Both γi and γwof did not increase proportionally to the volume fraction of cermets. In order to clarify that microstructure affected crack propagation, crack propagation patterns were classified to four patterns; transgranular fracture in ceramics (c), intergranular fracture in ceramics (c/c), transgranular fracture in metal (m) and intergranular fracture between metal and ceramics (m/c). The intergranular fracture (c/c) ratio to total crack propagation patterns was large in 0, 12, 18 and 24 vol% cermets, and intergranular fracture (m/c) ratio was large in 50 vol% cermet. Increase in the volume fraction of metal was rearranged as the frequency of cracks to touch metal phase; m+0.5(m/c). Linear relationship was obtained between m+0.5(m/c) and fracture surface energies. The result of fracture surface analysis showed that the large increase in γwof compared with γi with the increase in the volume fraction of metal resulted from the difference of the roughness of fracture surfaces. The fracture surfaces were rougher for the specimens with larger amount of metal phase. γwof was estimated to be about equal to γi when correction was carried out based on the roughness value. It was concluded that fracture surface energies γi and γwof increased proportionally to the fraction of the metal phase which was contiguous to crack.抄録全体を表示PDF形式でダウンロード (1180K) -
虎沢 直樹, 荒井 重勇, 高瀬 喜久, 佐々木 勝寛, 坂 公恭2002 年 66 巻 11 号 p. 1122-1130
発行日: 2002年
公開日: 2008/04/24
ジャーナル フリーMicrostructures of joints between Pb-free solders (Sn-Ag-Cu and Sn-Ag-Cu-Bi) and an electroless Ni-8 mass%P were analyzed comprehensively using transmission electron microscopy(TEM). The specimens for TEM observation were prepared using a focused ion beam(FIB) technique. Columnar and spherical Kirkendall voids are formed at interfaces in the solder joints. TEM observation of a fractured joint reveals that these KV’s lead to degradation of the strength of the joints. Electron diffraction and EDX analysis show definite evidence for occurrence of η-(Cu, Ni)6Sn5 at the interface. Evolution of microstructure during thermal cycling in a temperature range between 253 and 453 K was also analyzed.抄録全体を表示PDF形式でダウンロード (2032K) -
矢野 英治, 和田 典也, 西川 直樹, Tetsuichi Motegi2002 年 66 巻 11 号 p. 1131-1134
発行日: 2002年
公開日: 2008/04/24
ジャーナル フリーTo obtain an ingot of AZ91D magnesium alloy containing granular primary crystals of magnesium in the cast structure, we performed semisolid casting using an inclined cooling plate. In this casting process, molten metal is flown onto the inclined cooling plate to induce the primary magnesium crystal nucleation on the cooling plate. The molten metal containing the primary magnesium crystals which is flown onto the inclined cooling plate is cast in a preheated mold, where the crystals grow into grains. Factors which affect the cast structures are pouring temperature, the angle of the incline, and the length of the cooling plate. Under optimal conditions, an ingot of fine grains is obtained. Next, under optimal conditions of mold casting, we performed continuous casting along a horizontal direction, and we obtained a billet with a diameter of about 40 mm and a length of about 600 mm. All of the cast structures obtained were composed of fine grains.抄録全体を表示PDF形式でダウンロード (606K) -
王 栄光, 森弘 尚希, 岡部 卓治, 向井 弘治, 木戸 光夫2002 年 66 巻 11 号 p. 1135-1142
発行日: 2002年
公開日: 2008/04/24
ジャーナル フリーThe surface compositions of wet polished and air oxidized pure chromium, and the micro-wetting behavior of distilled water on these surfaces, were investigated with X-ray photoelectron spectroscopy (XPS) and the AC non-contact mode of an atomic force microscope (AFM).
Both an organic contaminant/water layer and a chromium oxide/hydroxide layer, where the oxide/hydroxide layer was beneath the contaminant/water layer, were detected by XPS analysis on each surface. The oxide/hydroxide layer became thicker, and the ratio of oxide to hydroxide became larger, after air oxidation. In ambient air, the AFM showed a thin liquid layer on each surface, easily moved by the cantilever of the AFM, and which could be condensed or evaporated. The inner part of the liquid might be adsorbed water, and the outer part of it was thought to be organic contaminant since the liquid would not combine with distilled water applied by post-wetting. Micro water droplets deposited by post-wetting always occupied positions with little or none of this liquid, which might explain the observed higher micro- than macro-wettability.抄録全体を表示PDF形式でダウンロード (2372K) -
佐藤 正之, 金児 紘征2002 年 66 巻 11 号 p. 1143-1149
発行日: 2002年
公開日: 2008/04/24
ジャーナル フリーA pump and sensor combination tubular zirconia oxygen pump-gauge with Ag electrodes was constructed for low-temperature use. The lowest working temperature at which the oxygen pressure could be measured was 550 K. A measured amount of oxygen was pumped into the sensor at 673 K. As a result, the pump-gauge had a high response rate when measuring oxygen above 673 K. This tubular pump-gauge was compared to a planar gauge; the former is suitable for precise control of the oxygen pressure and the latter for a wider range of oxygen pressures.抄録全体を表示PDF形式でダウンロード (406K) -
石山 新太郎2002 年 66 巻 11 号 p. 1150-1156
発行日: 2002年
公開日: 2008/04/24
ジャーナル フリーIn order to develop new energy conversion technique, that is, electric power and hydrogen multi generation system by partial oxidation reaction of methane source using thermo nuclear power, sol-gel and spin coating techniques were employed to make nano ordered thin solid electrolyte film of Ce0.8Sm0.2O1.9, which is expected to exhibit high ion conductivity and low loss of self-electric resistivity in the temperature range of 1073-1273 K. The Ce0.8Sm0.2O1.9 solid electrolyte thin film was investigated to obtain its fundamental properties, and the following conclusions were derived;
(1) Nano ordered electrolyte thin film of Ce0.8Sm0.2O1.9 was synthesized by the combination of sol-gel and spin coating techniques on sapphire substrate from Ce(NO3)36H2O and Sm(NO3)36H2O in ethylene glycol solution.
(2) High crystal perfection and high density of Ce0.8Sm0.2O1.9 nano ordered thin electrolyte film was achieved by firing at 1273 K.
(3) The highest ion conductivity of high temperature electrolytes in the order of 1.4 S·cm−1 at 1273 K was achieved by the formation of the Ce0.8Sm0.2O1.9 nano thin electrolyte film. This would be world record of the high temperature electrolytes.抄録全体を表示PDF形式でダウンロード (1012K) -
張 大石, 北田 正弘2002 年 66 巻 11 号 p. 1157-1162
発行日: 2002年
公開日: 2008/04/24
ジャーナル フリーPossibility of classification manufacturing time by colors and chemical compositions of the glaze in the Choson blue and white porcelains has been investigated. The specimens are the 15th and 18th centuries excavated from the kiln sites in the Choson dynasty. The color of blue pigment layers is measured by a spectrophotometer. The metallic elements of blue pigment layers are obtained with an wave length dispersive X-ray spectrometer. The color of glaze in the Choson blue and white porcelains shows the absorband of 500∼650 nm and this is a attributed to Co2+ ions. The peaks of absorption are approximately 520, 592 and 640 nm. In the dominant wavelength (λd)of colors, the 15th century samples tends to situate longer wavelength area than that of 18th century samples. The border is 476∼477 nm excitation purity (Pe) of the 15th century samples is relative higher than that of 18th century samples. In the glass components in glaze, SiO2 and CaO concentration of the 15th century samples are higher than that of the 18th century samples. The concentration of Al2O3 and K2O of the 18th century sample is higher. The amount of main staining CoO, in the 18th century sample is twice as much as the 15th century samples. On the transition elements, the relative concentrations of Fe, Ni, and Cu of the 15th century samples are high, and the 18th century samples shows high relative content of Mn.抄録全体を表示PDF形式でダウンロード (421K)
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