巻号一覧
60 巻, 4 号
選択された号の論文の13件中1～13を表示しています
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柏原 智, 常光 幸美, 林 安徳1996 年 60 巻 4 号 p. 347-352
発行日: 1996年
公開日: 2008/04/04
ジャーナル フリーThe electrodeposition of Pt/Co multilayer has been investigated under potential control, referring to observation by reflection electron microscopy (REM). The structure of the multilayers obtained was characterized by transmission electron microscopy (TEM). The REM images revealed that three dimensional growth of Co electrodeposited on Pt(111), and the surface roughness was affected by the extent of overpotential. At a very high overpotential, the Co films consisted of fine homogeneous grains, while at a relatively low overpotential, the grains of Co films became inhomogeneouse. The morphologies of the multilayer interfaces also depended on deposition overpotential. The Pt/Co multilayer prepared by electrodeposition dose not have a texture and column boundaries along the growth direction in contrast to the multilayers prepared by PVD. It is evident that the structure of electrodeposited multilayer is quite different from that prepared by PVD. The relation between the structures of electrodeposited multilayers and the deposition overpotential is discussed.抄録全体を表示PDF形式でダウンロード (2124K) -
田上 稔, Krauns Christian, 住田 雅樹, 中村 優, 山田 容士, 梅田 高照, 塩原 融1996 年 60 巻 4 号 p. 353-359
発行日: 1996年
公開日: 2008/04/04
ジャーナル フリーEach solubility of Y, Yb, Dy, Pr and Sm for the Ba-Cu-O melt in air atmosphere was investigated by ICP measurement. The melt compositions were selected BaCu3O4 for Pr and Ba3Cu5O8 for other elements because these compositions were used to fabricate REBa2Cu3O7−δ (RE; rare earth) by the crystal pulling method. The measurements have been made in the temperature range from approximately 1223 K to about 1573 K. According to these results, the liquidus slope of 123 phase/liquid and 211 phase (110 phase in the case of the Pr system)/liquid was determined at each peritectic temperature.
The solubility of Y for the Ba-Cu-O melt in different O2 partial pressures and P(O2)=2, 21.3, 101 kPa was measured. The decomposition temperature of the Y123 phase increased with increasing oxygen partial pressure. However, the effect of oxygen partial pressure for the Y concentration in the liquid at the temperature range of Y123+Liquid was relatively small.
Furthermore, we estimate the enthalpy of dissolution of RE123, RE211 and Pr110 by a simple thermodynamic model with regular solution approximation.抄録全体を表示PDF形式でダウンロード (634K) -
加藤 鋭次, 加藤 一幸, 野村 宏之1996 年 60 巻 4 号 p. 360-366
発行日: 1996年
公開日: 2008/04/04
ジャーナル フリーMassive Fe compounds are formed when the vibration (low frequency) treatment is applied to Al-Si-Fe base casting alloy with small amount of Cr and Be. Forming conditions and composition of massive Fe compounds have been examined in detail. Formation of the massive Fe compounds starts just below the liquidus line; it occurs at the same time of primary crystallization of α-Al when the vibration treatment is applied. The composition of massive Fe compounds is an AlSiFe(Cr, Be) type one, as the same as the Chinese script Fe compounds and includes a little more Cr content. When massive Fe compounds are formed, the excess Si is discharged around the compound. Such a composition characteristics of massive Fe compounds is explained by a combined concentration segregation during solidification.抄録全体を表示PDF形式でダウンロード (1140K) -
宮川 英明, 森川 龍哉, 岡崎 俊宏, 中島 英治, 吉永 日出男1996 年 60 巻 4 号 p. 367-376
発行日: 1996年
公開日: 2008/04/04
ジャーナル フリーThe stress exponent, n, which is the slope in a log σ-log \dotε curve is about 3 in the intermediate stress range (region M) in the steady state deformation characteristics at high temperature in a solid solution hardened alloy. In the higher stress range (region H) and lower stress range (region L), however, the stress exponents are larger than those in region M.
In this paper, the upper transition stress (σU) between regions M and H and the lower transition stress (σL) between regions M and L for f.c.c. Al-Mg and b.c.c. Fe-Mo alloys are calculated using the flow stress predicting method and compared with the experimental results.
It is found that the predicted transition stress σU or σL almost agree with the experimental one. The flow stress prediction method based on the solute atmosphere drag mechanism should be applied on the stress range from σL to σU.抄録全体を表示PDF形式でダウンロード (1012K) -
小川 裕之, 西野 洋一, 浅野 滋1996 年 60 巻 4 号 p. 377-381
発行日: 1996年
公開日: 2008/04/04
ジャーナル フリーMechanical properties of SiC-whisker-reinforced Al2O3 ceramics were investigated with attention to the volume fraction of SiC whiskers. Experimental results show that the fracture stress and the Young’s modulus increased, while the internal friction decreased, monotonously with increasing volume fraction of SiC whiskers.
The date on the amplitude-dependent internal friction were analyzed on the basis of the microplasticity theory and converted into the plastic strain expressed as a function of stress. This enables one to evaluate non-destructively the stress-strain relation in the forerunning process of fracture of the ceramic composite. The microflow stress at the plastic strain of 1×10−10 increased linearly with increasing volume fraction of SiC whiskers up to 30%. Since the amplitude-dependent internal friction can be measured in the range of elastic deformation, the microflow stress is always reproducible and unaffected by an accidental propagation of the localized crack. However, the variation of microflow stress with the volume fraction corresponds to that of the fracture stress obtained by the three-point bending test. Therefore, it becomes possible to study the mechanical property leading to fracture based on the measurement of amplitude-dependent internal friction in whisker-reinforced ceramics.抄録全体を表示PDF形式でダウンロード (672K) -
高村 博, 大野 湶, 沼田 博雄1996 年 60 巻 4 号 p. 382-387
発行日: 1996年
公開日: 2008/04/04
ジャーナル フリーChemical analysis was performed to study the equilibrium of Ti2+ and Ti3+ in the LiCl-KCl eutectic melt. It was confirmed that the Ti2+ ion was formed by the following inverse-disproportionation reaction
(This article is not displayable. Please see full text pdf.)
\ oindentfrom Ti3+ and titanium metal added.
On the other hand, the Ti2+ ion produced by the constant potential electro-reduction from Ti3+ was subjected to the backward reaction of (1) attaining an equilibrium. The solubility of Ti2+ exhibits somewhat low to be 2.0×10−1 (mol%). It was also found that the addition of alkali fluoride in the LiCl-KCl eut. melt retarded the inverse-dispropotionation reaction improving the stability of the Ti3+ ion.抄録全体を表示PDF形式でダウンロード (646K) -
高村 博, 大野 湶, 沼田 博雄1996 年 60 巻 4 号 p. 388-397
発行日: 1996年
公開日: 2008/04/04
ジャーナル フリーElectrodeposition of titanium from the LiCl-KCl eutectic melt containing TiCl3 has been studied by means of an electrochemical polarization method and scanning electron microscope. The cathodic polarization curves for the Ti3+ exhibited the Tafel lines having slopes of one and two electron transfer reactions where the former reaction corresponds to the reduction of Ti3+ to Ti2+ and the latter to that of Ti2+ to Ti.
The silver metallic films were obtained by washing the dense mossy deposits electrodeposited at −1.28 and −1.45 V using a soluble Ti anode. It was also found that the glossy film was attributed to highly crystalline orientation of (002).
The cathodic reduction for Ti3+ from LiCl-KCl eut. containing alkali fluoride exhibited three electron reduction waves from Ti3+ to Ti at less noble potentials than that of the relevant reaction in the LiCl-KCl eut. melt. The electrodeposited film exhibited a plate-like ledged structure.抄録全体を表示PDF形式でダウンロード (1884K) -
原 基, 中川 時子, 山口 邦彦, 浅見 勝彦, 橋本 功二1996 年 60 巻 4 号 p. 398-405
発行日: 1996年
公開日: 2008/04/04
ジャーナル フリーThe peculiar chlorine evolution behavior of the platinum electrode was investigated by the measurement of the photocurrent vs. polarization potential curve and X-ray photoelectron spectroscopy, in comparison with that of the palladium electrode. The signs of photocurrent measured for platinum and palladium under anodic polarization were positive, suggesting that the surface oxide films formed on both metals have n-type conduction. The photo-current measured for platinum exhibited a wavy change with an increase in polarization potential, in analogy with the potential dependence of the rate of chlorine evolution reaction. An X-ray photoelectron spectroscopic study showed that the chemical composition of the surface oxide film formed on platinum changed with increasing polarization potential. Increases in Pt4+ ions, OM oxygen and zero-valent chlorine and a decrease in OH oxygen in the film with the increase in potential were observed. Therefore, the drop in chlorine evolution rate for platinum in the high potential region corresponds to the change in chemical composition of the film formed on platinum, that is, a change from PtO to PtO2. The wavy changes in the chlorine evolution rate and the photocurrent with an increase in potential was explained by a change in potential difference at the Helmholtz layer corresponding to that in the surface state from Pt2+-Cl− to Pt4+-Cl−.抄録全体を表示PDF形式でダウンロード (739K) -
須藤 雄一郎, 竹下 博之, 鈴木 亮輔, 冨井 洋一, 小野 勝敏1996 年 60 巻 4 号 p. 406-411
発行日: 1996年
公開日: 2008/04/04
ジャーナル フリーFor the application of SIMS (Secondary Ion Mass Spectrometry) to quantitative analysis for the dilute element in metallic alloys, it is indispensable to eliminate the disturbance which is counted with the secondary ions of the dilute element. Ti2+ ions from the Ti matrix overlap the Mo+ ions from the Ti-dilute Mo alloys However, a conventional SIMS could not be applied to separate Ti2+ ions either by its high resolution mass analysis or by the separation based on the energy profiles. Since the secondary ion intensities of Mo+ and Ti2+ are proportional to their isotopic abundances, the secondary ion intensity of Mo+ can be calculated and separated from the measured intensity. Using the ion intensity of 92Mo+ or 100Mo+ after the disturbance elimination and the normalization, a good linear relationship for the quantitative Mo analysis was obtained in the range of 766 mass ppm to 2.31 mass%Mo. The lower quantitative limit is evaluated to be 80 mass ppm due to the improved preciseness.抄録全体を表示PDF形式でダウンロード (712K) -
永山 勝久, 小林 史郎, 山村 二広, 鈴木 俊夫, 栗林 一彦, 深山 春生1996 年 60 巻 4 号 p. 412-419
発行日: 1996年
公開日: 2008/04/04
ジャーナル フリーWe investigated the possibility of metastable phase formation and functional properties of the magnetic system accompanied with floating melt solidification of materials by using the electromagnetic levitation apparatus. Expected for a microgravity experimental apparatus used in an airplane, and then we established and studied the basic technique of this apparatus in detail. As a result, the crystallization of ferromagnetic metastable phase with the high coercive force unreported until now was obtained in the containeless floating melt solidification sample of the Nd-Fe binary alloy. In addition, we investigated the non-equilibrium solidification process in a new high speed cooling curve measurment system and a new result was obtained.抄録全体を表示PDF形式でダウンロード (1181K) -
島岡 三義, 大中 逸雄1996 年 60 巻 4 号 p. 420-426
発行日: 1996年
公開日: 2008/04/04
ジャーナル フリーIt is difficult to produce the continuous fiber of a low surface tension alloy with a round cross-section by using the In-Rotating-Liquid-Spinning process. The relation between the cross-sectional shape of the fiber and the spinning conditions has been examined by using a Sn-37 mass%Pb alloy. The mean mass flow rate of molten metal jet was almost independent of the superheat of the melt. However, the direction of the jet stream became unstable with increasing superheat of the melt and the fluctuation of the jet diameter at the outlet of the nozzle also increased. The roundness of the cross-section of the obtained fiber increased with decreasing ejection pressure, circumferencial velocity of rotating liquid layer, nozzle diameter, jet incidence angle and density of coolant and with increasing superheat of the melt. The fiber with high roundness could be produced, when the inner pressure of jet was higher than the dynamic pressure of coolant acting on the jet at the incidence point of jet into the liquid layer. The computer simulation of the cooling process of jet has been performed in the temperature range from the ejection to the liquidus temperature of the alloy. The average cooling rates were evaluated to be 0.5∼2.4×105 Ks−1, in the water layer, 1.4∼3.0×104 Ks−1 in the methanol layer and 4.7∼6.5×103 Ks−1 in the salad oil layer, respectively. By using methanol and salad oil as a coolant, a more round fiber could be produced, even if the superheat of the melt was low. The double layers, such as the methanol-water layer and the salad oil-water layer, and the triple layer such as salad oil-methanol-water layers were also effective in producing the fiber with round cross-section.抄録全体を表示PDF形式でダウンロード (717K) -
井藤 幹夫, 真島 一彦, 勝山 茂, 永井 宏1996 年 60 巻 4 号 p. 427-432
発行日: 1996年
公開日: 2008/04/04
ジャーナル フリーThe preparation of Sm2Fe17Nx permanent magnet powders has been tried by mechanical grinding (MG) for a short time without crystallization heat treatment which was usually needed to obtain a Th2Zn17 structure in the conventional method by MG or MA. MG was carried out in three kinds of atmospheres; i.e., Ar, N2 and NH3 gas. Non-treated and hydrogenated Sm2.5Fe17 alloy powders were used as the starting materials. The α-Fe precipitation was detected in the powder after MG for over 14.4 ks. The grain size of powder obtained by MG for 10.8 ks was around 10 nm which was much finer than the single magnetic domain size of about 300 nm. The existence of hydrogen promoted not only the nitriding of powders but the oxidation. The hydrogenated powder after MG in NH3 and nitriding had a high oxygen content of about 13000 ppm. This oxidation prevented the absorption of nitrogen during the nitriding process. The non-treated powders after MG in NH3, however, were nitrided efficiently up to 38000 ppm at a low temperature of 623 K, and the oxygen content was about 7000 ppm. The maximum coercivity of 0.93 MA·m−1 (11.7 kOe) was obtained with the non-treated powder after MG in NH3 and nitriding at 623 K for 10.8 ks in N2.抄録全体を表示PDF形式でダウンロード (811K) -
細見 政功, 前田 尚志1996 年 60 巻 4 号 p. 433-439
発行日: 1996年
公開日: 2008/04/04
ジャーナル フリーThe formation behaviour of lamellar structure in α2+γ type titanium aluminides has been investigated on the specimens hot worked in the single α phase followed by a number of cooling processes. The lamellar structure can be formed with cooling rates slower than the critical cooling rate (CCR), and the CCR varies with Al content, with the following emprical equation:
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\ oindentThe faster the cooling rate, the lower the γ phase precipitation temperature, resulting in the finer γ plates, because of the increase of nucleation of the γ phase. In the isothermal process, the nucleation and growth of γ phase was faster at the temperature in the α2+γ phase region than in the α+γ phase region. It was suggested that the ordering of α phase could accerate the kinetics of γ phase precipitation.抄録全体を表示PDF形式でダウンロード (2134K)
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