巻号一覧
47 巻, 9 号
選択された号の論文の20件中1～20を表示しています
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北川 賀津一, 山名 一男, 中村 静夫, 北川 和夫, 山本 孝2000 年 47 巻 9 号 p. 935-940
発行日: 2000/09/15
公開日: 2009/05/22
ジャーナル フリーIn piezoelectric ceramics for the high-power application, small elasticity losses and excellent durability are required. When the acceptor is added in the Pb(Zr, Ti)O3, which is abbreviated to be PZT, the mechanical quality factor (Qm) increases, while the material hardens and the elasticity loss is improved. In this paper, we study piezoelectric property, crystal structure and microstructure for PZT. The maximum value of Qm was obtained in the sample with 0.005 mol% Fe2O3. In case of MnO2 addition, the electromechanical coupling factor (k31) value gradually lowered over 0.01 mol% addition. The Qm value drastically decreased over 0.02mol% addition.
The crystal structure of the PZT was tetragonal phase. By MnO2 addition of 0.005-0.01mol%, the lattice constants a and c together shorted a little. Over 0.02mol% addition, the lattice constant c decreased and the lattice constant a increased, and the crystal structure was approached to cubic phase. In case of MnO2 addition, the c/a ratios were almost constant within the 0.005-0.02 mol%. The grain growth became remarkable of sintered compact with the increase of the doped quantities.抄録全体を表示PDF形式でダウンロード (2250K) -
近藤 勝義, 瀧川 貴稔, 渡辺 龍三2000 年 47 巻 9 号 p. 941-945
発行日: 2000/09/15
公開日: 2009/12/04
ジャーナル フリーThe effect of the lubricant on the compaction behavior in warm compaction of iron powder was examined by using Cooper-Eaton equation. Particle rearrangement depends on the lubrication effect between powder particles and is more dominant on its compaction behavior than the plastic deformation of powder particles until 423K. The total fractional volume compaction calculated by this method corresponds to the measured density of the green compact. Therefore, this analytical method is available to evaluate the warm compaction behavior quantitatively.抄録全体を表示PDF形式でダウンロード (434K) -
Kazuhiko Tanaka, Koji Hayashi2000 年 47 巻 9 号 p. 946-950
発行日: 2000/09/15
公開日: 2009/05/22
ジャーナル フリーThe authors had already succeeded in synthesizing the powders of new tungsten and molybdenum mono-carbonitrides, i.e., W(C, N) and Mo(C, N), by the following two processes: (1) high-pressure process: heating of W+C and Mo+C mixed powder in N2 gas of 10-150 MPa at 1523-1773 K, and (2) normal-pressure process: heating of W and Mo powder in CH4+NH3 mixed gas of 0.1 MPa at 1373-1573 K. In this study, the synthesis of (W0.3Mo0.7) (C, N) was attempted by the latter normal-pressure process, i.e., by heating W-70at%Mo alloy+C mixed powder in NH3 gas (method I) and by heating the alloy powder in CH4+NH3 mixed gas (method II). It was found that (W0.3Mo0.7) (C, N) with nitrogen contents of 23-21 at% could be synthesized by method II at 1373-1573 K. The maximum nitrogen content was fairly larger than 5 at% of W(C, N) and 17 at% of Mo(C, N) synthesized by method II, and also larger than 16-21 at% of (W0.3Mo0.7)(C, N) synthesized by the high-pressure process at 10-150 MPa.抄録全体を表示PDF形式でダウンロード (4045K) -
Jun-Gyu Kim, Won-Seung Cho, Koji Hayashi2000 年 47 巻 9 号 p. 951-957
発行日: 2000/09/15
公開日: 2009/05/22
ジャーナル フリーThe effects of test piece length, composition (additives of Sb and Sr) and kinds of measuring atmosphere (air, O2, N2 and H2) on positive temperature coefficient of resistivity (PTCR) characteristic were investigated for our newly developed (Ba, SrXTi, Sb)O3 vacuum-sintered compacts added with partially oxidized Ti powder. It was concluded that the development of PTCR characteristic in the compact is surely caused by the bulk property of the compact itself and that both Sb and Sr play no roles in the development of PTCR characteristic. It was suggested that the development of PTCR characteristic in the compact is caused by the adsorption of oxygen at (Ba, Sr)(Ti, Sb)O3 ceramic grain boundaries and the transformation from ferroelectric-tetragonal phase to paraelectric-cubic phase, in a similar way to that in usual BaTiO3-based air-sintered compact without partially oxidized Ti powder.抄録全体を表示PDF形式でダウンロード (613K) -
唐 新峰, 陳 立東, 織部 信次, 潘 偉, 後藤 孝, 平井 敏雄2000 年 47 巻 9 号 p. 958-962
発行日: 2000/09/15
公開日: 2009/05/22
ジャーナル フリーFilled skutterudite compounds, YyFexCo4-xSb12(x=0-1.0, y=0-0.4), were synthesized by solid state reaction and melting methods using Co, Fe, Sb, YCl3·nH2O Powders and Y ingot as source materials. The Rietveld analysis suggests that Y3+ ions were filled in the Sb-icosahedron voids of skutterudite structure. The rattling effect of Y3+ ions filling in the voids were stronger than that of Ce3+ or La3+ ions. The lattice thermal conductivity decreased with increasing Y filling fraction, and reached the mimimum values at y=0.3. With increasing Y filling fraction, the electrical conductivity decreased and the Seebeck coefficient increased. The maximum ZT value of 0.7 at 750K was obtained for Y0.08Fe0.8Co3.2Sb12.抄録全体を表示PDF形式でダウンロード (327K) -
仙名 保2000 年 47 巻 9 号 p. 964
発行日: 2000/09/15
公開日: 2009/05/22
ジャーナル フリーPDF形式でダウンロード (101K) -
石垣 隆正, 目 義雄, 伊ヶ崎 文和, 北澤 宏一2000 年 47 巻 9 号 p. 965-974
発行日: 2000/09/15
公開日: 2009/05/22
ジャーナル フリーConcertedAmplifzcation is defined as "Induced non-linear phenomena in the proceeding reaction fields by external energy". Research on Advanced Materials Processing on the Basis of Concerted Amplification started in 1998 by Special Coordination Funds of the Science and Technology Agency of the Japanese Government. Seventeen organizations take part in the research program with various techniques of external energy, such as magnetic field, electric field, plasma, ultrasonic wave, and mechanical energy. Some distinguished results obtained through the collaborative works are described.抄録全体を表示PDF形式でダウンロード (5995K) -
北條 純一, 上原 雅人, 榎本 尚也2000 年 47 巻 9 号 p. 975-980
発行日: 2000/09/15
公開日: 2009/05/22
ジャーナル フリーCeramic nanocomposites can be fabricated from composite powders. In particular, the nanostructure is easily formed from the finely-mixed amorphous state. The phase separation and crystallization of the composite powders during heating were investigated in Si3N4-BN and Si3N4-TiN systems. The powders were prepared by a vapor phase reaction method and heat-treated at 1600°C in N2 with and without Y2O3-Al2O3 sintering aid. The crystallization and particle growth of Si3N4 were retarded by BN inclusion. Si3N4-BN composite powder was amorphous even at 1600°C without sintering aid, whereas β-Si3N4 crystallized at 1600°C with sintering aid. IR analysis indicated that Si3N4 and BN separated with a rise of temperature and the crystallization was accelerated by sintering aid. In Si3N4-TiN system, TiN accelerated the crystallization of β-Si3N4. It was found that BN was expelled from Si3N4 particles with and without sintering aid, whereas TiN was surrounded by Si3N4 particles with sintering aid. Si3N4-BN and Si3N4-TiN nanocomposites were fabricated by hot pressing at 1800°C. The excellent thermal-shock resistance was observed in Si3N4-BN system and the high fracture toughness in Si3N4-TiN system in which the growth of Si3N4 rod-like grains was enhanced by fine TiN inclusions.抄録全体を表示PDF形式でダウンロード (5152K) -
石垣 隆正, 片岡 英二, Yali Li, 羽田 肇2000 年 47 巻 9 号 p. 981-986
発行日: 2000/09/15
公開日: 2009/05/22
ジャーナル フリーTiC-TiO2 composite powders were prepared by in-flight oxidation of titanium carbide powder in RF induction thermal plasmas. Original titanium carbide powder of 20-38μm in particle size was axially injected into the center of argon-oxygen plasma. The powders were partially spheroidized and evaporated through the plasma treatment. X-ray diffraction of plasma-treated powders showed the formation of titanium dioxides, both rutile and anatase phases. The phase content of the plasma-prepared powders strongly depended on the plasma conditions, such as the plasma generating pressure and the oxygen flow rate in plasma generating gas. Especially, the increase of oxygen flow rate in plasma gas gave rise to the increase of heat transfer from plasma to powder particles, exothermic heat of oxidation reaction and cooling rate of plasma, giving the increase of spheroidization ratio, formation ratio of titanium dioxides, and content of anatase phases.抄録全体を表示PDF形式でダウンロード (2629K) -
栗原 雅人, 丸山 哲, 田中 秀樹, 守吉 祐介, 石垣 隆正2000 年 47 巻 9 号 p. 987-992
発行日: 2000/09/15
公開日: 2009/05/22
ジャーナル フリーMesocarbon microbeads (MCMB) powders were treated in Ar-H2, Ar-N2, Ar-H2-CO2 and Ar-N2-CO2 induction thermal plasmas under reduced pressure of 53 kPa. The plasma treated powders were characterized by X-ray diffractometry (XRD), scanning electron microscopy (SEM) and Raman spectroscopy. The plasma treatment did not give rise to the graphitization in the bulk, but gave the modification subjected to the surface morphology, structure and chemical composition. The surface of the Ar-N2 plasma-treated particles was covered by the fine condensate, while the surface morphology of Ar-N2-CO2 plasma-treated particles became rough and had no condensate. Electrochemical measurements as an anode of lithium rechargable battery were performed in 1M LiClO4/(ethylene carbonate [EC] + diethyl carbonate [DEC]). Discharge capacity of the plasma-treated MCMB powders is larger than that of original MCMB powders. Also, first discharge/charge efficiency of the MCMB powders treated in the atmospheres containing CO2 is higher than that of original powders. These results suggest that the modification of the surface structure, morphology and chemical composition by the plasma treatment can be improved the properties as an anode material for the lithium secondary battery.抄録全体を表示PDF形式でダウンロード (1598K) -
奥山 秀男, 本間 一廣, 大野 悟2000 年 47 巻 9 号 p. 993-998
発行日: 2000/09/15
公開日: 2009/05/22
ジャーナル フリーSimultaneous process of the production of spherical Ni powder and its surface-modification with Fe ultra-fine particles was demonstrated using an Ar RF plasma. In a reactor chamber, Fe raw powder introduced into the plasma flame was vaporized then condensed into Fe ultra-fine particles, while Ni raw powder introduced below the flame was melted then formed into spherical powder. Reaction characteristics of the Ni and Fe powders were investigated by varying the Ni/Fe supply ratio and the position of a counter-nozzle, which provided Ni powder, from the tip of the plasma flame. SEM observation and EDX analysis showed the spherical Ni powder is surface-modified with Fe ultra-fine particles.抄録全体を表示PDF形式でダウンロード (5952K) -
岩崎 将任, 滝沢 博胤, 上田 恭太, 遠藤 忠2000 年 47 巻 9 号 p. 999-1003
発行日: 2000/09/15
公開日: 2009/05/22
ジャーナル フリーThe effect of 28 GHz microwave irradiation was investigated on the optical properties of stannic oxide (SnO2). During microwave irradiation, the temperature of SnO2 rose rapidly and reached 1400°C within a few minutes. After microwave irradiation, commercial whitish green SnO2 turned to pale claret one. X-ray diffraction analysis did not reveal any phase changes or differences in lattice parameters as compared with those of SnO2 conventionally heated (1400°C, 43.2ks). Diffuse reflectance spectroscopy detected the absorption peak of claret SnO2 obtained by microwave irradiation in the range of 450-650nm. The same absorption was detected in SnO2 heated conventionally (1400°C, Os), but after annealing the claret sample turned to white one. On the other hand, microwave-irradiated sample maintained the color after long period annealing. From the X-ray photoelectron spectrometry, we found that the binding energy of Sn in claret SnO2 obtained by microwave irradiation shifted to a lower level than that of white SnO2.抄録全体を表示PDF形式でダウンロード (421K) -
木村 博, 佐治 他三郎2000 年 47 巻 9 号 p. 1004-1009
発行日: 2000/09/15
公開日: 2010/07/12
ジャーナル フリーThe methodology of multi-variables control in millimeter wave sintering is set up, in order to provide a route to the design and development on advanced materials of next generation such as bulk nanocrystalline ceramics. The 28 GHz microwave sintering system has an intelligent peripheral equipment with a specially designed displacement sensor necessary for the real-time measurement and the closed loop control of a linear shrinkage. The CIP'ed compact of amorphous ZrO2-20mol%A12O3 powder, as synthesized via mechanical alloying, can be sintered to a full density without any macroscopic crack by employing millimeter wave heating followed by holding at a relatively low temperature of 1523 K. The rapid densification of the nanocrystalline ZrO2-20mol%Al2O3 compact in heating under a high frequency electric field is fairly well expressed by an Arrhenius relation ofε=Aexp (-H/kT) with an apparent activation energy (H) of 198 kJmol-1. Furthremore, the apparent activation energy tends to increase with increasing relative density in the case of a constant densification rate control sintering.抄録全体を表示PDF形式でダウンロード (2143K) -
鈴木 達, 大塚 秀幸, 目 義雄, 平賀 啓二郎, 北澤 宏一2000 年 47 巻 9 号 p. 1010-1014
発行日: 2000/09/15
公開日: 2009/05/22
ジャーナル フリーAligned alumina was synthesized by using colloidal processing and a high magnetic field. Fine alumina powder dispersed in suspension was oriented under a high magnetic field (10T) owing to crystal magnetic anisotropy. When the green compact prepared by slip casting in a high magnetic field was annealed at low temperatures, grain growth occurred with grain alignment. During annealing at high temperatures platelet grains grew, thus the degree of alignment increased. The c-plane of alumina was perpendicular to an applied magnetic field.抄録全体を表示PDF形式でダウンロード (3312K) -
目 義雄, 打越 哲郎, Benjamin Hatton2000 年 47 巻 9 号 p. 1015-1020
発行日: 2000/09/15
公開日: 2009/05/22
ジャーナル フリーElectrophoretic deposition (EPD) usually requires the use of non-aqueous colloidal suspensions, to avoid the problems of void formation by the electrolysis of H2O. Recently, we found that no voids were formed in the deposit prepared by aqueous suspension using a palladium. The preparation and characteristics of suspensions are important for factors such as deposition rate, zeta potential, and particle size distribution. Experimental results showing the effect of washing on the stability and EPD for aqueous and non-aqueous suspensions of as-received zirconia (3 mol% Y2O3 doped tetragonal ZrO2: Tosoh TZ3Y) and four kinds of alumina fine particles are presented here. The zeta potential and, hence, suspension stability, of TZ3Y-ethanol system were increased by washing. As a result, EPD rate increased dramatically from the as-received condition. There were no significant beneficial effects of washing on the aqueous system, indicating a much greater sensitivity to ionic contaminants in an ethanol suspension especially for the TZ3Y. Green densities prepared by EPD using aqueous suspensions were higher than those by EPD using ethanol suspensions and similar to those by slip casting using aqueous suspensions.抄録全体を表示PDF形式でダウンロード (2007K) -
打越 哲郎, Yoko Fukada, 鈴木 達, Patrick S. Nicholson2000 年 47 巻 9 号 p. 1021-1025
発行日: 2000/09/15
公開日: 2009/12/04
ジャーナル フリーSurface coating of Si3N4 powder with an alumina precursor was achieved by a sol-gel method using aluminum isopropoxide. Electrophoretic data showed the surface-coated Si3N4 powder behaved like alumina. Consolidation of the surface-coated powder was attempted by an electrophoretic deposition (EPD) technique. EPD rate was improved for the surface-coated powder. Sintering characteristics and fracture toughness were investigated for EPDed compacts. It was demonstrated that the surface coating of Si3N4 powder with alumina precursor had the advantage of not only the improvement of suspension stability, but also the addition of sintering aid.抄録全体を表示PDF形式でダウンロード (1720K) -
八代 圭司, 工藤 正和, 松本 弘樹, 開米 篤志, 二唐 裕, 川田 達也, 水崎 純一郎, 河村 憲一2000 年 47 巻 9 号 p. 1026-1031
発行日: 2000/09/15
公開日: 2009/05/22
ジャーナル フリーThe electrochemical property of the galvanic cell, P(O2)I+P(CO), Au/YSZ/Pt, P(O2)II, has been studied for the applications of CO sensor. In order to elucidate the CO-sensing mechanism on Au/YSZ interface, steady state polarization measurements were carried out at 873-1073 K in O2-Ar, CO-CO2, CO-O2-Ar systems. The quantitative analysis of the I-V characteristics revealed the kinetics of the electrode reaction with O2, CO and CO2. The current density at Au/YSZ interface in CO-O2-Ar system can be formulated. As a result, it was confirmed that mixed potential was generated by a small amount of CO in oxygen-containing streams.抄録全体を表示PDF形式でダウンロード (420K) -
安藤 知栄, 井口 喜章, 岸 弘志, 柳川 塁, 仙名 保2000 年 47 巻 9 号 p. 1032-1035
発行日: 2000/09/15
公開日: 2009/12/04
ジャーナル フリーEffects of agitation milling of either TiO2 or a mixture of TiO2 and BaCO3 on the solide-state synthesis and properties of BaTiO3 are studied. Milling TiO2 produces the surface defects. For a mixture of TiO2 and BaCO3, milling brings not only high compositional homogeneity but also forms BaTiO3 precursor. The rate of formation of BaTiO3 is examined by high temperature X-ray diffraction analysis. Synthesis of BaTiO3 is accelerated by compositional homogeneity and BaTiO3 precursor formation from the stating mixture by agitation milling. BaTiO3 powders that have been mechanically treated starting mixture, and calcined at 1100°C comprise homogeneous spherical particles with narrow particle size distribution.抄録全体を表示PDF形式でダウンロード (3110K) -
大石 秀伸, 仙名 保, 磯部 徹彦, 三留 秀人2000 年 47 巻 9 号 p. 1036-1038
発行日: 2000/09/15
公開日: 2009/05/22
ジャーナル フリーFerroelectric perovskite lead titanate is synthesized from titania sol and lead oxide sol via various precursors. Ultrasonication and milling were performed either separately or simultaneously during precursor preparation. By these treatments, agglomerates were significantly disintegrated, with concomitant mechanochemical incipient reaction toward PbTiO3. Dispersion state of the product precursor is significantly improved when mechanochemical effects are combined with ultrasonication.抄録全体を表示PDF形式でダウンロード (210K) -
仙名 保2000 年 47 巻 9 号 p. 1039-1045
発行日: 2000/09/15
公開日: 2010/07/12
ジャーナル フリーTheoretical background of bridging bond formation of dissimilar metal atoms mediated by an oxygen atom is given for the system Ca(OH)2-SiO2. Physicochemical significance of low coordination state is emphasized in conjunction with higher reaction probability. A solid state addition reaction at room temperature is shown to be well possible when mechanical stress is applied to promote materials transfer via a mechanical diffusion. Application of such a soft-mechanochemical process is given for complex perovskite oxides. Associated ligand field distortion is also used for solid state synthesis of Fe (II) octahedral comlexes, e.g., Fe (II) (phen)2Cl2, where phen denotes 1, 10-phenanthroline.抄録全体を表示PDF形式でダウンロード (598K)
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