Journal of the Ceramic Society of Japan (日本セラミックス協会学術論文誌)
Online ISSN : 1882-1022
Print ISSN : 0914-5400
ISSN-L : 0914-5400
101 巻, 1177 号
選択された号の論文の25件中1~25を表示しています
  • 安本 恭章, 山川 晃司, 岩瀬 暢男, 篠沢 法子
    1993 年 101 巻 1177 号 p. 969-973
    発行日: 1993/09/01
    公開日: 2010/08/06
    ジャーナル フリー
    High temperature reactions between AlN and metal thin films were studied. Thin films of Ti, Zr, Cr, Ta, and Ni were sputtered on AlN and annealed isothermally at temperatures between 700°C and 950°C. These films have been classified into the following three groups after 830°C-annealing. Thin films of Ti and Zr formed aluminides at the interface and showed a high adhesion strength over 4.4×107Pa. Thin films of Ta and Cr had high adhesion strength over 4.4×107Pa, observed no compound peak by XRD. Poor adhesion strength of 4.4×105Pa was obtained between AlN and Ni and no compound was found at the interface. Films of titanium formed TiAl3 aluminide in the temperature range of 700°C to 950°C. It was assumed that the following three steps occurred, (1) Ti reduced the surface of AlN to metallic Al and N, (2) Al and N diffused into the Ti film, and (3) an aluminide compound formed. The obtained high adhesion strength of Ti and Zr thin films on AlN is considered to have been resulted from the aluminide formation by reaction between AlN and metal thin films. These abilities depend on the electronegativity of metals. The degrees of reaction between AlN and metal thin films were estimated from the relationships of their electronegativity and standard heat of formation of aluminides. It is possible that aluminides are formed on AlN with elements having electronegativities under 1.34eV, such as Zr (1.22eV), Nb (1.23eV), Mg (1.23eV), Hf (1.23eV), Mo (1.30eV), and Ta (1.33eV).
  • 構造と光学非線形性の関係
    山本 秀樹, 神谷 寛一, 松岡 純, 那須 弘行
    1993 年 101 巻 1177 号 p. 974-979
    発行日: 1993/09/01
    公開日: 2010/08/06
    ジャーナル フリー
    The coordination state of Ge ions in PbO-GeO2 glasses was examined using EXAFS. It was found that a part of Ge ions changed from 4-fold to 6-fold coordination state on addition of PbO, which had been expected from the property-composition relations. The fraction of 6-fold coordinated Ge ions, N6, increased with increasing PbO content up to 20mol%, then decreased on further increase in PbO content. However, the maximum N6 was about 13% and twice as small as that in binary alkali germanate glasses. The refractive index of the glasses, n, increased with increasing PbO content, showing a very faint hump around 20mol% PbO, and third-order nonlinear optical susceptibility, χ(3), monotonously increased from 1.0×10-13 esu at PbO=0 to 5.6×10-13 esu at PbO=40mol% with an increase in PbO content. The absence of germanate anomaly in nor χ(3)-composition relation was explained by the smaller effect of change in coordination state of Ge ions in comparison with that by PbO addition.
  • 1993 年 101 巻 1177 号 p. 979
    発行日: 1993年
    公開日: 2010/08/06
    ジャーナル フリー
  • 佐藤 峰夫, 河野 泰久, 神 哲郎
    1993 年 101 巻 1177 号 p. 980-984
    発行日: 1993/09/01
    公開日: 2010/08/06
    ジャーナル フリー
    Layered perovskite, RbCa2NaNb4O13, with four units of perovskite layer was synthesized by solid state reaction. A sodium ion-exchanged compound, NaCa2NaNb4O13⋅1.7H2O, was also synthesized by ion-exchange reaction of a rubidium compound with NaNO3 molten salt. The anhydrous sodium ion-exchanged compound was stable in the temperature range from 350 to 600°C in an ambient atmosphere. The crystal structures of the three materials were determined using the Rietveld method by powder XRD data. The most reliable solutions were obtained for the structural model assuming that the site for a large cation within the perovskite layer, corresponding to the A site for an ideal perovskite, is occupied by the mixed species with the atomic ratio of Ca:Na=2/3:1/3. The structures of these compounds are substantially the same as those of MLaNb2O7 (M=Rb, Na) except for the thickness of the perovskite layer. A fairly high ion conductivity attributed to the interlayer cation was observed at high temperatures for the sodium compound.
  • ち密化の定量的評価
    西村 聡之, 松尾 陽太郎, 神保 勝久, 木村 脩七
    1993 年 101 巻 1177 号 p. 985-990
    発行日: 1993/09/01
    公開日: 2010/08/06
    ジャーナル フリー
    A new quasi-quantitative constitutive equation of Cyclic-CIP, which contains maximum pressure, bias pressure and number of cycles as variables, was derived. Densification of powder was expressed as a function of maximum pressure assuming that densification rate decreases as the maximum pressure increased. Effect of number of cycles on densification was expressed assuming that densification rate decreases as the number of cycles increased. Effect of the bias pressure was derived from the experimental data as a linear function of the ratio of the bias pressure to the maximum pressure. As a result of analysis of experimental data for two kinds of alumina with this equation, their densification behavior was found to be better characterized by the equation.
  • 赤澤 敏之, 松原 英樹, 高橋 順一, 小平 紘平
    1993 年 101 巻 1177 号 p. 991-995
    発行日: 1993/09/01
    公開日: 2010/08/06
    ジャーナル フリー
    Mn2+-substituted cordierite solid solutions (Mg2(1-X) Mn2XAl4Si5O18, X≤0.6) with a hexagonal crystal structure were prepared by solid state reaction. Expansion in the a-axis direction and contraction in the c-axis direction with increasing Mn2+-substitution were caused by flattening deformation of MgO6 octahedra. The lattice parameters for X=0.6 were a=0.939nm and c=0.929nm. The sintering temperature for densification lowered with increasing Mn2+-substitution. Ceramics with 99% relative density were obtained at 1430°C for X=0, at 1330°C for X=0.25 and at 1230°C for X=0.6. The mean linear thermal expansion coefecients were (0.9-1.1)×10-6°C-1 (20-800°C). Infrared radiation emissivities of ceramics increased with increasing relative density at surface temperatures 100-400°C in the wave length range of 2.5-14.5μm. Thus, the Mn2+-substituted cordierite solid solutions with the theoretical density can be used as infrared radiation ceramics with low thermal expansion coeffiecients.
  • 山川 晃, 三宅 雅也, 石崎 幸三
    1993 年 101 巻 1177 号 p. 996-1000
    発行日: 1993/09/01
    公開日: 2010/08/06
    ジャーナル フリー
    Changes of YAP-phase content and some properties by annealing the Si3N4-Al2O3-Y2O3-AlN ceramics have been studied. Annealing was performed at temperatures 1100-1500°C for 1-10h under vacuum. Above 1200°C, the YAP-phase content in Si3N4 ceramics decreases on annealing and the YAG-phase precipitates. The precipitation of YAG-phase increases the high temperature hardness and chemical resistance to a HF+HN3 solution. The YAP-phase seems to be easily etched by the HF+HNO3 solution and softened at high temperatures compared to YAG-phase.
  • 奥山 良一, 野村 栄一
    1993 年 101 巻 1177 号 p. 1001-1005
    発行日: 1993/09/01
    公開日: 2010/08/06
    ジャーナル フリー
    Sintering behavior of YSZ/NiO-YSZ two-layer ceramics for a tubular SOFC fabricated by the Multilayer Slurry Casting (MSC) process was studied. Cracks were observed in the two-layer ceramics after the sintering process, when the NiO content in the fuel electrode exceeded 50wt% for the electrolyte of 8mol% YSZ. Direct observation of the sintering process and SEM observation of fractured samples showed that cracks occurred at about 1200°C during heating, These results could be explained as that cracks were generated by the difference in sintering rates between the electrolyte (YSZ) and fuel electrode (NiO-YSZ).
  • 浴永 直孝
    1993 年 101 巻 1177 号 p. 1006-1011
    発行日: 1993/09/01
    公開日: 2010/08/06
    ジャーナル フリー
    Judgment of macroscopic crack initiation points (MCIP) in artificial graphite electrodes in fracture toughness tests was discussed by crack gage, acoustic emission (AE) and electrical potential (EP) methods. It is concluded that the crack gage method was not suitable for identifying MCIP, because MCIP was located beyond the maximum load point (Pm) in most cases. In the EP method, the initial increase of EP could not be regarded as MCIP, because generation of microcracks under low-level loading raised EP. Although another procedure to determine MCIP by the EP method was tried, it is concluded that the EP method is unsuitable. Usually, an abrupt increase in accumulated AE energy was regarded as MCIP in the AE method. Even though many abrupt increases were observed, the judgment of abrupt increase corresponding to MCIP was possible, by introduction of AE energy, which was a value of multiplied amplitude of AE observed by its duration, and a proper threshold value. As a result, it was concluded that the AE method was useful for the judgment of MCIP in artificial graphite electrodes. These loads of MCIP are about 88% of those of Pm's.
  • 下尾 聰夫, 小林 康裕, 岡村 清人
    1993 年 101 巻 1177 号 p. 1012-1017
    発行日: 1993/09/01
    公開日: 2010/08/06
    ジャーナル フリー
    The kinetics and the mechanism of the reaction between Si3N4 and Mo have been investigated in N2 or Ar stream at temperatures from 1273 to 1573K. Using a Si3N4-Mo powder mixture, the reaction rates were determined with a thermobalance, and the reaction products were examined by X-ray diffraction. The reaction between Si3N4 and Mo began after heating to about 1450K in N2 stream or about 1250K in Ar stream. In Ar stream, MoSi2 was also produced in addition to both Mo3Si and Mo5Si3 which were the reaction products in N2 stream, whereas Mo nitrides were not detected even in N2. At higher temperatures and on prolonged heating, the silicide changed from Mo3Si to MoSi2 via Mo5Si3. The initial rate followed a linear rate law, and the rate constant k1 in N2 was smaller than that in Ar. Furthermore, the activation energies were 600kJ/mol in N2 and 344kJ/mol in Ar. From a detailed analysis of the kinetic data, an interfacial reaction may be considered as the rate-determining step. At a late stage of the reaction, the kinetics apparently followed a parabolic rate law, and the rate constant kp and the activation energy were significantly changed, depending on the kind of Mo silicide formed as the reaction layer. These results suggest that the reaction rate is probably mixed-controlled by both a interfacial reaction and a solid state diffusion through the reaction layer.
  • 李 相基, 辰巳砂 昌弘, 南 努
    1993 年 101 巻 1177 号 p. 1018-1020
    発行日: 1993/09/01
    公開日: 2010/08/06
    ジャーナル フリー
    The viscosity and thermal properties of glasses in the system Na2O-SiO2 were measured near the transformation temperature. The parameters of fragility, ΔCp and Eη/Tg, increased with an increase in Na2O content. Results of these measurements showed a good correlation between ΔCp and Eη/Tg.
  • 高 鐵, 西川 直宏, 原田 尚幸, 高津 學
    1993 年 101 巻 1177 号 p. 1021-1026
    発行日: 1993/09/01
    公開日: 2010/08/06
    ジャーナル フリー
    The critical temperature difference Δθc was determined by the water quenching test for two differently sized ceramic specimens to study the effects of temperature dependence of material properties and heat transfer coefficient on the thermal shock resistance of ceramics. The observed Δθc at each Biot number β were compared with those calculated numerically, considering the temperature dependence of material properties and heat transfer coefficient h in the thermal conduction equation. The Δθc changed with the size of the specimen, but the thermal shock fracture resistance R was constant for the same type ceramics. Therefore, it was suggested that the R was independent of β and useful for the evaluation of thermal shock resistance.
  • パルス発振モードの場合について
    高橋 千織, 千田 哲也, 天田 重庚
    1993 年 101 巻 1177 号 p. 1027-1031
    発行日: 1993/09/01
    公開日: 2010/08/06
    ジャーナル フリー
    Structural change in plasma-sprayed alumina coatings by laser melting was investigated particularly for pulsed mode treatment. Effects of various processing parameters on the structural change were discussed for one-pass treatment. A three-layer structure consisting of melted, heat-affected and as-sprayed zones was observed in the cross sections of the laser-treated coatings. The depths of both the melted and heat-affected zones depended significantly on the pulse parameters. The treatment increased the Vickers microhardness by 1.6-2.0 times, although defects such as cracks, humps and voids developed in the melted zone. The highest hardness was observed for the thin melted layer with narrow cracks and small humps that was obtained under the conditions of low frequency and small pulse width. These conditions lead to a large temperature gradient and rapid cooling in the layer, because the sample is heated by a high power density beam in a very short time and cooled appreciably during the subsequent interval between pulses.
  • 長瀬 克己, 清水 陽一, 三浦 則雄, 山添 昇
    1993 年 101 巻 1177 号 p. 1032-1037
    発行日: 1993/09/01
    公開日: 2010/08/06
    ジャーナル フリー
    Vanadium-titanium oxide thin films were prepared by sol-gel method. Spin-coating solutions containing VO(O-i-C3H7)3 and Ti(O-i-C3H7)4 in isopropanol could be stabilized properly with the addition of acetylacetone and excess acetic acid. Electrochromic properties of the coated films were strongly dependent both on the atomic ratio of titanium and vanadium, i.e., Ti/(V+Ti) (x) in the coating solutions of alkoxides and on the calcination temperatures. In the case of calcination at 400°C, the films having x=0-0.17 gave the two-step electrochromism, that is, blue↔green↔yellow, while the titanium-rich films, especially those having x=0.60-0.67, exhibited new coloration of reddish-brown at a cathodic potential of -0.8V vs. SCE. On the other hand, the electrochromism of the films calcined at 500°C was similar to that of a pure V2O5 film. No crystalline phases but poorly crystalline TiO2 (anatase) were detected in the 400°C-calcined films having x≥0.60 by XRD, indicating that vanadium oxide should be amorphous. The formation of V3+ in the cathodically polarized films was observed by XPS measurement, which seems to cause the reddish-brown coloration.
  • 浜野 健也, 波多野 敦, 岡田 繁
    1993 年 101 巻 1177 号 p. 1038-1043
    発行日: 1993/09/01
    公開日: 2010/08/06
    ジャーナル フリー
    Amakusa low refractory potterystone contains a certain amounts of soda feldspar, so have not been used as raw materials of porcelain body. Effects of grinding on manufacturing porcelain body from the potterystone were examined. With increase in grinding time, vitrification of the bodies and dissolution of quartz grains were promoted, their closed pores became smaller, and their bending strength became larger from at lower temperatures. In this experimental conditions, high bending strength as 1850kgf/cm2 was obtained with body prepared from the pottery stone ground for 103h, and fired at lower temperature as 1100°C. Bending strength of fired bodies increased with the increase in their bulk density and quartz content up to 20-30%, but had not any relations with their mullite content. The strength also increased with increase of d211 of quartz, which means that the compression prestress of glassy phase surrounding the quartz grains have considerable effects on the strength of the porcelain body.
  • 下野 功, 永田 正一, 小西 哉, 浜口 由和
    1993 年 101 巻 1177 号 p. 1044-1050
    発行日: 1993/09/01
    公開日: 2010/08/06
    ジャーナル フリー
    The high-Tc Bi-Pb-Sr-Ca-Cu-O superconductor (2223 phase) has been prepared by a citrate method. The processing parameters to give the largest amount of 2223 phase were found as follows. The precursor gel powders were first heated at 673K for 1h to decompose organic substances. After being pulverized and pelletized, the samples were sintered at 1133K for 5h. By repeating the above procedure exactly and allowing to cool in the furnace at a rate of 0.5K/min, the superconductor, in which the maximum volume fraction of high Tc-2223 phase attained 89%, was successfully obtained. This value is much greater than that in samples obtained by the conventional solid-state reaction method under the same heat treatment conditions. The zero resistance temperature of the superconductor thus obtained was 101K.
  • 黄 啓祥, 中川 善兵衛, 浜野 健也
    1993 年 101 巻 1177 号 p. 1051-1056
    発行日: 1993/09/01
    公開日: 2010/08/06
    ジャーナル フリー
    Microstructure and mechanical strength of Al2O3-TiO2 ceramics fired in vacuum were studied by X-ray powder diffractometry, scanning electron microscopy, and bending test method. Alumina powder compacts containing 0-4wt% TiO2 were sintered at 1500-1700°C in vacuum (10-3-10-4Pa) and then annealed at 1300°C in air. The solid solubility of TiO2 into Al2O3 increased with an increase in temperature in vaccum. Beyond the solid solubility limit, TiO2 or Al2TiO5 existed in alumina matrix and restrained the grain growth of alumina. Vacuum-sintered bodies which had high solubilities of Ti were annealed in air. Excess Ti ion existing in Al2O3 grains diffused to the grain boundary, and then to the surface of the sintered body, and the annealing treatment slightly decreased the bending strength of sintered bodies.
  • 水嶋 康之, 関根 正裕, 堀 誠
    1993 年 101 巻 1177 号 p. 1057-1061
    発行日: 1993/09/01
    公開日: 2010/08/06
    ジャーナル フリー
    Porous alumina fibers were prepared by the sol-gel method, and palladium was supported on the fibers by dipping and mixing methods. In the latter palladium acetate was mixed with a sol before spinning. Better dispersion of palladium particles in the fiber was achieved by the mixing method than by the dipping method. The specific surface area of the fiber-catalyst prepared by the mixing method was one fiftieth smaller than those of the other catalysts. The activity of the fiber-type catalysts for methane combustion was evaluated and compared with that of a commercial granular-type alumina. The fiber-type catalysts showed higher activities than the granular one. Such a high activity of the fiber-type catalyst prepared by the mixing method, despite its small surface area, was attributed to its fibrous form and better dispersion of palladium particles. However, the activity of fiber-type catalysts drastically decreased by firing at 1200°C for 5h.
  • 藤井 知, 杉江 他曽宏, 小舟 正文, 山本 富彦
    1993 年 101 巻 1177 号 p. 1062-1064
    発行日: 1993/09/01
    公開日: 2010/08/06
    ジャーナル フリー
    The growth of PbTiO3 single crystals from PbO-Cu2O flux method and the electrical properties of the grown single crystals were studied. (1) PbTiO3 crystals grown from a PbO-Cu2O (7wt%) were single crystals, and had a maximum dimension of 4.5×4.5×1.7mm3. (2) All crystals contained less than 0.01wt% Cu ion. Therefore, crystals doped with Cu ion may be showed no variation of the lattice constant. (3) Electrical properties of the crystals were affected by Cu ion. The electrical conductivity of crystals was very low (about 10-12S⋅cm-1) at room temperature. At temperature about 300°C, the current-voltage characteristic curve revealed that the crystal doped with Cu ion was characterized by ohmic and non-ohmic conduction. The critical field strength, EH value, decreased remarkably with increasing temperature.
  • 轟 真市, 平尾 一之, 曽我 直弘
    1993 年 101 巻 1177 号 p. 1065-1067
    発行日: 1993/09/01
    公開日: 2010/08/06
    ジャーナル フリー
    The local structure around Eu3+ ions in sodium aluminosilicate glasses was investigated on the basis of phonon sideband associated with the 5D07F0 transition of Eu3+. It was found that the positive charge of Eu3+ was compensated by nonbridging oxygens (NBOs) in Q3 units rather than by the excess negative charge of AlOn/2(n-3)- units. With the aid of a previous work of Mössbauer results, the coordination change around Eu3+ ions induced by an incorporation of Al has been discussed. It was assumed that NBO-Na+ pairs are replaced by bridging oxygens shared with Si and Al.
  • 勝木 宏昭, 一ノ瀬 弘道, 白石 敦則, 高木 弘義, 平田 好洋
    1993 年 101 巻 1177 号 p. 1068-1070
    発行日: 1993/09/01
    公開日: 2010/08/06
    ジャーナル フリー
    Alumina/kaolin laminated composites have been fabricated at 1650°C by firing multilayers of 1mm thick alumina sheets and 50 or 100μm thick kaolin tapes. During firing, the kaolin layers changed to mixed phases of mullite and SiO2-rich glass. The bending strength of these composites dose not depend on the numbers of laminated kaolin tapes, but depends on the thickness. It was camparable with that of monolithic alumina sheets. The fracture behavior of laminated composites varied with the thickness of kaolin tapes. The composites with pillar-like mullite crystals grown perpendicular to the kaolin layers of 50μm showed a linear relation in the load/deflection curve. On the other hand, the composites prepared with 100μm-kaolin tapes contained two types of mullite crystals: pillar-like mullite crystals grown at the interface between alumina sheet and kaolin tape and needle-like mullite crystals formed in the center area of the kaolin tape. These composites with thicker kaolin tapes showed a non-linear relation in the load/deflection curve.
  • 南口 誠, 山本 新, 粉川 泰浩, José BRICEÑO, 石崎 幸三
    1993 年 101 巻 1177 号 p. 1071-1073
    発行日: 1993/09/01
    公開日: 2010/08/06
    ジャーナル フリー
    Characteristics of sintered filters produced from isotropically packed particles are studied by computer simulation and by experiments using CIPed compacts. From the computer simulation results, the minimal filter thickness for an ideal filter is estimated to be 10 times of the particle diameter. The relationship between pore size and open porosity of the ideal filter is obtained, and is in good agreement with experimental results.
  • 松下 純一, 鈴木 利幸, 佐野 省
    1993 年 101 巻 1177 号 p. 1074-1077
    発行日: 1993/09/01
    公開日: 2010/08/06
    ジャーナル フリー
    High temperature strength of pressureless sintered TiB2 with Cr and C additives had been investigated. The bending strength was measured for temperatures between room temperature and 1400°C in air and in argon atmosphere. The bending strength was 385MPa at room temperature and increased from 560MPa at 800°C to 620MPa at 1000°C in air. The high temperature strength in average in argon atmosphere was nearly constant in the temperature range from room temperature up to 1400°C. The fracture surfaces created in the temperature range between room temperature and 1400°C in argon atmosphere showed both transgranular and intergranular fracture modes.
  • 平尾 喜代司, 柘植 明, Manuel E. BRITO, 神崎 修三
    1993 年 101 巻 1177 号 p. 1078-1080
    発行日: 1993/09/01
    公開日: 2010/08/06
    ジャーナル フリー
    A systematic method of growing rod-like β-Si3N4 single crystals from a melt flux has been developed. β-Si3N4 particles with a diameter of 1-2μm, a length of 10-20μm and a low density of defects were obtained by heating a mixture of α-Si3N4, Y2O3 and SiO2. The residual glassy phase was removed by subsequent acid treatments.
  • ゲル化剤としてプロピレンオキシドを用いた新しいゾル・ゲル法
    伊藤 英信, 田畑 健, 纐纈 三佳子, 岡崎 文保, 射水 雄三, 多田 旭男
    1993 年 101 巻 1177 号 p. 1081-1083
    発行日: 1993/09/01
    公開日: 2010/08/06
    ジャーナル フリー
    A new method for preparing SiO2-Al2O3 gels from aqueous solutions of tetraethoxysilane and aluminum chloride was investigated. Addition of propylene oxide to the solutions promoted gelation reaction, yielding translucent gels. It was found that the 4-coordinated Al incorporated in the framework of the gels was formed without heat treatment. Residual chloride ions were removed from the gels by heating. The gels obtained had large surface areas and were presumed to be homogeneous.
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