著者

平田 好洋 松下 晋一 中釜 晋 石原 義巳 堀 三郎

出版者

公益社団法人日本セラミックス協会

雑誌

日本セラミックス協会学術論文誌 : Nippon Seramikkusu Kyokai gakujutsu ronbunshi (ISSN:18821022)

巻号頁・発行日

vol.97, no.1129, pp.881-887, 1989-09-01

被引用文献数

5 14

---

Dispersion, rheology and consolidation of the colloidal suspension in the alumna powder-silicon nitride whisker system were studied to control the microstructure and density of the green compact. Al_2O_3 particles with au average diameter of 0.15 μm and Si_3N_4 whiskers with an average size of 0.4 μmX3.7μm were electrostatically dispersed in water in the pH range 3 to 10 and consolidated by filtration. Well- dispersed stable suspensions were obtained at low pH. Decreasing the viscosity and at the same time increasing the solid content of the suspension is the hey step in making the green compact with high density and a narrow pore size distribution. Application of isostatic pressing to compacts consolidated by filtration increased green density and shifted the pore size distribution to smaller size. These green compacts by colloidal processing were densities to relative densities of 98.4-99.4% by hot-pressing at 1500℃ at a pressure of 39 MPa in N_2 atmosphere.

著者

内藤 牧男 堀田 禎 早川 修 篠原 伸広 植松 敬三

出版者

公益社団法人日本セラミックス協会

雑誌

日本セラミックス協会学術論文誌 : Nippon Seramikkusu Kyokai gakujutsu ronbunshi (ISSN:18821022)

巻号頁・発行日

vol.106, no.1236, pp.811-814, 1998-08-01

被引用文献数

9 13

---

The effect of ball milling conditions on pulverization of the very small amount of large particles in silicon nitride powder was examined. In this paper, the wet sieve analysis and X-ray sedimentation method were used to measure the content of large particles in the ground powder which influence important properties of sintered ceramics such as fracture strength. As a result, it was made clear-that the wet sieve analysis would be a reliable method to measure the content of just a few large particles in the ground powder. By applying this analysis to the ball-mill grinding of silicon nitride powder, it was found that the processing conditions required to grind the large particles were different from those to obtain high specific surface area as well as small average size of particles. This is because the impact force exerted onto the particles by the media balls is more effective on grinding large particles.

著者

横田 耕三 村井 俊介 品川 一成

出版者

公益社団法人日本セラミックス協会

雑誌

日本セラミックス協会学術論文誌 : Nippon Seramikkusu Kyokai gakujutsu ronbunshi (ISSN:18821022)

巻号頁・発行日

vol.114, no.1336, pp.1138-1143, 2006-12-01

被引用文献数

2 4

---

The influence of particle size distributions of submicron high-purity α-alumina powders on forming and sintering behavior in an agglomerate-free condition were investigated. Nine kinds of alumina powders with the same median diameter (d_<PM50>=0.53μm) and different geometrical standard deviations (σ=1.2-2.0) in lognormal particle size distributions were prepared by blending spherical-like commercial α-alumina powders, and were also adjusted to near ideal distributions so that σ of a mass distribution was comparable with one of the number distribution. In order to prevent the agglomerate and contamination of the impurities, forming was performed by means of the colloid process, i.e., the slip casting method using the porous alumina molds. Relative densities of green compacts and bodies sintered at up to 1300℃ increased with increasing σ, but densities of bodies sintered at 1500℃ or more increased with decreasing σ. The width of the grain size distributions of those bodies increased with increasing σ. The abnormal grains over 30μm of the grain size generated at more than 1.7 of σ for alumina bodies sintered at 1700℃ and those grains contained many pores. The powder with a narrow distribution in size is better to fabricate a translucent material.

著者

Wang Yao-Wen Zhao Peng-Sheng Zhang Yong-Qing

出版者

公益社団法人日本セラミックス協会

雑誌

日本セラミックス協会学術論文誌 : Nippon Seramikkusu Kyokai gakujutsu ronbunshi (ISSN:18821022)

巻号頁・発行日

vol.113, no.1318, pp.409-412, 2005-06-01

被引用文献数

1 2

---

A novel joining technique of ceramics to metals is presented, in which depositing Ti on ceramics with arc-added glow discharge is used as a prior metallizing technique and then brazing the ceramics to metals by abnormal glow discharge is carried out. The heating temperature of the base metals is easily controlled by varying the operating voltage and barometric pressure. The ions beam from the glow discharge anode is efficiently able to sputterclean the surfaces of the base materials, which thereby improves better Ti-deposited adhesion on the ceramics and the wetting and spreading properties of the filler metal. The thickness of the Ti-deposited layer is readily adjusted in terms of the actual requirement. The vacuum pressure during brazing can be up to 5Pa. The cost and duration of the glow discharge plasma brazing are reduced as compared with the traditional vacuum brazing process. The joining technique developed holds potential for industrial applications leading to high product quality.

著者

大石 修治 望月 圭介 平野 眞一

出版者

公益社団法人日本セラミックス協会

雑誌

日本セラミックス協会学術論文誌 : Nippon Seramikkusu Kyokai gakujutsu ronbunshi (ISSN:18821022)

巻号頁・発行日

vol.102, no.1185, pp.502-504, 1994-05-01

被引用文献数

3 6

---

The growih of emerald crystals by the flux evaporation method in the system Mo0_3 B_20_3 rs reported. The crys tal growth was conducted by heating a mixture of a so lute (3BeO・Al_2O_3・6SiO_2+1wt% Cr_2O_3) and a fiux (MoO_3 B_2O_3) at 1100℃, followed by holding at 1100℃ for 10, 20, 25 and 30h. The evaporation loss of flux decreased gradually with increasing amount of B_20_3 ad ded to Mo0_3 and increased with the holding time. The transparent emerald crystals were grown with the typi cal emerald green color in size up to I mm. The crystal size was dependent on the evaporation loss of flux. Hexagonal thin plate like crystals were grown from an Mo0_3 rich flux containing 0.15 0.60 wt% B_20_3. The plate like crystals were bounded by the {0001} and {1010} faces. In rare cases, the small {1120} faces ap peared. Crystals grown froun the MoO_3 flux were twelve sided prism in shape. Molybdenum trioxide con taining a small amount of B_2O_3 was found to be a suita ble flux for growing plate like crystals of emerald.

著者

新原 皓一

出版者

公益社団法人日本セラミックス協会

雑誌

日本セラミックス協会学術論文誌 : Nippon Seramikkusu Kyokai gakujutsu ronbunshi (ISSN:18821022)

巻号頁・発行日

vol.99, no.1154, pp.974-982, 1991-10-01

被引用文献数

85 1152

---

セラミック系のナノ複合材料は粒内ナノ複合材料,粒界ナノ複合材料,ナノ・ナノ複合材料に分類できる.粒内ナノ複合化と粒界ナノ複合化は酸化物及び非酸化物セラミックスの各種の機械的特性を2〜5倍も向上させる.また,高温における硬度,強度,靭性,クリープ・疲労破壊強度,熱衝撃特性もこの手法により著しく改善される.一方,ナノ・ナノ複合材料は金属のような快削性や超塑性変形性などの新機能を発現する.本稿では,まずナノ複合材料の作製法,ナノ構造の観察結果,機械的特性の改善等について報告した後,ナノ分散粒子の役割について考察し,最後にナノ複合材料の将来を展望する.

著者

斎藤 秀俊 砂山 英樹 田中 教雄 大塩 茂夫

出版者

公益社団法人日本セラミックス協会

雑誌

日本セラミックス協会学術論文誌 : Nippon Seramikkusu Kyokai gakujutsu ronbunshi (ISSN:18821022)

巻号頁・発行日

vol.106, no.1239, pp.1051-1055, 1998-11-01

被引用文献数

17 17

---

Titanium dioxide films were chemically prepared on (001) single-crystal strontium titanate, SrTiO_3, using a vapor deposition apparatus operating under atmospheric pressure with titanium tetra-isopropoxide. At a substrate temperature of 400℃, titanium dioxide grew epitaxially with lateral growth of steps, as well as multinucleation was observed during the initial growth process, i.e., the so-called Stranski-Krastanov growth. As a result, the surface of strontium titanate was completely covered by titanium dioxide steps with an average lateral growth rate of 100 nm/s, followed by multinucleation growth. The nuclei developed in a number of highly oriented crystallites having well defined facets. X-ray diffractometry and transmission electron microscopy revealed that these crystallites consisted of <001>-oriented anatase-type structure.

著者

浴永 直孝

出版者

公益社団法人日本セラミックス協会

雑誌

日本セラミックス協会学術論文誌 : Nippon Seramikkusu Kyokai gakujutsu ronbunshi (ISSN:18821022)

巻号頁・発行日

vol.100, no.1157, pp.38-41, 1992-01-01

被引用文献数

1

---

Thermal Shock tests by arc-discharge heating were carried out on the notched disc specimens of artificial graphite electrodes, while monitoring the change of crack opening displacement (C. O. D.) with time by using a clip gage. The crack abruptly extended from the notch tip at a certain time and stayed at the arc spot in the center of the specimen. The slope θ of the line connecting the origin and C. O. D. just after abrupt extension of the crack, could be determined on each electrode sample within the accuracy of ±10%, independent of notch size. The θ-value thus determined was proposed to be used as a parameter for evaluating the thermal shock resistance of graphite electrode materials and to be named as "thermal shock energy dispersion rate".

著者

金 基孫 作花 済夫 幸塚 広光 横尾 俊信

出版者

公益社団法人日本セラミックス協会

雑誌

日本セラミックス協会学術論文誌 : Nippon Seramikkusu Kyokai gakujutsu ronbunshi (ISSN:18821022)

巻号頁・発行日

vol.100, no.1162, pp.841-846, 1992-06-01

被引用文献数

5

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Using oxide glasses of compositions xNa_2O・(100-x) SiO_2(x=20-50 in mol) and 40Na_2O・(60-y)SiO_2・yAl_2O_3(y=5, 10 in mol) as base glass, Na-Si-O-N and Na-Al-Si-O-N oxynitride glasses were prepared by melting powder mixture of oxide glass and Si_3N_4 or AlN, and the effects of the base oxide glass composition on the glass forming ability, the amount of incorporated nitrogen and the chemical durability of oxynitride glasses were studied. It was found in Na-Si-O-N glasses that the lower Na_2O content is favorable for the formation of nitrided glass, giving larger glass forming regions. Retained nitrogen content decreased with increasing Na_2O content in Na-Si-O-N glasses and with increasing Al_2O_3 content in Na-Al-Si-O-N glasses. Chemical durabilily of Na-Si-O-N glass in-creased with increasing of nitrogen content for any Na_2O content of the base glass. For Na-Al-Si-O-N system, however, nitrogen incorporation increased or decreased chemical durability, depending on the Al_2O_3 content and nitrogen content in the glasses or had no appreciable effect.

著者

中根 久志 青木 早苗 野浪 亨 田中 一彦 森 勝伸 刀根 如人 亀山 哲也

出版者

公益社団法人日本セラミックス協会

雑誌

日本セラミックス協会学術論文誌 : Nippon Seramikkusu Kyokai gakujutsu ronbunshi (ISSN:18821022)

巻号頁・発行日

vol.114, no.1334, pp.838-843, 2006-10-01

被引用文献数

5 11

---

An acid resistant fluoroapatite (FAp) coated titanium dioxide (TiO_2) was synthesized by adding a fluoride ion (F^-) to hydroxyapatite (HAp), in order to avoid dissolution of the HAp at an acidic atmosphere. In this study, different methods of adding F^- to the apatite in a simulated body fluid were tested; one was synthesized by coating a simulated body fluid including Ca^<2+>, PO_4^<3-> and F^- to the TiO_2 (method 1), and another method was by mixing the F^- after coating a simulated body fluid without the F^- to the TiO_2 (method 2). The apatite crystalline phase of the coated TiO_2 was found to increase with F^-, by using a XRD and a FT-IR. The size of crystalline apatite was strongly affected by the method of adding F^-. The size of the crystalline synthesized by method 1 was larger than that by method 2. The photocatalytic activities of the apatite coated photocatalysts to organic substrates such as propionic acid were evaluated using an ion chromatography. The deterioration of FAp coating during photooxidation of the propionic acid with an UV-irradiation was largely suppressed compared with that of the HAp coating.

著者

平井 岳根 村尾 俊裕 Brito Manuel E. 鳥山 素弘 神崎 修三

出版者

公益社団法人日本セラミックス協会

雑誌

日本セラミックス協会学術論文誌 : Nippon Seramikkusu Kyokai gakujutsu ronbunshi (ISSN:18821022)

巻号頁・発行日

vol.110, no.1284, pp.784-788, 2002-08-01

参考文献数

22

被引用文献数

1

---

α'-SiAlON containing Sr, having a large ionic radius, was obtained by hot-pressing. Sr was accommodated in α'-SiAlON in conjunction with Y. The effect of adding Sr to Y-α'-SiAlON on thermal conductivity and mechanical properties was studied. Thermal conductivity decreased from 11.9 W/m・K to 6.2 W/m・K with increasing addition of Sr, due to increasing of phonon scattering both in the lattice and at the grain boundary. Bending strength increased from 460 MPa to 860 MPa with increasing addition of Sr. The increase in bending strength can be associated with grain size refinement and fracture toughness. Fracture toughness also increased with increasing addition of Sr.

著者

中道 俊久 木村 裕之 田崎 和江

出版者

公益社団法人日本セラミックス協会

雑誌

日本セラミックス協会学術論文誌 : Nippon Seramikkusu Kyokai gakujutsu ronbunshi (ISSN:18821022)

巻号頁・発行日

vol.106, no.1234, pp.609-615, 1998-06-01

参考文献数

18

被引用文献数

1

---

金沢大学理工学域Kutani ware is characterized by its overglaze decorating style using Japanese colors. In Kutani industry, it is empirically known that Japanese colors have the tendency of peeling off more often when the body is formed by pressure casting method. In this study, inholnogeneity of porcelain body is examined after measuring the body with applying a X-ray fluorescence analysis to detect the change of chemical composition in the layers from the surface to the center of the body. Converting the obtained values of chemical composition into mineral composition, it was found out that the body formed by pressure casting method becomes highly inhomogeneous; high amounts of clay minerals was observed at the surface and at 1040 μm from the surface, a composition almost the same as the slip within a layer 300-960 μm from the surface, and less clay minerals in the center layer. The result of this experiment also shows that it is possible to improve the homogeneity of the body by controlling the water content of the slip in order to achieve a less mobility of the clay particles.

著者

吉松 英之 武田 耕太郎 三浦 嘉也 矢吹 達美 川端 浩二

出版者

公益社団法人日本セラミックス協会

雑誌

日本セラミックス協会学術論文誌 : Nippon Seramikkusu Kyokai gakujutsu ronbunshi (ISSN:18821022)

巻号頁・発行日

vol.105, no.1218, pp.185-187, 1997-02-01

参考文献数

8

被引用文献数

3 1

---

CaCO_3 powder with high purity was coated with a chelate compound of aluminum corresponded to 0.5 Mass% Al_2O_3. The CIPed compact of the coated powder was sintered at 1500℃ for 2h in air to prepare CaO ceramics ("COAT" specimen). The distribution of Al in the CaO matrix for the COAT was different from that for the CaO ceramics ("MIX" specimen) prepared from the mixture of CaCO_3 and Al_2O_3 powder. The sinterability and slaking resistance of the CaO ceramics were greatly improved by addition of 0.5 mass% Al_2O_3.The relative density and slaking resistance of the COAT specimen were higher than those of the MIX specimen.

著者

下尾 聰夫 早津 俊秀 成澤 雅紀 武田 道夫 市川 宏 瀬口 忠男 岡村 清人

出版者

公益社団法人日本セラミックス協会

雑誌

日本セラミックス協会学術論文誌 : Nippon Seramikkusu Kyokai gakujutsu ronbunshi (ISSN:18821022)

巻号頁・発行日

vol.101, no.1180, pp.1379-1383, 1993-12-01

被引用文献数

10 10

---

The pyrolysis of the low oxygen (1.7% O) SiC fiber prepared by the electron-irradiation curing method has been investigated. The pyrolytic rate was measured with a thermobalance in Ar at temperatures from 1673 to 1973K. The pyrolyzed fiber was examined by X-ray diffraction, SEM observation, specific resistance measurement and tensile test. Lowering of oxygen content in the fiber was found to be effective for the suppression of pyrolysis. The pyrolyzed fiber was composed of β-SiC and amorphous carbon. The growth and coarsening of SiC crystals were observed on the skin of the fiber, while the core was smooth and remained in the microcrystalline state. The tensile strength of the fiber, which was heated at 1973K for 3.6ks, retained 34% of that of the original fiber. The strength was correlated closely with the size of the β-SiC crystal in the fiber.

著者

袖山 研一 目 義雄 神野 好孝 浜石 和人 國生 徹郎 関 博光

出版者

公益社団法人日本セラミックス協会

雑誌

日本セラミックス協会学術論文誌 : Nippon Seramikkusu Kyokai gakujutsu ronbunshi (ISSN:18821022)

巻号頁・発行日

vol.106, no.1231, pp.333-338, 1998-03-01

被引用文献数

7 6

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Preparation and some properties of 20 and/or 30 mass% Shirasuballoons(diameter 6.6, 10.4 and 31.5 μm)added lightweight pottery were studied to develop their high strength with high porosity. Mixed slip of Shirasuballoons and pottery clay was prepared by adding 0.3 mass% water glass. The green compacts consolidated by a slip casting were dried at 110℃ and sintered at 1150-1250℃ for 1h in air. Bulk density of the lightweight pottery was decreased by addition of Shirasuballoons. Closed porosities of the lightweight pottery were almost independent on diameters of Shirasuballoons. Open porosities of the lightweight pottery, however, were affected by the diameter of Shirasuballoon. The open porosity of the lightweight decreased with the addition of 20 and 30 mass% Shirasuballoons in diameter of 6.6 μm, compared with that of without Shirasuballoons, but they increased with the addition of 20 mass% Shirasuballoons in diameter of 10.4 and 31.5 μm. Flexural strength of the lightweight pottery do not decreased with the addition of Shirasuballoons in diameter of 6.6 μm ; compared with that of original pottery clay, but decreased with the addition of Shirasuballoons in diameter of 10.4 and 31.5 μm.

著者

福原 実 藤原 峰一 山口 一格 土井 章

出版者

公益社団法人日本セラミックス協会

雑誌

日本セラミックス協会学術論文誌 : Nippon Seramikkusu Kyokai gakujutsu ronbunshi (ISSN:18821022)

巻号頁・発行日

vol.97, no.1131, pp.1420-1423, 1989-11-01

被引用文献数

4 4

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The formation of Hidasuki, a characteristic red-colored pattern on the surface of Bizen-yaki, was investigated from the viemponats of its mineral composition and coloration. Hematite, corundum and quartz were found in Hidasuki. Corundum was formed regardless of the cooling rate after heat treatment of a mixture of Bizen-clay and 8 to 10 wt% potassium chloride at 1300℃ for 3 h. Hematite was not formed when the mixture was quenched. However, the amount of hexagonal plate like hematite in the heated mixture increased with the lowering of the cooling rate, and the color of the heated mixture became more reddish with the increase of the amount of hematite. The same phase composition, coloration and morphology as those of Hidasuki were obtained when a mixture of Bizen-clay and 8 to 10 wt% potassium chloride was heated at 1300℃ for 3 h followed by cooling at the rate of 0.2 to 0.5℃/min in air.

著者

郡司 天博 谷口 佳範 阿部 芳首

出版者

公益社団法人日本セラミックス協会

雑誌

日本セラミックス協会学術論文誌 : Nippon Seramikkusu Kyokai gakujutsu ronbunshi (ISSN:18821022)

巻号頁・発行日

vol.114, no.1330, pp.492-496, 2006-06-01

被引用文献数

5

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Cyclic and bicyclic oligosiloxazanes were synthesized by the reaction of 1,3-diamino-1,3-di-t-butoxy-1,3-dimethyldisiloxane with 1,1,3,3-tetraisocyanato-1,3-dimethyl-1,3-disiloxane (M-TIDS) in 1:1 and 1:2 molar ratios, respectively. Based on these results, polysiloxazane M-PSZ was prepared by the ammonolysis of M-TIDS in tetrahydrofuran (THF) at 213K. The structure and stability against the gelation of M-PSZ were found to be dependent on the temperature and polarity of the solvents. The molecular weight of M-PSZ was increased by aging a THF solution of M-PSZ at room temperature. A maximum weight average molecular weight of 70000 was observed for M-PSZ, for which a dilute solution was stable over 6 months. Silicon oxynitride was prepared by the pyrolysis of M-PSZ under an ammonia atmosphere. The ceramization process was monitored by infrared and nuclear magnetic resonance spectra, which showed the replacement of a methyl group with an amino group following a condensation reaction to provide silicon oxynitride at 1173K.

著者

申 宇爽 松宮 正彦 邱 法斌 伊豆 典哉 村山 宣光

出版者

公益社団法人日本セラミックス協会

雑誌

日本セラミックス協会学術論文誌 : Nippon Seramikkusu Kyokai gakujutsu ronbunshi (ISSN:18821022)

巻号頁・発行日

vol.110, no.1287, pp.995-998, 2002-11-01

被引用文献数

3 15

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A novel thermoelectric gas sensor of Li- and Na-doped NiO thick film coated with Pt as catalyst on half of its surface, was fabricated for hydrogen gas detection. When this sensor is exposed to air mixed with hydrogen gas, the catalytic reaction heats up the Pt-coated surface, and thermoelectric voltage appears across the hot and cold regions of the oxide film. The thick oxide film was printed on the alumina substrate with a viscous paste, a mixture of the nickel oxide powders doped with alkali ions and organic vehicle. The printed film was fired at 1000℃ for 2h and then the Pt thin film was deposited at room temperature by the rf sputtering method. The non-contact in situ temperature monitor used in this study enables the measurement of voltage signal and the temperature difference separately. The calculated thermopower of the thick oxide film is also discussed.

著者

大道 信勝 神岡 邦和 植田 邦義 松井 光二 大貝 理治

出版者

公益社団法人日本セラミックス協会

雑誌

日本セラミックス協会学術論文誌 : Nippon Seramikkusu Kyokai gakujutsu ronbunshi (ISSN:18821022)

巻号頁・発行日

vol.107, no.1242, pp.128-133, 1999-02-01

被引用文献数

7 35

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The tetragonal-to-monoclinic phase transformation of Y_2O_3-doped tetragonal ZrO_2 polycrystals(Y-TZP)was investigated by annealing at 140°C in hot water. Sintered bodies of Y-TZP were prepared by sintering at temperatures ranging between 1300 and 1500°C, using a 3mol% Y-TZP fine powder, synthesized by means of the hydrolysis method, as a starting powder. X-ray diffraction measurements on the sample surfaces and Rietveld analyses revealed that the amount of cubic phase increased and the Y_2O_3 concentration within the tetragonal phase decreased as the sintering temperature increased. Scanning electron microscopy measurements also showed that the grain size on the sample surfaces increased as the sintering temperature increased. When the sintered bodies were subjected to annealing in hot water, the phase-transformation rate on their surfaces increased as the sintering temperature increased. This behavior can be explained by both the decrease in the Y_2O_3 concentration within the tetragonal phase and the increase in the grain size.

著者

Mackenzie John D.

出版者

公益社団法人日本セラミックス協会

雑誌

日本セラミックス協会学術論文誌 : Nippon Seramikkusu Kyokai gakujutsu ronbunshi (ISSN:18821022)

巻号頁・発行日

vol.101, no.1169, pp.1-10, 1993-01-01

被引用文献数

3 18

---

In the past decade, sol-gel processing has been actively employed for the preparation of new ceramics and for the fabrication of ceramics into many complex geometries. Sol-gel processig is particularly suitable for optical materials. The application of sol-gel technology to the synthesis and fabrication of optical materials is termed "Sol gel optics." A review is presented on the basic principles of the sol-gel process and examples are given for some important materials in sol-gel optics. These include many configurations of silica glass, organic-impregnated glasses, organically modified ceramics (ORMOCERS), ferroelectric thin films, amorphous ferroelectrics, nonlinear optical nanocomposites and gradient index lenses. Some future developments in sol-gel optics are discussed.