著者

Satoshi YOSHIDA

出版者

The Ceramic Society of Japan

雑誌

Journal of the Ceramic Society of Japan (ISSN:18820743)

巻号頁・発行日

vol.128, no.7, pp.340-348, 2020-07-01 (Released:2020-07-01)

参考文献数

60

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The indentation test using a sharp diamond indenter, such as a Vickers indenter, has been long employed for comparing mechanical properties among various glass compositions, because of its simple procedure and easy operation. However, mechanisms of permanent deformation and crack nucleation in glass are far from simple. This has made it difficult to understand what controls the threshold load for cracking in a certain glass during indentation. In this review, the author’s works on indentation-induced deformation and cracking in glass are introduced, and relevant issues on the indentation technique are discussed. Especially, it is pointed out that permanent densification of glass under the indenter is a key phenomenon which controls the following cracking event. Further, it is also shown that the micro-photoelastic observation system, by which the indentation-induced stress field can be visualized, and the indentation microscope, which enables one to measure the contact area between glass and the indenter, are powerful tools to stimulate new and fresh ideas for improving mechanical properties of glass.

著者

北條 純一 前田 英明 加藤 昭夫

出版者

The Ceramic Society of Japan

雑誌

Journal of the Ceramic Society of Japan (日本セラミックス協会学術論文誌) (ISSN:09145400)

巻号頁・発行日

vol.96, no.1116, pp.842-846, 1988-08-01 (Released:2010-08-06)

参考文献数

10

被引用文献数

1 1

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Amorphous silicon nitride powder (particle size: 0.04μm) obtained by the vapor phase reaction of Si(CH3)4-NH3 system was compacted into pellet and heat-treated in N2 to investigate the crystallization behavior. The amorphous powder crystallized to 100% α-Si3N4 by the heat treatment for 1h at 1550°C. The equiaxed crystalline particles having the size of 1-2μm were obtained when powder was compacted, whereas acicular particles were produced when powder was not compacted. When Si3N4 powder was used as powder bed which covered pellet, the crystalline particles grew extensively and the crystallinity increased with a decrease in the packing fraction of particles in pellet. The heat-treated powder with a low crystallinity consisted of fine amorphous particles and coarse crystalline particles. The crystallization seemed to proceed by a vapor phase growth mechanism, in which SiO vapor takes part as silicon carrier between amorphous particles and crystalline ones. When BN powder was used as powder bed, the crystallization and grain growth were retarded, and the crystal phase contained a small amount of β-Si3N4. Crystallization inhibitor, e. g. boron oxide, may have penetrated into pellet from BN powder.

著者

中平 敦 坂本 清子 山口 俊郎 木島 弌倫 岡崎 正之

出版者

The Ceramic Society of Japan

雑誌

Journal of the Ceramic Society of Japan (日本セラミックス協会学術論文誌) (ISSN:09145400)

巻号頁・発行日

vol.107, no.1241, pp.89-91, 1999-01-01 (Released:2010-08-06)

参考文献数

9

被引用文献数

5 7

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Hydroxyapatite whisker and platelet were synthesised by the hydrolysis of alpha-tricalcium phoshate (α-TCP) in H2O system and etanol/H2O system at 70°C and atmospheric pressure, thus avoiding severe processing condition, such as in hydrothermal synthesis. The hydroxyapatite prepared by this process was analysed by X-ray diffractometry and transmission electron microscopy observation. The effect of ethanol addition into H2O on the hydrolysis of α-TCP to hydroxyapatite was also examined. The hydrolysis rate of α-TCP to hydroxyapatite was inhibited in the ethanol/H2O system. It was found that the morphology and the aspect ratio of hydroxyapatite could be controlled by adding ethanol into H2O during the hydrolysis reaction of α-TCP.

著者

吉村 昌弘 早川 信 宗宮 重行

出版者

The Ceramic Society of Japan

雑誌

Journal of the Ceramic Society of Japan (日本セラミックス協会学術論文誌) (ISSN:09145400)

巻号頁・発行日

vol.97, no.1131, pp.1339-1347, 1989-11-01 (Released:2010-08-06)

参考文献数

42

被引用文献数

3 4

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The reactions between TiC or TiN powder and H2O have been studied at 200°-650°C under 100MPa. The reaction of TiC with H2O above 400°C for 3h yielded anatase, CH4, CO2 and H2, and above 500°C rutile was formed additionally. TiN powder with an average grain size of 1.4μm reacted with H2O above 290°C to yield anatase, NH3 and H2, while TiN powder of 9μm reacted H2O above 480°C and yielded rutile, NH3 and H2. The oxidation rate calculated from the weight gain was compared with that from various model kinetic equations. In TiC the rate was best described by the Avrami-Erofeev equation (n=1.3), while the core-shrinking model fitted as well. This suggests that the reaction was controlled by the phase boundary reactions. In TiN the Jander-type model was the best, which suggests that the reaction was controlled by the diffusion through the oxide scale. An Arrhenius plot of the rate constants gave an apparent activation energy of 98kJ/mol. The difference of reaction mechanism between TiC and TiN is attributed to the difference in the gaseous species of reaction products.

著者

前田 香雪

出版者

The Ceramic Society of Japan

雑誌

大日本窯業協會雑誌 (ISSN:03669998)

巻号頁・発行日

vol.10, no.109, pp.Plate1-Plate1, 1901

著者

奥野 雅史 迫川 邦俊 光藤 裕之

出版者

The Ceramic Society of Japan

雑誌

Journal of the Ceramic Society of Japan (日本セラミックス協会学術論文誌) (ISSN:09145400)

巻号頁・発行日

vol.98, no.1136, pp.370-376, 1990-04-01 (Released:2010-08-06)

参考文献数

19

被引用文献数

1 1

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Recently, Ri, Hamano and Nakagawa have experimentally revealed adsorption effect transistor characteristics of ZnO sinters [Yogyo-Kyokai-Shi, 93, 230-36 (1985); Yogyo-Kyokai-Shi, 94, 419-24 (1986)]. These results are computationally simulated for the sinters having the local states of bulk donors, grain boundary interface acceptors, surface acceptors and thermally desorbable surface donors in conformity with Fermi-Dirac's law for electron occupation, Poisson's equation for potential distribution and charge neutrality condition. Each parameter of the local states is concurrently obtained within the reasonable value. The potential barrier at necks with radius larger than the surface Debye length is weirlikely formed because of the interface and so independent of the surface states (open-out necks). The potential barrier at necks with radius smaller than the surface Debye length is formed in the shape of a saddle because of both the surfaces and the interfaces and so depends on the neck radius and the surface states in addition to the interface states. The bulk resistivity of sinters is obtained by the effective medium approximation for random networks in consideration of the neck radius distribution. The clusters bonded by the open-out necks percolate always through the sinters above 85% in the relative density. On the basis of the above, the hysteresis of bulk resistivity and adsorption effect transistor responses to admission of propane gas are analyzed.

著者

Yuji NAKABAYASHI Satoru YAMADA Satoshi ITOH Takeshi KAWAE

出版者

The Ceramic Society of Japan

雑誌

Journal of the Ceramic Society of Japan (ISSN:18820743)

巻号頁・発行日

vol.126, no.11, pp.925-930, 2018-11-01 (Released:2018-11-01)

参考文献数

32

被引用文献数

12

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Single-crystal thin films of gallium oxide (Ga2O3), an ultra-wide bandgap semiconductor, were fabricated on c-plane sapphire by mist chemical vapor deposition (mist CVD). The grown α-Ga2O3 thin films had low surface roughness, and we characterized their initial crystal growth phase by using atomic force microscopy and X-ray diffraction. By varying the precursor concentration, we changed the surface roughness and crystallinity of the thin films. The lattice constants of the α-Ga2O3 thin films almost matched those of the single crystal in the initial growth phase. We also found that these thin films grew hetero-epitaxially. Finally, mist CVD might have a very short incubation time in this system.

著者

加藤 昌宏 鵜沼 英郎 高橋 実

出版者

The Ceramic Society of Japan

雑誌

Journal of the Ceramic Society of Japan (日本セラミックス協会学術論文誌) (ISSN:09145400)

巻号頁・発行日

vol.108, no.1257, pp.478-481, 2000-05-01 (Released:2010-08-06)

参考文献数

14

被引用文献数

9 9

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In the aim of the understanding of the coloration mechanism in Cr-doped inorganic pink pigments, the valences of Cr dopant in sphene-type (CaTiSiO5-CaSnSiO5), perovskite-type (CaTiO3-CaSnO3) and rutile-type (TiO2-SnO2) matrices were investigated by use of X-ray photoelectron spectroscopy (XPS). The valences of chromium were directly related to the color of the pigments. The valences were dependent on the Ti/Sn ratio in the mother crystals. Results of XPS showed that chromium ions doped in CaSnSiO5 and CaSnO3 matrices existed Cr4+, causing reddish purple color. With substitution of Ti for Sn in these matrices, the fraction of trivalent chromium increased and the color changed from reddish purple through purple red, red brown and finally to brown. A similar valence change of chromium was observed in the rutile-type pigments that changed lilac through brown to ocar colors. Purple red color was achieved in 2mol% Cr-doped sphene- and perovskite-type pigments containing 20mol%Ti.

著者

世良 末素人

出版者

The Ceramic Society of Japan

雑誌

大日本窯業協會雑誌 (ISSN:03669998)

巻号頁・発行日

vol.38, no.449, pp.279-283, 1930

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工業製品に對する規格統一は、世界的に其の機運熟し、我國に於ても、商工省に日本工業品規格統一調査會を設けて、其の運動の中心機關をなして居るが、未だ寡聞にして、材料分析法に關する規格の統一されたるを聞かず、從つて各工揚・會社・學校等に於ける分析法も、區々街々にして、殊に硅酸分の測定の如きデリケートなるものは其の方法乃至操作の如何によりては可成の相違あるを見る。<br>余もとより淺學菲才、殊に分析を專業とせるものにあらざれば、次に示さんとする亞米利加材料試驗所 (The American Society for Testing Materials) の粘土分析法の規絡に對し、欽仰せるものにもあらず、又、評論するものにもあらず、只余自身の參考にさなんと譯したるものを其の儘、亞米利加にはかゝる規格のある事を紹介せんとするに過ぎず。幸に分析術修學中の諸氏の幾分の參考ともならば望外である。

著者

Katsunori KOSUGE Atsushi YAMAZAKI Atsumu TSUNASHIMA Ryohei OTSUKA

出版者

The Ceramic Society of Japan

雑誌

Journal of the Ceramic Society of Japan (ISSN:09145400)

巻号頁・発行日

vol.100, no.1159, pp.326-331, 1992-03-01 (Released:2010-08-06)

参考文献数

15

被引用文献数

32 59

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In order to synthesize well-crystallized magadiite and kenyaite as a single phase in a short reaction time, amorphous silica was hydrothermally reacted with alkaline solutions in the temperature range from 150°C to 200°C. From a suspension containing SiO2 and NaOH with molar ratios of H2O/SiO2=18.5 and NaOH/SiO2=0.23, magadiite was formed after a reaction time of 48 h at 150°C or after 18h at 170°C. The formation of Na-kenyaite, however, required 6h at 200°C. Then, KOH and K2CO3 were used to lower the formation temperature of kenyaite. K-kenyaite was synthesized after 16h at 185°C from a suspension with molar ratios of H2O/SiO2=18.5 and KOH/SiO2=0.23. Furthermore, (Na, K)-kenyaite was formed after 48h at 150°C or after 24h at 170°C from suspensions with molar ratios of H2O/SiO2=18.5, NaOH/SiO2=0.23 and NaOH/K2CO3=0.95-23. Magadiite and kenyaite were formed through a difinite induction period after dissolution of amorphous silica.

著者

SUZUKI Yoshikazu MORIMOTO Masafumi

出版者

The Ceramic Society of Japan

雑誌

Journal of the Ceramic Society of Japan (ISSN:18820743)

巻号頁・発行日

vol.118, no.1381, pp.819-822, 2010-09

被引用文献数

21

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Porous ceramics based on refractory double oxides are promising for the next-generation diesel particulate filter (DPF) materials. Similarly to aluminum titanate (Al2TiO5), MgTi2O5 has a pseudobrookite-type crystal structure with low thermal expansion coefficients among oxides. Since MgTi2O5 has higher stability of pseudobrookite phase than Al2TiO5, it is expected that MgTi2O5-based materials are suitable for the next-generation DPF materials. In this study, porous MgTi2O5/MgTiO3 composites have been prepared by in situ processing (viz. reactive sintering) at 1000–1200°C. Porous MgTi2O5/MgTiO3 composites with very narrow pore-size distribution at the diameter of ∼1 µm were obtained by the pyrolytic reactive sintering at 1000–1100°C. Internal pore-structure was characterized by mercury intrusion–extrusion porosimetry.

著者

山内 俊吉

出版者

The Ceramic Society of Japan

雑誌

大日本窯業協會雑誌 (ISSN:03669998)

巻号頁・発行日

vol.45, no.533, pp.279-299, 1937

被引用文献数

3

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ポルトランドセメントのセリツト部分は4CaO・Al₂O₃・Fe₂O₃なる化合物であると唱へてゐるが尚ほ不可解な點が多く理論的或は技術的立場から今一段の研究が希望されてゐる現状である。<br>著者はこの樣な見界からセリット部分の研究に手を染めることにした。<br>そこでセリット部分の研究に先だつて確めておかねばならぬ基礎的な部分はCaO, Fe₂O₃, CaO-Al₂O₃系CaO-Fe₂O₃系等に關する正しい知識である。 CaO-Al₂O₃系については著者等は度々本統に報告してきたので本報ではCaO, Fe₂O₃, CaO-Fe₂O₃系等についての結果を報告することにした。<br>即ち本報に於てはCaCO₃, Fe₂O₃等の加熱による構造の攣化, CaCO₃:Fe₂O₃が3:1, 2:1, 1:1, 1:2の4種調合物を1000-1470℃の各種温度で燒成してCaO-Fe₂O₃系の化合物の種類等を顯微鏡及びX線的に確かめ最後にCaO-Fe₂O₃系の純化合物の水和作用をしらべた結果を報告した。<br>その結果は大約次の様であつた。<br>(1) 2CaO₃・Fe₂O₃等は著者の様な實驗條件では温度によつて構造の變化なしと考へて差支えない。<br>(2) CaO-Fe₂O₃系には2CaO・Fe₂O₃, CaO・Fe₂O₃の二種の化合物が存在する。 之等の合成に於ては著者の實驗條件では温度による變態及び解離は考へなくてもよい。<br>(3) 2CaO・Fe₂O₃は熔融點以下で或る量のCaOと固溶體を作り熔融點以上では2CaO・Fe₂O₃とCaOとに解離することを新に發見した。<br>(4) 2CaO・Fe₂O₃は水を加ふれば可なり早く水和する。 20日に於てX線的には殆んど原化合物は認められない位に水和し盡してゐることが分る。 2CaO・Fe₂O₃は水と作用し水セメント比が普通工事程度の水量の時は水和生成物として2CaO・Fe₂O₃・5H₂Oを作る。 この水和物は多量水を以て抽出すれば加水分解を起し次第に低石灰化合物となり最後にはCa(OH)₂とFe₂O₃・nH₂Oとになる。<br>(5) CaO・Fe₂O₃は水和しない。<br>終りに臨み本研究を行ふに當り直接御指導御助言を賜はつた恩師東京工業大學教授近藤清治博土並に本研究を熱心に援助された近藤教授研究助手小西幸平君に對し衷心の謝意を捧るぐ次第である。

著者

中條 金兵衞

出版者

The Ceramic Society of Japan

雑誌

大日本窯業協會雑誌 (ISSN:03669998)

巻号頁・発行日

vol.47, no.562, pp.535-542, 1939

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この第6報は, 第5報に詳説したAN型新風篩器に就て決定さるべき諸要項並びに操作, 及びそれ等の實用的利用法に關する記述で, その要約を順を追つて箇條書きに列擧すると次の如くである.<br>(i) 先づ粉末の細かさを知る爲に, それを粒子の大きさに從つて分割する際, 限界に立つべき粒子の徑を顯微鏡下に測定する爲のプレパラート作製法の簡單にして恒常性ある方法を紹介説明した.<br>(ii) 次に粒子の大きさを實測するに際して, 如何なる粒子徑の定義に依るを簡明且合理的とするかを檢討し, 結局200乃至400個限界粒子の長さ<i>l</i>, 幅<i>b</i>を測定し,<br>(<i>l</i>+<i>b</i>/2)_m=<i>l_m</i>+<i>b^w</i>/2<br>によつて表示するの實用性を認めた.<br>(iii) 限界粒子徑の大きさを如何樣にとるかに就て, 諸家の研究に徴し, 筆者の研究に俟つて,<br>(<i>l</i>+<i>b</i>/2)<i>_m</i>=15.0μ<br>と決定した.<br>(iv) 試驗に供する粉末の量に關し, 50g又はそれ以上にとるべしといふ一部の主張に批判を加へ, 精度と時間とを考慮した測定器固有の量を選定すべきことを述べ, AN型に於ては20gを適當とする結論に達した.<br>(v) 風篩を打切るべき終點の決定は, 風篩器の性能に應じてなさるべきで, AN型は分離能力大なる點よりして, 10分間の吹上げ量1%以下となる時刻を以てすることが出來る. 從つて風篩時間は40-50分にて足る.<br>(vi) 風篩筒内壁には多數粒子附着し, これが試驗精度を低める因をなすので, 測定中一度送風を斷つて内面を清掃する必要はあるが, それは唯々一囘にて足ることを確めた.<br>(vii) 實用的風篩器は日常的な試驗條件, 例へで室温, セメント比重等の變動に因つても, その精度に左程の影響を受けはいことが必要で, 實際, 限界粒子徑15μに對して常温の開き10℃は0.21μ, 比重1.2%の不同は0.18μの誤差を起すに過ぎぬ.<br>(viii) AN型風篩器はその構造の堅牢, 簡潔と操作の單純, 確實との爲, 未經驗者にても容易に着手し得て, 唯々1囘にてその試驗成績は0.3%内外の精度に達することが出來る.<br>(ix) 豫備試驗に於て, セメント風篩の限界粒子徑が15.0μを與ふる樣に風量を豫め決定する爲には普通, ガスメーターを使用するが, 精確な測定は厄介である. 確實にして實用的な方法は, 標準粉末の殘滓量が規定の數値に達する樣な風量を發見するに在り, この方法の價値を述べた.<br>(x) AN型にて風篩したセメントの殘滓より, 比表面積を直接, 容易に求め得る2つの表を作製し, その利用法を示した.<br>(xi) AN型風篩器の考案, 操作の決定には豫め要望さるる諸原則を樹て, これに適合するやう研究を進めて來たのであるが, 第5, 6報を省察して, その略々充されてゐることを知ることが出來た.<br>要するに, 以上第5, 6報は第1, 2, 3, 4報に於ける基本的研究の基礎上に立つて, これを實用化する目的を以て爲された探究に關するもので, 適切なる装置と操作とによつて40-50分にして眞値に近ぎ表面積を求め得ることを叙述したのである.<br>尚, この試驗研究に多大の御援助と御指導とを賜つた淺野セメント技術顧問藤井光藏氏に深甚の謝意を表する次第である.

著者

大野 正巳 近藤 清治

出版者

The Ceramic Society of Japan

雑誌

大日本窯業協會雑誌 (ISSN:03669998)

巻号頁・発行日

vol.47, no.553, pp.3-7, 1939

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本報に於て著者等は能登半島一帶に多量に埋藏されて居る珪藻土の産状を, 關係産地の地質學的從來の研究を引照綜合しこれに著者等の實地踏査の際に採取したる試料に就て分析せる化學成分より説明し, その産地として代表的なる輪島及和倉附近の珪藻土に就て研究せる顯微鏡的觀察の結果を報告してその一般的品質に就て論じた。<br>終に本研究を發表するに當り, 實驗に關し多大なる御援助を賜りし東京工業大學窯業學科末野悌六・山内俊吉兩氏, 地質學的方面に御教示を得たる第四高等學校望月勝海氏竝に東大地震研究所大塚彌之助氏に深き感謝の意を表する。尚本研究の一部は著者の一人大野が文部省内地研究員として東京工業大學窯業學科に留學中行へる研究の一部であることを附記する。

著者

Hamid SARRAF Reinhard HERBIG

出版者

The Ceramic Society of Japan

雑誌

Journal of the Ceramic Society of Japan (ISSN:18820743)

巻号頁・発行日

vol.116, no.1357, pp.928-934, 2008 (Released:2008-09-01)

参考文献数

19

被引用文献数

2 5

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This paper describes a convenient and rapid colloidal measuring process of electrokinetic (ζ-potential, ESA signal) properties of the relatively concentrated aqueous suspensions of a submicron α-Al2O3 powder with the anionic polyelectrolyte (Dolapix CE64) dispersant by applying of an advanced electrokinetic sonic amplitude "ESA" technique without dilution. In addition to ESA measurement, the following measurements were also applied: the viscosity, sedimentation, Bingham yield value and prticle size distribution. Very good agreement is observed from the relationship between the electrokinetic (ζ, ESA) values, the viscosity and its pH dependence for each concentrated α-Al2O3 suspension with different amounts of dispersant. The results indicate that the amount of 0.4 mass% Dolapix CE64 is the optimum amount of dispersant that can cause electrosteric effect and decreases mean (d50) particle size of different concentrated (2 vol% and 45.68 vol%) α-Al2O3 suspensions near to the original size. Finally, the study illustrates that Dolapix CE64 is an effective dispersant at all solid loading conditions.