Journal of the Ceramic Society of Japan
Online ISSN : 1348-6535
Print ISSN : 1882-0743
ISSN-L : 1348-6535
121 巻, 1419 号
(November)
選択された号の論文の9件中1~9を表示しています
Special Article: The 67th CerSJ Awards for Academic Achievements in Ceramic Science and Technology: Review
  • Hidero UNUMA
    2013 年 121 巻 1419 号 p. 919-924
    発行日: 2013/11/01
    公開日: 2013/11/01
    ジャーナル フリー
    Ceramic synthesis in aqueous solutions, referred to as aqueous solution processing in this article, is attracting much attention as its high potentiality of controlling morphology, composition, and functions are revealed by recent pioneering works. A diverse range of chemical reactions and physical phenomena are available to create new materials that has been difficult to be processed by other techniques. Mild processing conditions inherent to aqueous solution processes have made it possible to define morphology and composition of the products in elaborate ways, to hybridize ceramic with organic substances or metal nanoparticles, and to contribute to economical and environmental issues of ceramic industry. Among many beneficial aspects of aqueous solution processing, this article spotlights the categorization of chemical reactions used for thin film deposition, up to date outlines of enzyme-mediated techniques, and recent attempts of the application. The products of aqueous solution processing should find applications in vast fields of technology as its inherent advantages are explored.
Papers
  • Anton TRNÍK, Igor ŠTUBŇA, Radomír SOKOL&Aa ...
    2013 年 121 巻 1419 号 p. 925-929
    発行日: 2013/11/01
    公開日: 2013/11/01
    ジャーナル フリー
    Two green ceramic materials were studied during heating from room temperature to 1100°C. One material (CG) contained clay (60 mass %) and grog (40 mass %), while the other (CGF) contained clay (60 mass %), grog (20 mass %), and fly ash (20 mass %). The investigated green ceramics are a mixture of minerals (kaolinite, illite, muscovite, calcite, and quartz). The main improvement of the mechanical properties between 20 and 300°C is due to the liberation of physically bound water. In the temperature region from 300 to 900°C very small changes of the sample volume are observed, and Young’s modulus slightly increases. From 900 to 1100°C, the sintering and creation of new phases causes a large shrinkage of the sample volume, and Young’s modulus dramatically increases its value. The total shrinkage of the sample volume during heating is ~6% for CG and ~24% for CGF. The relative change of Young’s modulus is ~220% for CG and ~190% for CGF.
  • Haruhiko MORITO, Hisanori YAMANE
    2013 年 121 巻 1419 号 p. 930-933
    発行日: 2013/11/01
    公開日: 2013/11/01
    ジャーナル フリー
    SiC was prepared by heating a mixture of graphite and Si powders with sodium over the temperature range 1173–1273 K and was characterized via X-ray diffraction, electron microscopy, and electron diffraction. The sample prepared at 1273 K exhibited aggregates of truncated hexagonal pyramid-shaped SiC crystals that were a few hundreds nanometers in size, as evidenced by scanning electron microscopy. Transmission electron microscopy and electron diffraction revealed that the crystals contained stacking faults along [111] of the cubic lattice of β-type.
  • Masaki KATAYAMA, Jun NAKAKUKI, Jae-Hwan PEE, Yuichi KOBAYASHI
    2013 年 121 巻 1419 号 p. 934-939
    発行日: 2013/11/01
    公開日: 2013/11/01
    ジャーナル フリー
    Cordierite ceramics were prepared from several types of kaolin powders and talc powders having various median particle size with nanometer-sized alumina sol. Powder mixtures were uniaxially pressed, followed by cold isostatic pressing to make thin compacts. Crystal orientation of talc particle and resultant cordierite were evaluated using the X-ray diffraction profile measured on the uniaxially pressed surface of calcined compacts and sintered compacts, respectively. Coarser talc powders above 3 µm aligned their c-axis in vertical to the uniaxially pressed surface of the calcined compact during uniaxially pressing, owing to highly anisotropic tabular shape. The crystal orientation of resultant cordierite increased with an increase in the crystal orientation of talc powders on the pressed surface. This result indicated that the c-axis of cordierite crystal preferably oriented vertically to the c-axis of talc particle oriented. Using the combination of kaolin powders below 5 µm and talc powders having median particle size between 3 and 5 µm, densely sintered cordierite, having a relative density of 95% and high crystal orientation of approximately 85% [I110/(I110+I002)], could be obtained.
  • Jang-Hoon HA, Eunji OH, In-Hyuck SONG
    2013 年 121 巻 1419 号 p. 940-945
    発行日: 2013/11/01
    公開日: 2013/11/01
    ジャーナル フリー
    Recently, porous ceramic membranes have become an interesting subject due to their outstanding thermal and chemical stability. Among the many types of ceramics, as diatomite is inherently porous and irregular, it is worthwhile to investigate the relationship between the characteristics of sacrificial templates and porous microstructures after sintering. Therefore, sintered diatomite membranes were prepared with 8 µm solid polymer spheres, 20 µm solid polymer spheres, wheat starch, and light clusters of aggregated carbon nanotubes while varying the amount of sacrificial template material by dry pressing at 25 MPa. The results show that the characteristics of the sacrificial templates, e.g., the rigidity, directly affect the pore characteristics and accordingly determine the permeability of sintered diatomite membranes. Also, we discuss whether the largest pore sizes and average pore sizes of the sintered diatomite membranes reflect the actual permeability appropriately.
  • Atsushi SAKUDA, Akitoshi HAYASHI, Yorinobu TAKIGAWA, Kenji HIGASHI, Ma ...
    2013 年 121 巻 1419 号 p. 946-949
    発行日: 2013/11/01
    公開日: 2013/11/01
    ジャーナル フリー
    Elastic modulus is an important factor of solid electrolytes for an all-solid-state battery as a next-generation battery. In this study, Young’s moduli of dense pellets of the Li2S–P2S5 glass solid electrolytes prepared by room temperature pressing and hot pressing were investigated. The Young’s moduli of Li2S–P2S5 hot-pressed pellets measured by ultrasonic sound velocity measurements were 18–25 GPa and those of cold-pressed pellets were about 14–17 GPa. The compression test was also done to determine Young’s modulus. The Young’s modulus of Li2S–P2S5 glasses increased with increasing the Li2S content in both hot press and cold press pellets. The Young’s moduli were lower than those of oxide based solid electrolytes.
  • Ievgen SOLODKYI, Sky Shumao XIE, Ting ZHAO, Hanna BORODIANSKA, Yoshio ...
    2013 年 121 巻 1419 号 p. 950-955
    発行日: 2013/11/01
    公開日: 2013/11/01
    ジャーナル フリー
    Hard boron suboxide (B6O) is a difficult-to-consolidate ceramic material that requires extreme processing conditions to achieve sintering activation and is only consolidated readily at high pressures above 4 GPa. In this contribution, for the first time, we report the consolidation of hard and tough laboratory-synthesized B6O by the spark-plasma sintering (SPS) technique. The density of SPS-sintered specimens of >= 98% is reported, and an optimal combination of 34 GPa hardness and 4 MPa·m1/2 fracture toughness is achieved by controlling the amount of glassy phase boron oxide (B2O3) with an appropriate SPS set up. The effects of the type of protection used, i.e., graphite die lined only with graphite foil, BN coating, or tantalum foil, on the phase compositions and properties of bulk were studied. Finally, composites of boron suboxide and boron carbide, B6O–xB4C (x = 0, 3, 5, 10, 20, 40 wt %) were fabricated by SPS, and a significant improvement in the mechanical properties was achieved. Results showed that dense B6O–10 wt %B4C composite material with a hardness above 40 GPa and a fracture toughness of 4.8 MPa·m1/2 were obtained.
Technical report
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