TANSO

Fracture verification of a fine grain isotropic graphite containing artificial defect after non-destructive inspection

Sennosuke Sato, Akira Kurumada, Hirosige Suzuki, Eiichi Yasuda

1990 Volume 1990 Issue 141 Pages 2-10
Published: February 25, 1990
Released on J-STAGE: March 01, 2011

DOIhttps://doi.org/10.7209/tanso.1990.2

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Graphite rod specimens containing different sizes of artificial defects, which were simulated with carbonized paper, were manufactured by way of trial experiment and were submitted to a round robin test of nondestructive inspection (NDI). Each position of defect in the rod was almost determined by a series of NDI. This paper deals with de structive test results as the final round robin test. The destructive test was carried out by diametral compression for disk specimens, which were cut from several positions with or without defect in the graphite rod, counting acoustic emission during the compressive loading. In the results, reliabilities of various NDI's and fracture mechanics properties of artificial defect are evaluated.

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Study on Characteristic Structure and Strength of SiC by Heat-Treatment at Atmospheric Condition

Kazuro Kawamura, Shiro Fujimoto, Shotaro Tobisawa, Atsushi Nakahira, K ...

1990 Volume 1990 Issue 141 Pages 11-16
Published: February 25, 1990
Released on J-STAGE: June 28, 2010

DOIhttps://doi.org/10.7209/tanso.1990.11

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A fine powder SiC was formed into SiC specimens of 5×5×30mm under 1500 kgf/cm2 and heated at temperatures from 1000 to 1500°C in air. At the heat treatment temperature (HTT) 1100°C, it was found that the weight of SiC specimens increased to a maximum but the density decreased to a minimum because of oxidation reaction occurred during heating. The SiC specimens heat-treated at 1300°C showed a bending strength of 200 MPa at density of 2.05 g/cm³. This high strength was caused by the development of a thin SiO₂ phase formed by the oxidation of the surface of SiC specimens.
By the use of X-ray diffraction measurement, it was seen that SiO₂ in the oxidationphase was amorphous below HTT 1300°C and gradually crystallized with increasing HTT. Above HTT 1500°C, the oxidation phase came off from inside of SiC specimens accompanying self disintegration caused by the structural difference between surface and inside of SiC specimens.

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Preparation of Carbon Fiber/Carbon Composites by Pressure Carbonization

Matrix from Pitch-Thermosetting Resin Mixtures

Michio Inagaki, Masayoshi Washiyama, Kouji Kobayashi, Mototsugu Sakai

1990 Volume 1990 Issue 141 Pages 17-22
Published: February 25, 1990
Released on J-STAGE: June 28, 2010

DOIhttps://doi.org/10.7209/tanso.1990.17

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The C/C composites were prepared from chopped PAN-based carbon fibers as filler and the mixtures of pitch with either polyethylene terephthalate (PET) or phenol resin with spherical particles as matrix by pressure carbonization under 30 MPa at 650°C. The optical texture of the matrix of C/C composites was able to bring under control in the size of optical units by the addition of PET and phenol resin to pitch. Carbonization of these mixtures under pressure was suggested to help the densification of the composites.

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Preparation of carbon fiber paper/cement composite with electromagenetic shielding effect

Akira Kojima, Sugio Otani, Yosiyuki Sakaniwa, Shigeru Furukawa, Isao K ...

1990 Volume 1990 Issue 141 Pages 23-29
Published: February 25, 1990
Released on J-STAGE: June 28, 2010

DOIhttps://doi.org/10.7209/tanso.1990.23

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Electromagnetic schielding effect of carbon fiber paper/cement composite (CFRC) was investigated. The CFRC plates were prepared by the lamination of various carbon fiber (CF) paper preimpregnated with cement paste, and were cured in water. The matrix of CFRC was consisted of poltrand cement and alumina cement. The CF content of the CFRC prepared was 3-4 vol%, the bulk density being 1.8-2.0 g/cm³.
To increase the electromagnetic shielding effectiveness of the CFRC, it was necessary (1) to use CF with large length, (2) to add some conductive graphite or carbon black powder into the cement, and (3) to use highly conductive CF. The specific resistance of the CFRC prepared from CF paper with a fiber length of 10mm was 0.8 Ω.cm, and its electric shielding effectiveness was as high as 58 dB (frequency; 250 MHz). On the other hand the CFRC prepared from CF filament of long fiber showed a specific resistance of 0.7 Ω.cm and a higher electric shielding effectiveness of 60dB (250 MHz).
From these results it was found that CFRC using CF paper has a high degree of electromagnetic shielding effect.

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Study of the structures of intercalate layer in metal chloridegraphite intercalation compounds by using EXAFS and XANES

Z.D. Wang, M. Ohira, M. Inagaki, N. Kosugi, K. Yamazaki, H. Kuroda

1990 Volume 1990 Issue 141 Pages 30-37
Published: February 25, 1990
Released on J-STAGE: June 28, 2010

DOIhttps://doi.org/10.7209/tanso.1990.30

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The structures of intercalate layer in several metal chloride-graphite intercalation compounds (GIC_s) were studied by the analysis of extended X-ray absorption fine structure (EXAFS) and X-ray absorption near-edge structure (XANES). The intercalated CuCl₂ in CuCl₂-GIC maintains a similar layer structure with long-range-order to that in anhydrous CuCl₂ crystal. The structure of intercalated iron chloride in its GIC obtained in FeCl₃-KCl molten salt is similar to that in the ternary GICs with iron chloride and nickel chloride, which are synthesized by using either a mixture of FeCl₃ and NiCl₂ or a FeCl₃-NiCl₂-KCl molten salt. In these ternary compounds, iron and nickel chlorides intercalated have a long-range-order in their layers and seem to exist in separated domains.

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A Study on the Structure of Pellet Formed from Polyacrylonitrile Carbon Prepared between Montmorillonite Lamellae

Naohiro Sonobe, Takashi Kyotani, Akira Tomita, Yoshihiro Hishiyama

1990 Volume 1990 Issue 141 Pages 38-44
Published: February 25, 1990
Released on J-STAGE: June 28, 2010

DOIhttps://doi.org/10.7209/tanso.1990.38

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A carbon prepared from carbonization of polyacrylonitrile between montmorillonite lamellae (IPC) can be pelletized without a binder, The pellet of IPC was formed at about 250 kg/cm², and then it was subjected to heat-treatment at various temperatures up to 2960°C. The graphitizability and orientation of resulted pellet were determined by TEM, SEM observations, X-ray diffraction and magnetoresistance measurements. The meansquare displacement of carbon atoms for the pellet heat-treated at 2960°C is so small that the graphitizability of pellet is very high. The value of transverse magnetoresistance for the pellet is much smaller than expected from its high graphitizability, partly because of the size effect of IPC. The degrees of orientation determined by X-ray diffraction and by magnetoresistance measurements were 23-36° and 19-36°, respectively.

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[title in Japanese]

[in Japanese], [in Japanese]

1990 Volume 1990 Issue 141 Pages 45-55
Published: February 25, 1990
Released on J-STAGE: June 28, 2010

DOIhttps://doi.org/10.7209/tanso.1990.45

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[title in Japanese]

[in Japanese]

1990 Volume 1990 Issue 141 Pages 56-69
Published: February 25, 1990
Released on J-STAGE: June 28, 2010

DOIhttps://doi.org/10.7209/tanso.1990.56

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