TANSO

X-ray Parameter Changes in Core-support Carbon Material for VHTR induced by Very Long Hour Heat-treatment

Tamotsu Saito, Hideto Matsuo

1983 Volume 1983 Issue 112 Pages 2-5
Published: January 20, 1983
Released on J-STAGE: June 28, 2010

DOIhttps://doi.org/10.7209/tanso.1983.2

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The effect of heat-treatment up to 1200°C for residence times up to 6000 hrs on X-ray parameters, d₍₀₀₂₎and L_{c (002)}, of a carbon material (SIG-B) baked at around 1000°C was studied.An effective activation energy for these parameter changes was calculated to be 120-130 kcal/mole by the“Super-imposing method”.L_{c (002)}growth was observed in these heat-treatments, but the change in d₍₀₀₂₎showed that the structure remained turbostratic and the activation energy obtained was the value reported for pre-graphitization process.
On the basis of this effective activation energy obtained, an estimation was made on the structural changes in this carbon when it was used in the core support material of VHTR: d₍₀₀₂₎ changes slightly and the structure remains turbostratic, but L_{c (002)}grows from 32Å of the original to 46Å after the use for 20 years at 1000°C in VHTR environment.

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Morphological Feature of Carbon Blacks Prepared by Explosion of PETN/Naphthalene and PETN/Pyrene Mixtures

Kazuro Kawamura, Shiushichi Kimura, Eiichi Yasuda

1983 Volume 1983 Issue 112 Pages 6-12
Published: January 20, 1983
Released on J-STAGE: June 28, 2010

DOIhttps://doi.org/10.7209/tanso.1983.6

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Carbon blacks were prepared by explosion of a PETN/naphthalene mixture and a PETN/pyrene mixture.Their features have been studied through the determination of surface areas by BET technique and the electron microscopic observation of structural change by heat treatment up to 2800°C.
Morphological feature differed not from non-explosive components but from the ratio of mixing of explosive component which caused complete explosion or incomplete explosion. The 40% PETN/60% naphthalene or the 35% PETN/65% pyrene mixture incompletely exploded, and the carbon blacks formed showed in a variety of particle shapes.Among others the particles in a large diameter and/or with hollows were noticeable.When the particles were heated up to 2800°C, the radial arrangement in layer planes was observed in the large particles formed from the 35% PETN/65% pyrene mixture.While the 50% PETN/50% naphthalene or the 45% PETN/55% pyrene mixture completely exploded and their carbon black particles formed were uniform relatively.When they were heated at 2800°C, each center of particles was largely hollow.This suggests that the packing density of the layer planes (or molecules) about the particle center is low.
From the determination of surface areas of particles, it was found that the areas were 20-50m²/g in the range of incomplete explosion and in the range of complete explosion, the areas enlarged remarkably as the explosion became strong.

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Thermal Shock Resistance and Thermal Expansion Coefficient of the Graphite-Boron Carbide Composites

Kenji Miyazaki, Kazuo Kobayashi, Hisayoshi Yoshida

1983 Volume 1983 Issue 112 Pages 13-15
Published: January 20, 1983
Released on J-STAGE: June 28, 2010

DOIhttps://doi.org/10.7209/tanso.1983.13

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[title in Japanese]

[in Japanese]

1983 Volume 1983 Issue 112 Pages 16-22
Published: January 20, 1983
Released on J-STAGE: June 28, 2010

DOIhttps://doi.org/10.7209/tanso.1983.16

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[title in Japanese]

[in Japanese], [in Japanese]

1983 Volume 1983 Issue 112 Pages 23-30
Published: January 20, 1983
Released on J-STAGE: June 28, 2010

DOIhttps://doi.org/10.7209/tanso.1983.23

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