巻号一覧
1984 巻 (1984)
- 119 号 p. 181-
- 118 号 p. 117-
- 117 号 p. 61-
- 116 号 p. 2-
1984 巻, 117 号
選択された号の論文の7件中1～7を表示しています
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高温における表面状態と組成の変化堀江 典郎1984 年 1984 巻 117 号 p. 61-67
発行日: 1984/04/25
公開日: 2010/06/28
ジャーナル フリーProperties, surface condition and composition of the carbon foams containing fillers such as the powder of glass and titanium white are investigated.These carbon foams were prepared by the heat-treatment of the phenol resin foam containing filler at heat treatment temperature of1500, 2000, 2500°C for30minutes under an atmosphere of Argon. Further, using the foam heat-treated at2900°C, the influence of the filler on graphitization is examined.
The scanning electron microscope (SEM) is used for the observation on the condition of surface of the carbon foams, further the spectroscope attached to SEM and X-ray diffractometer are used for the investigation of the composition of them.
The pores of the foam get out of shape as the heat treatment temperature are increased.
Bulk density of the foam increases with the elevation of the heat treatment temperature and the increase of the filler contents.
Condition of the distribution of the silicon in glass and titanium in titanium white is almost equal to all over the foam.So, the reason of increase of the compressive strength of the carbon foam is not reinforcement of the cell wall of the foam but the thickening of it.
Titanium and silicon carbonize at considerably lower temperature than that at which the usual carbide-cristalls are formed.
At the heat treatment temperature 2900°C, the graphitization of the carbonized phenol resin foam without filler is bad, therefore, multiple graphitization is shown in this case. But that of the carbon foam containing glass and titanium white are remarkably improved.抄録全体を表示PDF形式でダウンロード (12877K) -
宮崎 憲治, 小林 和夫1984 年 1984 巻 117 号 p. 68-73
発行日: 1984/04/25
公開日: 2010/06/28
ジャーナル フリーBending strength from room temperature to 2500°C was measured for three kinds of boron-doped polycrystalline graphites which were prepared from calcined pitch coke by hotpressing at 2200°C under a pressure of19.6MPa (200kg/cm2) or39.2MPa (400kg/cm2) with a sintering aid, boron trioxide or boron carbide.Temperature dependence of their strength was compared with that for some conventional graphite samples.
Strength of boron-doped samples increased with increasing temperature up to 2000°C and began to decrease at about 2000°C. However, some of them recovered their strength above about 2300°C.On the other hand, the conventional graphite samples showed monotonous increase in strength up to 2500°C.Though plastic deformation was observed in all samples above 2000°C, the plasticity seemed to be much more pronounced in the boron-doped hot-pressed samples.
It was considered that the strength of boron-doped hot-pressed samples above 2000°C was closely related to the diffusion of boron into coke grains and the melt of residual boron carbide among the grains.抄録全体を表示PDF形式でダウンロード (2607K) -
高 尚愚, 山辺 潔, 高橋 浩, 斉藤 泰和1984 年 1984 巻 117 号 p. 74-80
発行日: 1984/04/25
公開日: 2010/06/28
ジャーナル フリーPore structures and surface chemical species of the three kinds of commercial activated carbons derived from different starting materials and activation methods have been determined by means of nitrogen adsorption isotherms (77K) and thermo-gravimetric/mass spectrometric analysis.
The carbon specimen, activated with zinc chloride, exhibited larger specific surface area and pore volume as well as wider pore size distribution than those of the other two kinds of carbons, activated with gas.
Formation of surface oxygenated species was dependent on both starting materials and activation methods. Degree of carbonization was particularly smaller for the zinc chloride activation than for the gas activation. Surface active sites occupied less than 6% of the total surface areas of the gas activated carbons, which indicate that the surface of these carbons is mostly hydrophobic.
In conclusion, the pore structures and the surface chemical species of the commercial activated carbons were highly influenced by the starting materials as well as the activation methods.抄録全体を表示PDF形式でダウンロード (869K) -
斎藤 保, 松尾 秀人, 今井 久1984 年 1984 巻 117 号 p. 81-85
発行日: 1984/04/25
公開日: 2010/06/28
ジャーナル フリーA nuclear grade graphite, H327, was deformed by the application of 22.6 MPa compressive stress at temperatures of 20, 800, 1000 and 1200°C.Plastic deformation became larger with the stressing temperature, and the bulk density increase was mainly due to the longitudinal residual strain which was caused by the rupture and deformation of pores.
The deformation within graphite crystallites was not detected by conventional X-ray method, however, appreciable increase in crystallographic anisotropy was observed for samples stressed at above 1000°C.Moreover, these anisotropy changes were not recovered by the heat-treatments up to 2000°C.These results suggest that large local distortions must occur at the crystallite boundaries and some of these strains might be accommodated by the increase in crystallite preferred orientation.抄録全体を表示PDF形式でダウンロード (664K) -
山田 能生, 白石 稔, 古田 毅, 山下 安正, 山川 敏雄1984 年 1984 巻 117 号 p. 86-93
発行日: 1984/04/25
公開日: 2010/06/28
ジャーナル フリーCarbonization behavior of several hydrogenated acenaphthylene pitches was studied by means of a polarized light microscope.The pitches before the hydrogenation were prepared by heat-treating acenaphthylene at 430°C for 2, 4, 8 and 24 h.In the case of the pitch treated at 430°C for 4 h, pyridine insolubles alone were used for the hydrogenation.Thus they have different amounts of quinoline insolubles or anisotropic textures.But the hydrogenation using BenKeser reduction completely converted the heat-treated pitches optically isotropic.Thisresult can be interpreted as follows: the reduction weakened the interaction between the molecules in the lamellae because of the formation of partially hydrogenated aromatic compounds.Consequently, the arrangement of the lamellae is considered to be destroyed.
When the pitches hydrogenated were carbonized again at the temperature range from 400 to 430°C, they showed different manners of the appearance and the growth of the anisotropic textures, depending on the amount of quinoline insolubles in the pitch before the hydrogenation.Particularly, the pitch heat-treated at 430°C for 24 h, which contains 96.8% of quinoline insolubles exhibited an isotropic texture by the hydrogenation and again gave an enlarged-flow domain without formation of mesophase spheres by treating at 430°Cfor 1 h.These observations are explained in terms of the difference in fluidity which is caused mainly by the degree of carbonization before the hydrogenation.
In conclusion, the development of the anisotropic textures can be controlled to some extent by pretreatment and the following hydrogenation of pitch.抄録全体を表示PDF形式でダウンロード (13791K) -
中溝 実, 玉井 桂子1984 年 1984 巻 117 号 p. 94-97
発行日: 1984/04/25
公開日: 2010/06/28
ジャーナル フリーPDF形式でダウンロード (558K) -
東原 秀和, 角野 広平, 渡辺 信淳1984 年 1984 巻 117 号 p. 98-111
発行日: 1984/04/25
公開日: 2010/06/28
ジャーナル フリーPDF形式でダウンロード (8247K)
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