All issues
Volume 1983 (1983)
- Issue 115 Pages 155-
- Issue 114 Pages 97-
- Issue 113 Pages 47-
- Issue 112 Pages 2-
Volume 1983, Issue 114
Displaying 1-7 of 7 articles from this issue
- |<
- <
- 1
- >
- >|
-
Naotaka Ekinaga1983 Volume 1983 Issue 114 Pages 97-102
Published: July 01, 1983
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSThe fracture toughness tests of commercial artificial graphite electrodes were carried out, where crack initiation and its subsequent extension were monitored by electrical potential method.Since all of the specimens fractured nonlinearly, the fracture toughness of these graphite specimens was evaluated by J-integral procedure.J-value of these materials increased nonlinearly with the increase in the crack extension Δα.It was concluded that the J-value can be expressed by the nonlinear regression equation of J=Ji+S (Δα) m.For the artificial graphite electrodes studied, Ji and S increased with the increase in bending strength.Whereas the exponent m is constant (=0.6) irrespective of the used graphite materials.View full abstractDownload PDF (738K) -
S. Yoda, T. Oku, Y. Kougo1983 Volume 1983 Issue 114 Pages 103-109
Published: July 01, 1983
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSChanges in Young's modulus, electrical resistivity, and bending strength of IG-11 graphite in the directions parallel to and perpendicular to compressive prestress were measured.From the results, a model for compressive deformation of polycrystalline graphite was proposed.
The electrical resistivity in the direction parallel to the loading axis decreased with increase in compressive prestress up to 0.4 σf, where σf denotes the average compressive strength, 80 MPa, of the graphite.Then it increased abruptly with increasing the prestress to above 0.4 σf, whereas that in the direction perpendicular to the loading axis increased over the whole prestress level.Young's modulus in the direction parallel to the loading axis was unchanged with increase in the prestress up to 0.4 σf and it decreased abruptly above 0.4 σf, whereas that in the direction perpendicular to the axis decreased with increase in the prestress up to 0.4 σf and decreased slightly above 0.4 σf.Bending strength in the direction parallel to the loading axis increased with increase in the prestress up to 0.4 σf and decreased above 0.4 σf, whereas the strength in the two directions perpendicular to the loading axis unchanged up to 0.2 σf thereafter those decreased abruptly.
A model was proposed for compressive deformation mechanism of polycrystalline graphite: In the case of low compressive stress pore and/or microcracks on the basal plane perpendicular to the loading axis in the grain would be shrunk or closed.On the basal plane parallel to the loading axis formation of microcracks would occur because of plastic flow in the direction perpendicular to the loading axis.On removal of compressive stress tensile stress is expected to be generated on account of release of elastic strain around the grains which are deformed plastically in the loading direction.The tensile stress naturally produces many cleavage microcracks on the basal plane perpendicular to loading axis.This model is supported by mercury porosimetry which showed micropores with around 1μm diam. increased with increase in the prestress.View full abstractDownload PDF (990K) -
Takeshi Meguro, Naochika Torikai1983 Volume 1983 Issue 114 Pages 110-119
Published: July 01, 1983
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSThis is a proposal of new method for kinetics study on the reaction of artificial graphites with carbon dioxide.
In order to investigate the gasification of artificial graphites, the reaction rates were measured in a batchwise reactor connected with circulation system.Five artificial graphite samples were used in this experiments, i.e., PGX (UCC), ATJ (UCC), H-451 (GLCC), IG-11 (A), (B) (TOYO TANSO).These samples were allowed to react with carbon dioxide at 1000°C. The initial gas composition in a system was carbon dioxide only or carbon dioxide and nitrogen mixture.During the reaction, carbon monoxide increased progressively and total volume increased.However, the pressure in the reactor was maintained at atmospheric pressure with the aid of a variable Tedlar bag fitted with the circulation system.Oxygen partial pressure Po2 in the system was measured by means of a oxygen concentration cell (stabilized ZrO2) heated at 950°C, so that Pco2 /Pco ratio was determined.On the basis of Boudouard reaction, the rates of reaction expressed as burn-off per unit time were calculated from the ratio Pco2 /Pco and initial amount of carbon dioxide, and sample weight.Results obtained in this study were seen to obey the Langmuir-Hinshelwood equation.View full abstractDownload PDF (10736K) -
Y. Takada, R. Fujii, K. Matsuo1983 Volume 1983 Issue 114 Pages 120-123
Published: July 01, 1983
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSDownload PDF (455K) -
Michio Inagaki, Yosuke Shiwachi1983 Volume 1983 Issue 114 Pages 124-125
Published: July 01, 1983
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSDownload PDF (254K) -
H. Jüntgen1983 Volume 1983 Issue 114 Pages 126-137
Published: July 01, 1983
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSDownload PDF (1588K) -
K.J. Hüttinger, W. Huettner1983 Volume 1983 Issue 114 Pages 138-149
Published: July 01, 1983
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSDownload PDF (7906K)
- |<
- <
- 1
- >
- >|