Abstract
The effect of the residence time at different temperatures on the graphitization of an isotropic baked block was investigated by measuring the changes in structural and physical properties; lattice constant c0, real density, resistivity, hardness and mechanical properties. Samples were heat-treated at different temperatures ranging from 2100 to 3000 °C for residence times from 3 to 960 min. Three different calcined cokes, two derived from pitches with either mosaic or needle-like textures, and one derived from petroleum with a mosaic texture, were also heat-treated and analyzed for comparison. Master curves for properties were obtained on the baked block by a time-temperature superposition rule, and discussed by comparing with those of cokes. The same shift factors to convert between heat-treatment temperature and time could be used to obtain master curves for the structural and physical properties measured, suggesting that the graphitization of these isotropic baked block and calcined cokes proceeds by almost the same process.
