Properties of graphite-containing crucibles

Conclusions A study of the thermal conductivity and the electrical resistivity of the specimens of the graphite-containing TGN, TGG, and TKG type crucibles shows that the characteristics of these properties significantly differ depending on the type of the crucibles and the zones in different parts of a given crucible.It is expected that the properties of a given type of crucibles can vary from product to product because of the differences in the compositions and the size fractions of the original raw materials, the postfiring differences in the material, and the structural nonuniformities resulting from compaction.We established the differences in the properties of the graphite-containing crucibles (that depend on the nature of the atmosphere) as a function of temperature.Heating the crucibles in an oxidizing atmosphere leads to partial burning-off (depletion) of their main component (graphite) and to a reduction of the thermal and electrical conductivity of the material of the crucibles.It must be considered that the thermal conductivity of the crucibles working in carbon dioxide atmosphte is 5–10% less than that of the crucibles working in argon atmosphere.Translated from Ogneupory, No. 5, pp. 10–14, May, 1987.