The role of carbon in production of transparent alumina ceramics using powder alcoke technology

The poor reproducibility of the transparency of corundum ceramics obtained by alkoxy technology is associated with the possibility of oxidized carbon from alkoxy groups entering the solid solution with Al ₂ O ₃ . Carbon suppresses the effect of magnesium oxide addition, enhances diffusion mass transfer, pore entrapment by growing crystals, and polymorphic transition to corundum. The introduction of carbon in the form of soot or naphthalene during dry grinding into a pre-decarburized powder g-Al ₂ O ₃ , its subsequent heat treatment in air or in an environment of humid CO _{2 < / sub> and sintering the samples in vacuum confirmed this assumption. Tab. 1, ill. 2, bibliography. 14 titles}