par Lucion, Thierry ;Duvigneaud, Paul-Henri ;Laudet, Alain ;Stenger, J.F.;Guegen, E.
Référence Key engineering materials, 264-268, page (209-212)
Publication Publié, 2004
Référence Key engineering materials, 264-268, page (209-212)
Publication Publié, 2004
Article révisé par les pairs
Résumé : | Ti-doped MgO fine powders and MgO-CaO powder mixtures were sintered at temperatures up to 1600°C. TiO 2 was added in the concentration range 0.1 to 2 w%. The promoting effect of TiO 2 is confirmed in all samples having a poor sinterability, i.e. samples with large grain sizes or samples heated at <1500°C. In contrast, complete densification of fine-grained pure magnesia at ≥1500°C is inhibited by TiO 2 amounts ≤ 0.3 w% corresponding to the limit of TiO 2 solubility in MgO. This inhibiting effect can be suppressed in MgO-CaO mixtures with >1.5 w% CaO. The densification of MgO and MgO-CaO mixtures is related to a solid state process wherein cation or anion vacancies diffusion can either be ratedetermining as a function of the sintering stage. |