Texture development in reaction-bonded alumina (RBAO) ceramics via templated grain growth

Texture development in liquid-phase sintered RBAO ceramics has been studied during templated grain growth (TGG): a technique for developing crystallographic texture in ceramic bodies via the grain growth of aligned non-equiaxed particles in a dense and fine grain size matrix. The process of TGG occurs in 3 stages: densification, initial growth of individual template particles and template impingement and template thickening. To understand texture development in RBAO ceramics during each stage of TGG, we have performed a series of experiments to isolate the growth of an individual grain. Experiments with samples containing low template (approx. 1 vol%) concentration at 1450°C showed that the radial growth of platelets is rapid and controlled by diffusion, whereas growth perpendicular to the basal surface is controlled by nucleation.