Texture development and microstructure evolution in liquid-phase-sintered alpha-alumina ceramics prepared by templated grain growth

Texture development in alumina that contains calcia and silica and has been templated with platelet-shaped alpha -Al2O3 particles has been evaluated. The texture fraction is shown to be related directly to template growth. Te xture quality is controlled by the template concentration, decreasing at te mplate concentrations of >10%, as a result of template-template interaction s during tape casting. Almost fully textured alumina has been obtained at t emplate concentrations of greater than or equal to 20%. The growth of templ ate grains is much more rapid in the radial direction and is shown to be in versely related to the thickness of the grain-boundary liquid. The activati on energy for growth (376 KJ/mol) and the inverse relation with the grain-b oundary thickness indicate that template growth in the radial direction is controlled by Al3+ diffusion.