Texture Development and Microstructure Evolution in Liquid‐Phase‐Sintered α‐Alumina Ceramics Prepared by Templated Grain Growth

Texture development in alumina that contains calcia and silica and has been templated with platelet‐shaped α‐Al 2 O 3 particles has been evaluated. The texture fraction is shown to be related directly to template growth. Texture quality is controlled by the template concentration, decreasing at template concentrations of >10%, as a result of template–template interactions during tape casting. Almost fully textured alumina has been obtained at template concentrations of ≥20%. The growth of template grains is much more rapid in the radial direction and is shown to be inversely related to the thickness of the grain‐boundary liquid. The activation energy for growth (376 kJ/mol) and the inverse relation with the grain‐boundary thickness indicate that template growth in the radial direction is controlled by Al 3+ diffusion.