Modeling anisotropic single crystal growth kinetics in liquid phase sintered α-Al2O3

Single crystals of alpha-alumina with {0001}, {11 (2) over bar 0} and {01 (1) over bar 2} orientations were embedded in a matrix of liquid phase sintered alumina to study alpha-alumina single crystal growth in the presence of a calcium aluminosilicate liquid. Growth on the {11 (2) over bar 0} and {01 (1) over bar 2} surfaces was observed to occur by a diffusion-controlled mechanism while growth on the basal surface was controlled by two-dimensional nucleation. Growth models, which incorporate the change in matrix grain size, were derived and shown to fit the growth kinetics.