Ds. Horn et Gl. Messing, ANISOTROPIC GRAIN-GROWTH IN TIO2-DOPED ALUMINA, Materials science & engineering. A, Structural materials: properties, microstructure and processing, 195(1-2), 1995, pp. 169-178
Grain growth in TiO2-doped alumina was studied in a high density, ultr
afine matrix (0.4 mu m. Normal grain growth, anisotropic grain growth
and abnormal grain growth were observed. With 0.15-0.4 wt.% TiO2, samp
les initially undergo normal grain growth until a crystal microstructu
re is attained and anisotropic grain growth in nucleated. Large anisot
ropic, platelet-shaped grains grow rapidly by a step growth process un
til impingement of the large grains essentially stops further growth.
The volume fraction of anisotropic grains ranged from 20 to 100 vol.%
suggesting that physical propertis dependent on grain shape and volume
fraction can be tailored. Critical requirements are proposed for the
in situ growth of anisotropic grains.