Grain growth in TiO2-doped alumina was studied in a high density, ultrafine matrix (0.4 μm. Normal grain growth, anisotropic grain growth and abnormal grain growth were observed. With 0.15-0.4 wt.% TiO2, samples initially undergo normal grain growth until a crystal microstructure is attained and anisotropic grain growth in nucleated. Large anisotropic, platelet-shaped grains grow rapidly by a step growth process until impingement of the large grains essentially stops further growth. The volume fraction of anisotropic grains ranged from 20 to 100 vol.% suggesting that physical properties dependent on grain shape and volume fraction can be tailored. Critical requirements are proposed for the in situ growth of anisotropic grains.
All Science Journal Classification (ASJC) codes
- General Materials Science
- Condensed Matter Physics
- Mechanics of Materials
- Mechanical Engineering