Fabrication and some properties of textured alumina-related compounds by colloidal processing in high-magnetic field and sintering

Recently to improve properties, highly microstructure controlled ceramics such as fine-grained, textured and laminated structures are required. We have demonstrated a new processing of textured ceramics with a feeble magnetic susceptibility by colloidal processing in a high-magnetic field and subsequent heating. As colloidal processing, slip casting and electrophoretic deposition (EPD) have been conducted successfully. Colloidal processing is known to be a powerful method for consolidating fine particles with a high density and homogeneous microstructure. Crystalline-textured controlled laminated alumina can be fabricated using EPD by varying the angle between the vectors of electric field and magnetic field. Also textured ceramics with complicated structure such as P-alumina and alumina-based nanocomposite can be fabricated by reaction sintering. The textured alumina-related compounds showed anisotropic properties depending on the crystal plane. The colloidal processing in a high-magnetic field confers several advantages and can be applied to many non-cubic ceramics. (c) 2007 Elsevier Ltd. All rights reserved.