Fabrication of textured ceramics by colloidal processing in a high magnetic field
National Institute of Material Science (NIMS), Tsukuba, Japan
The controlled development of texture is one of the ways for effectively improving properties of ceramics. 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. Requirements for obtaining textured ceramics by slip casting in a high magnetic field and sintering are as follows: (1) the particle should be single crystal and well dispersed, (2) crystal structure should be non-cubic to yield an anisotropic magnetic susceptibility, (3) magnetic energy should be larger than thermal motion energy, (4) the viscosity of the suspension should be low enough to rotate the particles with a low energy, and (5) grain growth is necessary to obtain a highly oriented structure especially when spherical particles are used. Crystalline-textured controlled laminated composites can be fabricated using EPD by varying the angle between the vectors of electric field and magnetic field. The colloidal processing in a high magnetic field confers several advantages and it is possible for this type of processing to be applied to other non-cubic ceramics, such as alumina, titania, zinc oxide, tin oxide, hydroxyapatite, aluminium nitride, silicon carbide, silicon nitride, etc.
Presentation: Oral at E-MRS Fall Meeting 2008, Symposium I, by Yoshio Sakka
See On-line Journal of E-MRS Fall Meeting 2008
Submitted: 2008-06-03 01:17 Revised: 2009-06-07 00:48