Alumina ceramics based on seeded boehmite and electrophoretic deposition

It is shown that seeding a commercial boehmite sol with crystallographically suitable seeds reduces both the crystallization temperature for the final α-A12O3 phase and the sintering densification temperature. The seeding component was a tailored combination of δ- and α-alumina particles in nanometre and micrometer ranges, respectively, dispersed in water. Electrophoretic deposition (EPD) provided a quick, simple and cost-effective processing route to prepare dense monolithic alumina ceramics from the seeded boehmite suspensions. EPD-formed green bodies could be sintered and densified at temperatures as low as 1250 °C for 2 h.