Formation of Bulk Alumina Ceramics by Electrophoretic Deposition from Nanoparticle Suspensions

• Published in: Russian Journal of Physical Chemistry A 2021-08, Vol.95 (8), p.1519-1528
• Main Authors: Kalinina, E. G., Rusakova, D. S., Kaigorodov, A. S., Farlenkov, A. S., Safronov, A. P.
• Format: Article
• Language: English
• Subjects: Aluminum base alloys; Aluminum oxide; Bulk density; Ceramics; Challenges in Physical Chemistry; Chemistry; Chemistry and Materials Science; Electrophoretic deposition; Magnesium; Microhardness; Nanoparticles; Physical Chemistry; Problems; Sinterability; Tendencies in Development
• ISSN: 0036-0244; 1531-863X
• DOI: 10.1134/S0036024421080148

High-density ceramics are prepared via electrophoretic deposition (EPD) from suspensions of alumina-based nanopowders. Al 2 O 3 -based nanopowders are obtained through the electrical explosion of wires (EEW) using wire made of an Al–Mg alloy with a magnesium content of 1.3 wt %. Stable nonaqueous suspensions for EPD are prepared using slightly aggregated spherical Al 2 O 3 nanoparticles with a specific surface area of 40 m 2 /g. With EPD and sintering at 1650°С, it is possible to prepare high-density ceramics with a density of 3.93 g/cm 3 (98.6% of the theoretical value) and a microhardness of 17.7 ± 0.5 GPa. Using a nanopowder based on alumina prepared from the Al–Mg alloy contributes to a substantial improvement in the sinterability of ceramics, due to the formation of MgAl 2 O 4 spinel at a content of ≈2.5 wt %, which allows the density and microhardness of ceramic samples to be raised.