Tape Cast Porous Nano Alumina Multilayer Composites

Abstract

Alumina tapes are extensively utilized as useful components for device applications and fabrication of multilayer composites for structural applications. The tapes are mostly fabricated from a stable dispersion of micron size alumina powder in a non-aqueous medium for industrial purpose. Here we report the novel development of a tailored tape cast light weight, porous nano alumina multilayer composite, suitable for structural applications. A 150 nm particle size alumina powder with 99.97% purity was used. For tape casting, oxidized Menhaden fish oil (MFO) was used as dispersant and an azeotropic mixture of methyl ethyl ketone (MEK) and ethanol (EtOH) as solvent. The viscosity value of the nano alumina/solvent/dispersant slurry system was found out to be the minimum at about 8 wt% dispersant concentration. Sintered porous nano alumina tapes with 55% relative density were prepared at 1400°C in air from the suitably optimized tape casting slurry composition obtained from the aforesaid optimization experiments. Using similar green tapes and sintering temperature, tailored porous nano alumina/nano alumina tape cast multilayer composites (MLC) with 63-70% relative densities were fabricated. These novel, porous nano alumina/nano alumina multilayer composite (NA/NA MLC) materials exhibit high failure energy (74 KJ.m⁻³) that is about 20 times that of porous nano alumina tape (3.5 KJ.3⁻³).

Keywords:

• Nano alumina
• Multilayer
• Composite
• Failure energy
• Porous