Low Cost Production of Transparent Spinel Domes Using Freeze Casting

This Phase I SBIR ARMY project proposes the development of 7” in diameter hemispherical spinel domes (3.5” radius, 0.18” wall thickness, 160 degree aperture) through the combination of freeze casting (FC) technology with unique nanopowder technology commercialized by MER for magnesium aluminate spinel (MgAl2O4) ceramics. These technologies allow for the production of spinel domes with high green density, green near net shape, no residual stress, that result in less distortion in the final sintered dome. The novel process requires less secondary machining after sintering to produce high quality transparent domes at a lower cost when compared to cold isostatic pressing (CIP) technology.