Freeze casting for Al2O3 was accomplished at room temperature with nonaqueous sublimable vehicles in the naphthalene-camphor eutectic system with a eutectic temperature of 31 deg C. A fully dense sintered body was obtained with a eutectic composition vehicle, whereas at most 90% T.D. was obtained with an off-eutectic composition vehicle due to formation of large uniquely shaped voids. Microstructural observation suggested that growing pro-eutectic crystals rejected the suspended Al2O3 particles to form large voids during the solidification process. At the eutectic composition, formation of fine lamellar microstructure in a solidified vehicle is considered to inhibit particle rejection resulting in large voids.
Origin
University Of Michigan, Usa
Journal Title
Jacs 87 11 2004 2014-2019
Sector
Glass Ceramics
Class
GC 612