Lowering Crystallization Temperatures by Seeding in Structurally Diphasic Al2O3-MgO Xerogels |
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| Authors: | Yoshiko Suwa Rustum Roy Sridhar Komarneni |
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| Affiliation: | Materials Research Laboratory, The Pennsylvania State University, University Park, Pennsylvania 16802 |
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| Abstract: | Thermal reactions in 93% Al2O3-7% MgO and 95.8% Al2O3-4.2% MgO gels seeded with α-Al2O3, MgAl2O4, α-Fe2O3, and SiO2, sols were investigated by differential thermal analysis to determine the extent of nucleation catalysis of solid-state reactions. Seeding with α-Al2O3 lowered the α-Al2O3 crystallization temperature in these xerogels by 100° to 150°C. Spinel seeds have much less effect on the γ-α transition, and α-Fe2O3 and SiO2 seeds do not affect it significantly. Isostructural seeding of gels may therefore permit lower ceramic processing temperatures. |
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