Gelcasting is a new method for forming advanced ceramics based on obtaining intermediary gels promoted by polimerization “in situ” within the ceramic slurry. Gelcast composites of an ALCOA A-1000 alumina and the copolymer obtained using acrylamide and N,N′-metylene-bisacrylamide as monomers were characterized by thermogravimetry. Polymer distribution was determined by thermogravimetric analysis of small size specimens that were taken from different parts of the alumina composites formed in different shapes. Derivative thermogravimetry was used to identify the resulting polymerization stage within the gelcast body, as well as to study the influence of mold materials and operating conditions. All the composites show an even distribution of the polymer in the bulk, which enables machining in the green state and obtaining high density alumina bodies after sintering.
1 Young, A. C.Omatete, O. O.Janney, M. A.Menchhofer, P. A.1991J. Am. Ceram.Soc.74612–612. .