Chemorheology of alumina-aqueous acrylamide gelcasting systems

Gelcasting is a novel forming method in fabricating complex three-dimensional ceramic parts. A lot of studies have been conducted on the rheological aspects of organic-inorganic suspensions, but up to now few articles have been published on the chemorheological aspects of gelcasting systems. In this work the chemorheology of gelation of aqueous-based alumina-organic monomers suspensions was investigated using stress viscometry techniques. It was concluded from this work that among various variables, such as monomer, crosslinker, initiator and accelerator concentrations, ceramic loading level and temperature, the later parameter has the most significant effect on the idle time and processing time as two critical parameters in the gelcasting of near-net shape articles. The presence of alumina powder has also a catalytic effect. The rheological behaviour of these systems was in good agreement with the original Casson model, too. (C) 2003 Elsevier Ltd. All rights reserved.