A study on alumina product characteristics - density and shrinkage, by gel-casting process

Abstract

The gel-casting process involves the in situ polymerisation of acrylamide monomers, serving as the setting mechanism for the formation of a green body. Successful fabrication of high green strength gel-cast components has been achieved with varying solid loading percentages, specifically 45%, 50%, and 55% by volume. It has been noted that a gradual increase in solid loading results in a decrease in shrinkage values and the formation of a denser structure. Gel-cast components of different shapes and sizes have been successfully sintered. The final cast product fabricated with 55 volume% slurry is having a relative sinter density 98% and a linear drying shrinkage of 4.5%. The alumina product is observed to be formed under rhombohedral crystal symmetry, and the presence of Al-O vibration bonds is identified by FTIR results. At the higher temperature, intense heat sintered the ceramic, resulting in a hard and dense final product.