Gelcasting of Alumina

Abstract

Gelcasting is a novel method for molding ceramic powder based on a synthesis of concepts derived from traditional ceramics and polymer chemistry. Gelcasting of alumina is described in this paper. The process is based on the in situ polymerization of acrylamide monomers as the setting mechanism for forming the green body. It has the following features: slurries with high solids loading and low viscosity (1.8 Pa-s at 62 vol% solids), dried bodies containing less than 4 wt% binder, and the ability to fabricate complexshaped bodies. [

Processing of cellular ceramics by foaming and in situ polymerisation of organic monomers

“…Commonly applied types in ceramic systems include methyl methacrylate, butyl acrylate [14], acrylamide [15], and other acrylates [17]. The polymerisation of these vinyl monomers can be brought about by a variety of initiating systems that have a marked influence on the rates at which the reaction proceeds.…”

“…The routes and substances currently used for the setting of fluid suspensions, regardless of whether they have been previously foamed, can be classified as follows: drying or freeze-drying of the solvent [10], compositions which can form a gel intrinsically [11], the incorporation of gelling substances such as cellulose derivatives [12] or alginates [13], and the in situ polymerisation of monomers [14][15][16][17][18].…”

Thermal decomposition of monosaccharides derivatives applied in ceramic gelcasting process investigated by the coupled DTA/TG/MS analysis

“…There are many shaping techniques in ceramic technology but most of them have important disadvantages such as nonhomogeneity of powder compacts, size and geometry limit of produced element, use of high pressure, long binder burnout and high costs. In order to overcome these limitations some novel shaping technologies have been recently developed on the basis of colloidal processing of ceramic powders, for example gelcasting [1][2][3], monomer based sol-gel, electrophoretic deposition [4,5] or direct coagulation casting [6,7]. Gelcasting allows obtaining high-quality, complex-shaped ceramic elements by means of an in situ polymerization, through which a macromolecular network is created to hold ceramic particles together (Fig.…”

Development and mechanical characterization of novel ceramic foams fabricated by gel-casting

“…To overcome the drawbacks of these preparation methods, and to satisfy the criteria of homogeneity, reproducibility, reliability and processability required for complex shape commercial ceramics, processing by gelcasting has been developed [3]. Gelcasting is a near-net-shape forming method that combines slip processing with polymer chemistry.…”