PROCESS FOR PRODUCING ABRASIVE GRAINS BASED ON ALUMINIUM ALPHA-OXIDE

A method of manufacturing abrasive grains based on α-Al2O3 by preparing salt, transforming it to gel, drying, calcination of the xerogel and sintering is based on controlled gelatinisation to set the required microstructures by adding a solution of polybasic organic acids, possibly containing an alloying element, while creating a meta-stable colloidal solution of aluminium hydroxide-oxide in a mix of water and alcohol (1 to 70% of volume) with 1 to 4 carbon atoms with added strong inorganic acids. Subsequently combined capillary desiccation with convection heating on ceramic membranes made of α-Al2O3 or with a fixed layer of α-Al2O3 ensures quick and effective desiccation while simultaneously creating the required structure of xerogel. The xerogel can then be subjected to impregnation with alcohol containing an alloying element. After firing abrasive grains with the required microstructure and potential density of 92 % to 99 % are achieved.