FIELD: technological processes.
SUBSTANCE: invention relates to polishing composition used for polishing an object to be polished, consisting of hard and brittle material, having Vickers hardness equal to 1,500 Hv or higher. Invention also relates to a method of polishing hard and brittle material and a method of producing a substrate consisting of such material. Composition contains at least abrasive grains of aluminium oxide and water and has pH value equal to 8.5 or more. Abrasive grains of aluminium oxide have specific surface area equal to 20 m2/g or less.
EFFECT: enabling production of substrate, film, et cetera, from hard and brittle materials, such as sapphire, silicon nitride and silicon carbide, containing a smaller amount of surface defects and having excellent smoothness of surface with high efficiency of polishing.
8 cl, 4 tbl, 8 ex
