High-hardness abrasive product based on alumina and aluminium oxycarbides and process for preparing same
AssigneeSociete Francaise d'Electrometallurgie Sofrem
InventorsMarc Daire, Yves Larrere, Andre Mangin
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Abstract
The invention relates to a new class of high-hardness abrasive products and wear resistant parts based on alumina and aluminium oxycarbides. By fusing alumina in the presence of a carbonaceous substance and by controlled cooling, it is possible to obtain a large number of products in which the ratio .rho. of the number of carbon atoms to the number of carbon atoms plus oxygen atoms is between 0.01 and 0.50, and preferably between 0.02 and 0.20. These products are essentially constituted by primary alumina crystals in a eutectic matrix Al.sub.2 O.sub.3 - Al.sub.4 O.sub.4 C or Al.sub.2 O.sub.3 - Al.sub.2 OC.
Claims16
A high-hardness abrasive product, characterised in that it is constituted by the combination of crystalline phases of alumina and of at least one of the two aluminium oxycarbides Al.sub.2 OC and Al.sub.4 O.sub.4 C, in which the ratio .rho. of the number of carbon atoms to the number of carbon atoms plus oxygen atoms (C/C+O) is between 0.01 and 0.50.
A process for the preparation of high-hardness abrasive products comprising the steps of fusing alumina in the presence of a carbonaceous substance to derive a reaction product constituted by alumina and at least one of the two aluminum oxycarbides Al.sub.2 OC and Al.sub.4 O.sub.4 C in which the ratio .rho. of the number of carbon atoms to the number of carbon atoms plus oxygen atoms (C/C+O) is between 0.01 and 0.50 and cooling the the reaction product to a solid at a controlled, predetermined rate.
Dependencies are inferred from the claim text.