Patent ID: 6214284
Filing Date: 2001-04-10
Classification: C04B

Abstract:
A process for manufacturing a part based on aluminum nitride comprising the following steps:a) preparing a homogeneous mixture of boron nitride, aluminum and a binder, wherein the binder is in a liquid or paste-like state and capable of solidifying by chemical reaction and/or by solvent loss through drying and wherein the boron nitride and aluminum are in the form of powders;b) forming the mixture by casting in a mold followed by pressing and heating to a temperature not exceeding approximately 70.degree. C. to harden the binder and to obtain a solid and manipulable unfired part;c) eliminating the binder by heating to a temperature of approximately 300.degree. C.;d) impregnating pores of the unfired part by immersion in a bath of aluminum or aluminum alloy in the molten state to form an impregnated preform, removing the impregnated preform from the bath and cooling;e) machining the impregnated preform to form a part having final dimensions;f) reaction sintering the part at a temperature of 900 to 1000.degree. C. to form a ceramic part based on aluminum nitride; andg) heat treating the ceramic part at a temperature of 1100 to 1250.degree. C. to cause residual aluminum to migrate out of pores of the part and after cooling, mechanically eliminating aluminum which has collected on the surface of the part.