A method for the production of beta'-sialon based ceramic powders.

摘要

Disclosed is a method to obtain beta min -sialon-based ceramic powders through carbo-thermal reduction in a nitrogen atmosphere at 13OO-15OO DEG C of pre-mullitic material with high specific surface and reactivity; the latter material having a crystalline phase with a formula of 3Al2O3, 2SiO2 and a proportion of displaced amorphous silica, and the overall proportion of Al2O3/SiO2 ranges from O.5 to 1.5 giving specific surfaces that are always higher than 5O m<2>/g. The product obtained has a major phase of beta min -sialon with a formula of Si6-zAlzN8-zOz (where z=2.7-4.O) and small proportions or traces of other phases such as alpha -Al2O3, beta -Si3N4 and polytypes.