METHOD FOR PREPARING STRUCTURAL CERAMIC NANOCOMPOSITES OF ALUMINA AND SILICON CARBIDE, AND NANOCOMPOSITES PREPARED BY THE METHOD

摘要

Alumina/silicon carbide structural ceramic nanocomposites having a high erosive wear resistance are prepared by a method which, in addition to the conventional steps of mixing alumina and silicon carbide, drying the mixture, and consolidating it by pressureless sintering optionally preceded by cold isostatic pressing to fabricate a compact, is characterised by the incorporation, at the mixing stage, of a sintering dopant selected from the oxides of yttrium, magnesium, titanium, calcium, zinc, zirconium, cerium and the other lanthanides except promethium, and mixtures of said oxides. The method lowers the temperature necessary for sintering, for a given sintering dwell time, significantly below conventional values. The proportion of dopant is 0.1 % to 5 % by weight of the composite.