Patent ID: 6395214
Filing Date: 2002-05-28
Classification: C04B

Abstract:
A method for fabricating a nanocrystalline ceramic article, the method comprising the steps of:synthesizing loosely-agglomerated ceramic nanopowder having a metastable structure; forming the ceramic nanopowder into a compact; and sintering the ceramic nanopowder compact under a pressure of 3 GPa to 5.5 GPa and at a temperature no greater than about 0.6 times the melting temperature of the ceramic nanopowder to form the nanocrystalline article, in which said metastable structure transforms into a stable structure with a smaller specific volume or a significant reduction in free volume of said metastable structure occurs, wherein a grain size of the nanocrystalline ceramic article is a nanoscale grain size which is smaller than a particle size of the ceramic nanopowder formed in the synthesizing step.