Patent ID: 6346689
Filing Date: 2002-02-12
Classification: B01J,B32B,C04B

Abstract:
A composite hard material article, including:a body having a variable microstructure said microstructure being represented in an outer surface and an interior core, the body being formed from composite hard material including hard particles; the body having a surface layer at the outer surface which has a higher hard particle content than the interior core thus forming a more closely packed hard particle network in the surface layer than in the interior core of the body; and the body being formed from a single substantially homogenous mixture of the composite hard material, and application of a temperature and pressure cycle to the mixture which densifies the mixture firstly by compaction of the surface layer and then compaction inwardly to the centre of the mixture with the establishment of a pressure gradient within the mixture to produce comparatively lower compaction towards the centre of the mixture so as to form the body, having the outer surface with the higher hard particle content than the interior core, from the single substantially homogenous mixture of the composite hard material.