A superhard cutter having grains with a specified mean free path

摘要

A superhard polycrystalline construction includes a body of polycrystalline superhard material formed of a mass of superhard grains exhibiting inter-granular bonding and defining a plurality of interstitial regions therebetween, the superhard grains having an associated mean free path; and a non-superhard phase at least partially filling a plurality of the interstitial regions and having an associated mean free path. The average grain size of the superhard grains is less than or equal to 25 microns; and the ratio of the standard deviation in the mean free path associated with the non-superhard phase to the mean of the mean free path associated with the non-superhard phase is greater than or equal to 80% when measured using image analysis techniques at a magnification of 1000.