| abstract |
A super hard polycrystalline construction comprises a body having a first fraction of super hard grains in a matrix of a second fraction of super hard grains, wherein the average grain size of the first fraction is 1.5 to 10 times the average grain size of the second fraction and the first fraction comprises 5 to 30 volume % of the grains of super hard material in the body. The first fraction may comprise one or more of single crystal particles or polycrystalline agglomerates of diamond grit, CVD crushed particles, diamond obtained by PVD methods, natural diamond, synthetic diamond or cubic boron nitride (cBN). The second fraction may comprise diamond grains or cBN grains or both. A method of forming the super hard polycrystalline construction of the invention comprises forming a pre-sinter assembly comprising a first mass and a second mass of particles of super hard materials and a substrate, treating the pre-sinter assembly at a pressure of 5 GPa or greater to form a body of inter-bonded polycrystalline super hard material bonded to the substrate. |