Patent ID: 8852304

Claim:
A method for forming a thermally stable diamond bonded compact comprising the steps of: combining together a volume of diamond grains to form a mixture, the mixture being substantially free of a metal solvent catalyst; positioning a reactant material adjacent the mixture at an eventual working surface or mixing reactant material with the mixture in a region forming the eventual working surface; placing a metallic substrate adjacent the mixture opposite the eventual working surface to form an assembly, subjecting the assembly to a first temperature and pressure condition to form a sintered thermally stable diamond bonded region being substantially free of metal solvent catalyst and being remote from the metallic substrate, wherein subjecting the assembly to the first temperature and pressure condition comprises heating the assembly to a temperature less than the melting temperature of the metal solvent catalyst; subjecting the assembly to a second temperature and pressure condition to form a sintered polycrystalline diamond region containing metal solvent catalyst and being adjacent the metallic substrate, and to form an attachment bond between the sintered polycrystalline diamond region and the metallic substrate, thereby forming the thermally stable diamond bonded compact.