Patent ID: 8309050

Claim:
A method for making a diamond construction comprising the steps of: subjecting a volume of diamond grains to a high pressure/high temperature condition in the presence of a catalyst material to form a fully sintered polycrystalline diamond body having a diamond content of at least 93 percent by volume; and treating at least a first region of the diamond body extending from a working surface to render the region substantially free of the catalyst material while allowing the catalyst material to remain in an untreated region; wherein the first region extends within the polycrystalline diamond material only to a depth of from 0.01 mm to 0.08 mm as measured from the working surface, wherein the diamond grains comprise a multimodal distribution of differently-sized diamond grains, and wherein a majority by volume of the total diamond grains have an average particle size of 0.05 mm to 0.1 mm.