A METHOD OF MAKING A THERMALLY STABLE POLYCRYSTALLINE SUPER HARD CONSTRUCTION

摘要

A method of making a thermally stable polycrystalline super hard construction having a plurality of interbonded super hard grains and interstitial regions disposed therebetween to form a polycrystalline super hard construction having a first thermally stable region and a second region, the first thermally stable region forming at least part of a working surface of the construction, comprises treating the polycrystalline super hard material with a leaching mixture to remove non-super hard phase material from a number of interstitial regions in the first region. The step of treating comprises masking the polycrystalline super hard construction along at least a portion of the peripheral side surface up to and/or at the working surface to inhibit penetration of the leaching mixture into the super hard construction through a peripheral side surface of the super hard construction. The material preferably is PCD, polycrystalline diamond, and preferably leaching takes place after forming a chamfer.