摘要 |
A cutting element includes a multilayer polycrystalline diamond element bonded to a substrate of a less hard material. The polycrystalline diamond element defines a matrix of interstitial volumes. The interstitial volumes of a first region of the diamond layer are adjacent a working surface thereof being substantially free of a catalyzing material. The interstitial volumes of a second region of the diamond layer are remote from the working surface containing the catalyzing material. |