| 摘要 |
A cutting element comprises a multilayer polycrystalline diamond element 42 bonded to a substrate 44 of a less hard material, the polycrystalline diamond element 42 defining a matrix of interstitial volumes, the interstitial volumes of a first region of the diamond layer 42 adjacent a working surface 46 thereof being substantially free of a catalysing material, the interstitial volumes of a second region of the diamond layer 42 remote from the working surface 46 containing catalysing material. |
