Superhard constructions and methods of making same

Abstract

A superhard construction comprises a substrate and an ultra hard material layer formed over the substrate. One of the interface surface of the substrate or the interface surface of the ultra hard material layer comprises a plurality of spaced-apart projections arranged to project from the interface surface, the interface surface between the spaced-apart projections being uneven. A further superhard construction comprises a plurality of projections arranged to project from the interface surface which abut one or more adjacent projections along an edge thereof on the surface from which the projections project, and extend over all or a majority of the interface surface. One or more of the surfaces of all or a majority of the projections extend in one or more planes which are not substantially parallel to the plane of the exposed outer surface of the ultra hard material layer and/or in one or more planes which are not substantially parallel to a plane through which the central longitudinal axis of the substrate extends.

1 . A superhard construction comprising:
 a substrate comprising a periphery and an interface surface and a longitudinal axis; and   an ultra hard material layer formed over the substrate and having an exposed outer surface, a peripheral surface extending therefrom and an interface surface; wherein one of the interface surface of the substrate or the interface surface of the ultra hard material layer comprises:   a plurality of spaced-apart projections arranged to project from the interface surface, the interface surface between the spaced-apart projections being uneven.   
     
     
         2 . The superhard construction of  claim 1 , wherein all or a majority of the interface surface between the spaced-apart projections is non-curved and extends in one or more planes which are not substantially parallel to the plane of the exposed outer surface of the ultra hard material layer. 
     
     
         3 . The superhard construction of  claim 1 , the substrate having a central longitudinal axis, wherein all or a majority of the interface surface between the spaced-apart projections extends in one or more planes which are not substantially parallel to a plane through which the central longitudinal axis of the substrate extends. 
     
     
         4 . The superhard construction of  claim 1 , wherein the projections are arranged in one or more substantially radial arrays around the central longitudinal axis of the substrate. 
     
     
         5 . The superhard construction of  claim 4 , wherein the projections are arranged in a first array and a second array, the second array being positioned radially within the first array. 
     
     
         6 . The superhard construction of  claim 5 , wherein the first and second arrays are substantially concentric with the substrate. 
     
     
         7 . The superhard construction of  claim 5 , wherein the first array comprises substantially double the number of projections than the second array. 
     
     
         8 . The superhard construction of  claim 5 , wherein the projections in the first and second arrays are staggered relative to each other. 
     
     
         9 . The superhard construction of  claim 1 , wherein the projections are randomly arranged on one of the interface surface of the substrate or the interface surface of the ultra hard material layer. 
     
     
         10 . The superhard construction of  claim 1 , wherein one or more of the surfaces of all or a majority of the projections extend in one or more planes which are not substantially parallel to the plane of the exposed outer surface of the ultra hard material layer and/or in one or more planes which are not substantially parallel to a plane through which the central longitudinal axis of the substrate extends. 
     
     
         11 . The superhard construction of  claim 1 , wherein the thickness of the ultra hard material layer about the central longitudinal axis of the substrate is substantially the same as the thickness of the ultra hard material layer at the peripheral surface. 
     
     
         12 . The superhard construction of  claim 1 , wherein the ultra hard material layer comprises polycrystalline diamond. 
     
     
         13 . The superhard construction of  claim 1 , wherein the exposed outer surface of the ultra hard layer is substantially planar. 
     
     
         14 . (canceled) 
     
     
         15 . The superhard construction of  claim 5 , wherein the projections in the first array are of a greater height than the projections in the second array. 
     
     
         16 . A superhard construction comprising:
 a substrate comprising a periphery and an interface surface and a longitudinal axis; and   an ultra hard material layer formed over the substrate and having an exposed outer surface, a peripheral surface extending therefrom and an interface surface; wherein one of the interface surface of the substrate or the interface surface of the ultra hard material layer comprises:   a plurality of projections arranged to project from the interface surface, the projections abutting one or more adjacent projections along an edge thereof on the surface from which the projections project, and extending over all or a majority of the interface surface; and   wherein one or more of the surfaces of all or a majority of the projections extend in one or more planes which are not substantially parallel to the plane of the exposed outer surface of the ultra hard material layer and/or in one or more planes which are not substantially parallel to a plane through which the central longitudinal axis of the substrate extends.   
     
     
         17 . The superhard construction of  claim 16 , wherein any interface surface between any projections or not covered by the projections is uneven. 
     
     
         18 . The superhard construction of  claim 16 , wherein the projections are substantially pyramidal. 
     
     
         19 . The superhard construction of  claim 16 , wherein the projections are arranged in an ordered array over the interface surface. 
     
     
         20 . The superhard construction of  claim 1 , wherein the interface surface of the substrate is a negative or reversal of the interface surface of the ultra hard material layer such that the two interface surfaces form a matching fit. 
     
     
         21 . The superhard construction of  claim 1 , wherein the superhard construction is a cutter element. 
     
     
         22 - 23 . (canceled)