Super hard constructions & methods of making same

Abstract

A super hard construction ( 1 ) comprises a substrate ( 30 ) and a super hard material layer ( 32 ) formed over the substrate. One of the interface surface ( 38 ) of the substrate or the interface surface of the super hard material layer comprises a plurality of spaced-apart projections ( 44, 46 ); the projections ( 44 ) being arranged in an annular discontinuous first array around the central longitudinal axis and spaced from the peripheral surface ( 40 ) of the substrate by a distance of between around 1 mm to around 1.5 mm A second annular discontinuous array of projections ( 46 ) is positioned radially within the first array. The projections in the second array are positioned to radially align with spaces between the projections in the first array, the interface surface between the projections being substantially planar; and the projections in the first array are of a greater height than the projections in the second array.

1 . A super hard construction comprising:
 a substrate comprising a peripheral surface, an interface surface and a longitudinal axis; and   a super 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 super hard material layer comprises:
 a plurality of spaced-apart projections arranged to project from the interface surface; 
   the projections being arranged in a substantially annular discontinuous first array around the central longitudinal axis and spaced from the peripheral surface of the substrate by a distance of between around 1 mm to around 1.5 mm and a second substantially annular discontinuous array of projections radially within the first array;
 the projections in the second array being positioned to radially align with spaces between the projections in the first array; 
 the interface surface between the projections being substantially planar; and 
   wherein the projections in the first array are of a greater height than the projections in the second array.   
     
     
         2 . The super hard construction of  claim 1 , wherein the first and second arrays are substantially concentric with the substrate. 
     
     
         3 . The super hard construction of  claim 1 , wherein the first array comprises substantially the same number of projections as the second array. 
     
     
         4 . The super hard construction of  claim 1 , wherein the projections in the first and second arrays are staggered relative to each other. 
     
     
         5 . The super hard 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 super 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. 
     
     
         6 . The super hard construction of  claim 1 , wherein the thickness of the super hard material layer about the central longitudinal axis of the substrate is substantially the same as the thickness of the super hard material layer at the peripheral surface. 
     
     
         7 . The super hard construction of  claim 1 , wherein the super hard material layer comprises polycrystalline diamond. 
     
     
         8 . The super hard construction of  claim 1 , wherein the exposed outer surface of the super hard layer is substantially planar. 
     
     
         9 . The super hard construction of  claim 1 , wherein the interface surface of the substrate is a negative or reversal of the interface surface of the super hard material layer such that the two interface surfaces form a matching fit. 
     
     
         10 . The super hard construction of  claim 1 , wherein the super hard construction is a cutter element. 
     
     
         11 . The super hard construction of  claim 1 , wherein the projections are arranged such that there is reflective symmetry along a plane though the central axis. 
     
     
         12 . An earth boring drill bit comprising a body having the super hard construction of  claim 1  mounted thereon as a cutter element. 
     
     
         13 . A method of forming the super hard construction of  claim 1 . 
     
     
         14 . (canceled)