Cutting structure of cutting elements for downhole cutting tools
A cutting element may include a substrate; and an ultrahard layer on the substrate, the substrate and the ultrahard layer defining a non-planar working surface of the cutting element such that the ultrahard layer forms a cutting portion and the substrate is at least laterally adjacent to the ultrahard layer. Another cutting element includes a pointed region having a side surface extending from the pointed region outer perimeter to a peak. An ultrahard material body forms a portion of the pointed region including the peak, and a base region extends a depth from the pointed region outer perimeter. The ultrahard material body has a height to width aspect ratio with the height and width measured between two points of the body having the greatest distance apart along a dimension parallel with a longitudinal axis (i.e., height) along a dimension perpendicular to the longitudinal axis (i.e., width).
1 . A cutting element, comprising:
a substrate including an upper surface, wherein the upper surface includes an interface surface formed by a groove bisecting the upper surface and extending a length across the upper surface in a convex parabolic shape and through a longitudinal axis of the cutting element;
an ultrahard layer disposed in the groove on the interface surface, the ultrahard layer including a varying width; and
a non-planar working surface including at least a portion of the upper surface of the substrate and at least a portion of the ultrahard layer, wherein the ultrahard layer forms a cutting edge, and wherein a peripheral edge of the non-planar working surface includes at least one substrate edge portion and at least one ultrahard layer edge portion, the at least one substrate edge portion extending away from the cutting edge formed of the ultrahard layer.
2 . The cutting element of claim 1 , wherein the non-planar working surface is axisymmetric.
3 . The cutting element of claim 1 , wherein the ultrahard layer is at least one of a polycrystalline diamond layer or a polycrystalline cubic boron nitride layer.
4 . A cutting element, comprising:
a substrate including a cylindrical side surface and an upper surface, wherein the upper surface includes an interface surface formed by a groove bisecting the upper surface and extending a length across the upper surface in a convex parabolic shape and through a longitudinal axis of the cutting element;
an ultrahard layer disposed in the groove on the interface surface, the ultrahard layer including a varying width; and
a non-planar working surface defined by both the upper surface of the substrate and the ultrahard layer, wherein the ultrahard layer forms a cutting edge, and wherein a peripheral edge of the non-planar working surface between the non-planar working surface and the cylindrical side surface has at least one substrate edge portion and at least one ultrahard layer edge portion, the at least one substrate edge portion extending away from the cutting edge formed of the ultrahard layer.
5 . The cutting element of claim 4 , wherein the non-planar working surface is axisymmetric.
6 . The cutting element of claim 4 , wherein the ultrahard layer is at least one of a polycrystalline diamond layer or a polycrystalline cubic boron nitride layer.