Dual-Edge Working Surfaces for Polycrystalline Diamond Cutting Elements

Abstract

A PCD cutting element, which in operation (and as it wears to a worn condition) presents at least two cutting lips to the material being cut. One particularly advantageous use of this new PDC cutting element is as cutting elements for earth boring drill bits.

Description

BACKGROUND OF THE INVENTION [0001] 1. Field of the Invention [0002] The invention relates to superhard polycrystalline material elements for earth drilling, cutting, and other applications where engineered superhard surfaces are needed. The invention particularly relates to polycrystalline diamond and polycrystalline diamond-like (collectively called PCD) elements with dual edged working surfaces. [0003] 2. Description of the Related Art [0004] Polycrystalline diamond and polycrystalline diamond-like elements are known, for the purposes of this specification, as PCD elements. PCD elements are formed from carbon based materials with exceptionally short inter-atomic distances between neighboring atoms. One type of diamond-like material similar to PCD is known as carbonitride (CN) described in U.S. Pat. No. 5,776,615. In general, PCD elements are formed from a mix of materials processed under high-temperature and high-pressure into a polycrystalline matrix of inter-bonded superhard car...

AI Technical Summary

Benefits of technology

[0019] The invention also relates to a method of manufacturing a cutting element comprising forming a table of superhard material bonded to a less hard substrate, the table of superhard material defining a plurality of interstices containing a catalyzing material, the table defining an end working surface and a peripheral working surfa

Problems solved by technology

A common trait of PCD elements is the use of catalyzing materials during their formation, the residue from which, often imposes a limit upon the maximum useful operating temperature of the element while in service.

The assembly is then subjected to very high temperature and pressure in a press.

Such an element may be subject to thermal degradation due to differential thermal expansion between the interstitial cobalt binder-catalyzing material and diamond matrix beginning at temperatures of about 400 degrees C. Upon sufficient expansion the diamond-to-diamond bonding may be ruptured and cracks and chips may occur.

A common problem with these PCD elements, especially when used in highly abrasive cutting application, such as in drill bits, has been the limitation imposed between wear resistance and impact strength.

In observing these PCD cutting elements in the worn condition, it was discovered that the differential wear rate caused a protruding lip to form on the wear edge of the working surface.

Images