Earth-boring tools for forming wellbores in subterranean earth formations generally include a plurality of cutting elements secured to a body. For example, fixed-cutter earth-boring rotary drill bits (also referred to as “drag bits”) include a plurality of cutting elements fixedly attached to a bit body of the fixed-cutter drill bit. Similarly, roller cone earth-boring rotary drill bits include cones that are mounted on bearing pins extending from legs of a bit body such that each cone is capable of rotating about the bearing pin on which it is mounted. A plurality of cutting elements may be mounted to each cone of such a roller cone drill bit.
The cutting elements used in fixed-cutter, roller cone, and other earth-boring tools often include polycrystalline compact cutting elements, e.g., polycrystalline diamond compact (“PDC”) cutting elements. The polycrystalline compact cutting elements include cutting faces of a polycrystalline compact of a polycrystalline material such as diamond or another super hard material (collectively referred to herein as “super hard material”).
Polycrystalline compact cutting elements may be formed by sintering and bonding together grains or crystals of super hard material in the presence of a metal solvent catalyst. (The terms “grain” and “crystal” are used synonymously and interchangeably herein.) The super hard material grains are sintered and bonded under high temperature and high pressure conditions (referred to herein as “high pressure, high temperature processes” (“HPHT processes”) or “high temperature, high pressure processes” (“HTHP processes”)). The HPHT process forms direct, inter-granular bonds between the grains of super hard material, and the inter-granularly bonded grains form a “table” of the polycrystalline material (e.g., diamond or alternative super hard material). The table may be formed on or later joined to a cutting element supporting substrate.