Cemented carbide inserts for earth-boring bits

Abstract From the Canadian patent

This invention relates to cutting inserts for earth boring bits comprising a cutting zone wherein the cutting zone comprises first cemented hard particles and a body zone wherein the body zone comprises second cemented hard particles. The first cemented hard particles may differ in at least one property from the second cemented hard particles. As used herein the cemented hard particles means a material comprising hard particles in a binder. The hard particles may be at least one of a carbide a nitride, a boride, a silicide, an oxide and solid solutions thereof and the binder may be at least one metal selected from cobalt nickel, iron and alloys of cobalt, nickel or iron.