Sintered bodies for earth-boring rotary drill bits and methods of forming the same

Abstract

The present invention relates to compositions and methods for forming a bit body for an earth-boring bit. The bit body may comprise hard particles, wherein the hard particles comprise at least one carbide, nitride, boride, and oxide and solid solutions thereof, and a binder binding together the hard particles. The binder may comprise at least one metal selected from cobalt, nickel, and iron, and, optionally, at least one melting point reducing constituent selected from a transition metal carbide in the range of 30 to 60 weight percent, boron up to 10 weight percent, silicon up to 20 weight percent, chromium up to 20 weight percent, and manganese up to 25 weight percent, wherein the weight percentages are based on the total weight of the binder. In addition, the hard particles may comprise at least one of (i) cast carbide (WC+W2C) particles, (ii) transition metal carbide particles selected from the carbides of titanium, chromium, vanadium, zirconium, hafnium, tantalum, molybdenum, niobium, and tungsten, and (iii) sintered cemented carbide particles.

1 . A method for forming an earth-boring rotary drill bit, the method comprising forming a bit body, comprising: 
 providing a powder mixture including a plurality of particles and a binder material;    pressing the powder mixture to form a green powder component;    sintering the green powder component to a final density; and    attaching a shank to the sintered bit body using at least one of a pin, a keyway, an adhesive, a brazing process, and a diffusion bonding process.