Drill bits and other articles of manufacture including a layer-manufactured shell integrally secured to a cast structure and methods of fabricating same

Abstract

A rotary-type earth-boring drill bit including a layer-manufactured, substantially hollow bit crown and an integral bit interior and bit gage. The bit interior and bit gage may be formed of a particulate material infiltrated with an infiltrant material. A particulate material of the bit crown may be integrally infiltrated with the particulate material of the bit interior and bit gage. Alternatively, the bit interior and bit gage may comprise a single cast material. The particulate material of the bit crown may be infiltrated with the cast material of the bit interior and bit gage. A method of fabricating the drill bit includes employing known layered-manufacturing techniques to fabricate the bit crown, positioning a bit gage mold adjacent the bit crown, and disposing a core material within an interior of the bit crown and a cavity of the bit gage mold. A mold that may be employed to fabricate the drill bit includes an initially conforming mold region, in which the pre-fabricated bit crown may be disposed, and a second, substantially rigid mold region including a cavity to define the gage of the drill bit. Preferably, the conforming mold region is formed of a non-wettable, granular material.

Dependencies are inferred from the claim text.