Earth-boring rotary drill bits including bit bodies having boron carbide particles in aluminum or aluminum-based alloy matrix materials, and methods for forming such bits
Rotary drill bits for drilling subterranean formations include a bit body and at least one cutting structure disposed on a face thereof. The bit body includes a crown region comprising a particle-matrix composite material that includes a plurality of boron carbide particles dispersed throughout an aluminum or aluminum-based alloy matrix material. In some embodiments, the matrix material may include a continuous solid solution phase and a discontinuous precipitate phase. Methods of manufacturing rotary drill bits for drilling subterranean formations include infiltrating a plurality of boron carbide particles with a molten aluminum or aluminum-based material. In additional methods, a green powder component is provided that includes a plurality of particles each comprising boron carbide and a plurality of particles each comprising aluminum or an aluminum-based alloy material. The green powder component is at least partially sintered to provide a bit body, and a shank is attached to the bit body.
1. A rotary drill bit for drilling subterranean formations, the rotary drill bit comprising:
a bit body including a crown region predominantly comprised of a particle-matrix composite material, the particle-matrix composite material comprising a plurality of boron carbide particles dispersed throughout an aluminum-based alloy matrix material comprising:
at least 75% by weight aluminum;
at least 3.5% by weight copper; and
at least trace amounts of at least one of iron, lithium, magnesium, manganese, nickel, scandium, silicon, tin, zirconium, and zinc; and
at least one cutting structure disposed on a face of the bit body;
wherein the plurality of boron carbide particles comprises between about 40% and about 60% by weight of the particle-matrix composite material, and wherein the aluminum-based alloy matrix material comprises between about 60% and about 40% by weight of the particle-matrix composite material; and wherein the plurality of boron carbide particles includes a multi-modal particle size distribution.
2. The rotary drill bit of claim 1 , wherein the crown region of the bit body comprises a plurality of blades, the at least one cutting structure being disposed on at least one blade of the plurality of blades.
3. The rotary drill bit of claim 1 , wherein the bit body further includes a blank at least partially embedded in the particle-matrix composite material, the blank comprising a metal or metal alloy material and including at least one surface configured for attaching the rotary drill bit to a drill string.
4. The rotary drill bit of claim 1 , wherein the aluminum-based alloy matrix material of the particle-matrix composite material comprises at least 90% by weight aluminum.
5. The rotary drill bit of claim 4 , wherein the aluminum-based alloy matrix material of the particle-matrix composite material comprises a solid solution.
6. The rotary drill bit of claim 5 , wherein the aluminum-based alloy matrix material of the particle-matrix composite material further includes regions comprising at least one precipitate phase dispersed through the solid solution.
7. The rotary drill bit of claim 6 , wherein the at least one precipitate phase comprises a metastable phase.
8. The rotary drill bit of claim 7 , wherein the at least one precipitate phase comprises an intermetallic compound.
9. The rotary drill bit of claim 8 , wherein the intermetallic compound comprises CuAl 2 .
10. The rotary drill bit of claim 1 , wherein the plurality of boron carbide particles comprises a plurality of −20 ASTM Mesh boron carbide particles.
11. The rotary drill bit of claim 1 , wherein the at least one cutting structure comprises a plurality of polycrystalline diamond compact cutters disposed on the face of the bit body.
12. A rotary drill bit for drilling subterranean formations, the rotary drill bit comprising:
a bit body including a crown region predominantly comprised of a particle-matrix composite material, the particle-matrix composite material comprising:
a precipitation-hardened matrix material including at least 75% by weight aluminum and at least 3.5% by weight copper, the precipitation-hardened matrix material comprising:
a continuous phase comprising a solid solution, the solid solution comprising copper solute in aluminum solvent; and
a discontinuous phase comprising a plurality of discrete regions or particles dispersed through the continuous phase, the discontinuous phase comprising a precipitate phase comprising CuAl 2 ; and
a plurality of boron carbide particles dispersed substantially throughout the precipitation-hardened matrix material, the plurality of boron carbide particles including a multi-modal particle size distribution;
wherein the plurality of boron carbide particles comprises between about 40% and about 60% by weight of the particle-matrix composite material, and wherein the precipitation-hardened matrix material comprises between about 60% and about 40% by weight of the particle-matrix composite material; and
at least one cutting structure disposed on a face of the bit body.
13. The rotary drill bit of claim 12 , wherein the crown region of the bit body comprises a plurality of blades, the at least one cutting structure being disposed on at least one blade of the plurality of blades.
14. The rotary drill bit of claim 12 , wherein the bit body further includes a blank at least partially embedded in the particle-matrix composite material, the blank comprising a metal or metal alloy material and including at least one surface configured for attaching the rotary drill bit to a drill string.
15. The rotary drill bit of claim 12 , wherein the precipitation-hardened matrix material of the particle-matrix composite material comprises at least 90% by weight aluminum.
16. The rotary drill bit of claim 12 , wherein the precipitate phase is metastable.
17. The rotary drill bit of claim 12 , wherein the plurality of boron carbide particles comprises a plurality of −20 ASTM Mesh boron carbide particles.
18. The rotary drill bit of claim 12 , wherein the at least one cutting structure comprises a plurality of polycrystalline diamond compact cutters disposed on the face of the bit body.