Methods of forming earth-boring tools using inserts and molds

1. A method of forming a body of an earth-boring downhole tool, comprising:

additively manufacturing at least one blade insert comprising an insert body formed of particles of hard-phase material and a binder material, with:

a thickness varying along at least one dimension chosen from among a length, a width and a height; and

at least one opening formed in and extending through the insert body, the at least one opening sized for a portion of a respective PDC cutting element on a bit body of the earth-boring downhole tool to extend therethrough;

positioning the at least one blade insert within a mold cavity of a mold, the mold cavity defining a shape corresponding to the shape of the body of the earth-boring downhole tool to be formed therein with:

outer surfaces of the at least one blade insert arranged to form an outer surface and at least portions of rotationally leading and rotationally trailing surfaces of at least one blade of the body of the earth-boring downhole tool;

providing additional particles of hard-phase material within the mold cavity;

infiltrating the additional particles of hard-phase material with molten metal, and sintering and/or infiltrating the at least one blade insert to form the body of the earth-boring downhole tool comprising a corresponding cutting element pocket formed by the at least one opening of the at least one blade insert and the bit body; and

securing the respective PDC cutting element to the bit body within the corresponding cutting element pocket.

2. The method of claim 1 , wherein positioning at least one blade insert within a mold cavity of a mold comprises positioning a three-dimensionally (3D) printed at least one blade insert within the mold cavity.

3. The method of claim 1 , further comprising selecting the at least one blade insert to include fibers in the binder material of the at least one blade insert.

4. The method of claim 1 , further comprising selecting the at least one blade insert to include an aqueous binder material.

5. The method of claim 1 , further comprising attaching the at least one blade insert within the mold cavity using an adhesive.

6. The method of claim 1 , further comprising selecting the particles of hard-phase material to comprise at least one of: particles of tungsten carbide, diamond particles, and particles of a hydrophobic ceramic.

7. The method of claim 6 , further comprising selecting the particles of hard-phase material to comprise spherical tungsten carbide particles.

8. The method of claim 1 , further comprising selecting the particles of hard-phase material to comprise a mixture of particles of a first hard-phase material and particles of a different second hard-phase material.

9. The method of claim 1 , further comprising selecting the particles of hard-phase material to have a multi-modal grain size distribution.

10. The method of claim 1 , further comprising selecting the particles of hard-phase material to have a mesh size of between 40 ASTM mesh and 635 ASTM mesh.

11. The method of claim 1 , further comprising forming the at least one blade insert to further comprise particles of metal matrix material.

12. The method of claim 11 , further comprising selecting the particles of metal matrix material to comprise a copper-based alloy.

13. The method of claim 1 , further comprising forming a non-planar interface between the at least one blade insert and the bit body of the earth-boring downhole tool to provide increased bond strength between the at least one blade insert and the bit body of the earth-boring downhole tool.

14. The method of claim 1 , further comprising forming a portion of an outer surface of the at least one blade insert to have a geometry conforming to a geometry of a portion of at least one interior surface of the mold defining the mold cavity within the mold, and wherein positioning the at least one blade insert within the mold cavity comprises positioning the portion of the outer surface of the at least one blade insert adjacent the portion of the at least one interior surface of the mold.

15. The method of claim 1 , further comprising providing a bonding material comprising nickel or a nickel-based alloy on at least a portion of an exterior surface of the at least one blade insert.

16. The method of claim 1 , further comprising selecting the particles of hard-phase material of the at least one blade insert to have a different composition and/or a different average particle size relative to additional particles of hard-phase material provided within the mold cavity.

17. The method of claim 1 , wherein, after formation of the body of the earth-boring downhole tool, the at least one blade insert exhibits dimensions within five-millimeters of intended design dimensions for the at least one blade insert in the body of the earth-boring downhole tool.

18. The method of claim 1 , wherein positioning at least one blade insert comprises using one or more alignment features, selected from among ridges, ribs, waveforms, bubbles, honeycombs, and lattices, arranged on at least a portion of the at least one blade insert to align the at least one blade insert within the mold cavity.

19. The method of claim 1 , further comprising selecting the at least one blade insert to comprise a hydrophobic material.