Hardfacing materials including PCD particles, earth-boring tools comprising crushed polycrystalline diamond material, and related methods

1. A hardfacing material comprising a metal matrix material and particles of crushed polycrystalline diamond material embedded within the metal matrix material, wherein the particles of crushed polycrystalline diamond material define a substantially continuous open-pore network within the polycrystalline diamond material.

2. The hardfacing material of claim 1 , wherein the particles of crushed polycrystalline diamond material comprise a plurality of inter-bonded diamond grains.

3. The hardfacing material of claim 1 , further comprising additional hard particles, wherein the additional hard particles comprise at least one material selected from the group consisting of carbides, borides, nitrides, and non-polycrystalline diamond.

4. The hardfacing material of claim 3 , wherein the additional hard particles comprise at least one material selected from the group consisting of tungsten carbide, titanium carbide, tantalum carbide, silicon carbide, titanium boride, and silicon nitride.

5. The hardfacing material of claim 1 , wherein the metal matrix material comprises an elongated body.

6. The hardfacing material of claim 5 , wherein the elongated body is generally cylindrical.

7. The hardfacing material of claim 6 , wherein the elongated, generally cylindrical body comprises at least one outer wall, and wherein the particles of crushed polycrystalline diamond material are disposed within the at least one outer wall.

8. The hardfacing material of claim 6 , wherein the elongated, generally cylindrical body comprises a substantially solid cylinder that includes the particles of polycrystalline diamond material embedded within the metal matrix material.

9. A hardfacing material comprising a metal matrix material and particles of crushed polycrystalline diamond material embedded within the metal matrix material, wherein the particles of crushed polycrystalline diamond material are at least substantially planar, have an average particle diameter between about 0.25 millimeter and about 7.0 millimeters, and have an average particle thickness between about 0.1 millimeter and about 5.0 millimeters.

10. An earth-boring tool comprising a body comprising particles of fragmented polycrystalline diamond material embedded within a metal matrix material, the particles of fragmented polycrystalline diamond material comprising a plurality of inter-bonded diamond grains, wherein the particles of fragmented polycrystalline diamond material define a substantially continuous open-pore network within the inter-bonded diamond grains.

11. A method comprising:

forming an earth-boring tool comprising a metal matrix material and particles of crushed polycrystalline diamond material; and

leaching catalyst material from interstitial spaces between the particles of crushed polycrystalline diamond material to form a continuous open-pore network within the crushed polycrystalline diamond material.

12. The method of claim 11 , further comprising breaking a polycrystalline diamond material to form the particles of crushed polycrystalline diamond material.

13. The method of claim 12 , wherein breaking a polycrystalline diamond material to form the particles of the polycrystalline diamond material comprises at least one of crushing, milling, and grinding a layer of polycrystalline diamond material of a cutting element.

14. The method of claim 11 , further comprising forming an elongated, generally cylindrical body comprising the metal matrix material and the particles of crushed polycrystalline diamond material.

15. The method of claim 14 , wherein forming an elongated, generally cylindrical body comprises at least one of a forging process, a casting process, and an extrusion process.

16. The method of claim 14 , wherein forming an elongated, generally cylindrical body comprises:

forming a generally hollow cylindrical tube; and

disposing the particles of crushed polycrystalline diamond material within the hollow cylindrical tube.

17. The method of claim 16 , further comprising sealing at least one end of the elongated, generally cylindrical body.

18. The method of claim 11 , further comprising disposing the particles of crushed polycrystalline diamond material within the metal matrix material.