Methods of forming polycrystalline compacts and earth-boring tools including polycrystalline compacts

1. A method of forming a polycrystalline compact, comprising:

polishing at least one surface of a leached portion of a polycrystalline material, from which a catalyst material has been substantially removed by leaching, to form a non-planar surface extending into the leached portion of an at least partially leached polycrystalline compact and having a surface roughness less than about 10 μin. root mean square (RMS), the leached portion of the polycrystalline material comprising inter-bonded grains of hard material having interstitial spaces therebetween that are substantially free of material.

2. The method of claim 1 , wherein the at least partially leached polycrystalline compact comprises an interface between a first volume of polycrystalline material and a second volume of polycrystalline material, the first volume of polycrystalline material having a first concentration of the catalyst material and the second volume of polycrystalline material having a second, substantially higher concentration of the catalyst material, and wherein polishing the at least one surface of the leached portion of the polycrystalline material from which the catalyst material has been substantially removed comprises removing a portion of the first volume of polycrystalline material from the at least partially leached polycrystalline compact.

3. The method of claim 1 , further comprising substantially removing the catalyst material from an additional portion of the polycrystalline material having substantial catalyst material therein after polishing the at least one surface of the leached portion of the polycrystalline material.

4. The method of claim 1 , wherein polishing the at least one surface of the leached portion of the polycrystalline material from which the catalyst material has been substantially removed comprises forming one or more non-planar surfaces in the front cutting face of the at least partially leached polycrystalline compact.

5. The method of claim 1 , wherein polishing the at least one surface of the leached portion of the polycrystalline material from which the catalyst material has been substantially removed comprises forming a recess extending into the leached portion of the polycrystalline material.

6. The method of claim 1 , wherein polishing the at least one surface of the leached portion of the polycrystalline material from which the catalyst material has been substantially removed comprises exposing the polycrystalline material to electromagnetic radiation to remove at least a portion of the leached portion of the polycrystalline material from which the catalyst material has been substantially removed.

7. The method of claim 6 , wherein exposing the polycrystalline material to electromagnetic radiation to remove at least a portion of the leached portion of the polycrystalline material from which the catalyst material has been substantially removed comprises exposing the polycrystalline material to laser irradiation.

8. The method of claim 1 , further comprising forming a chamfer adjacent a front cutting surface of the at least partially leached polycrystalline compact.

9. A method of forming an earth-boring tool, comprising:

forming a polycrystalline cutting element, comprising:

polishing at least one surface of a leached portion of a polycrystalline material, from which a catalyst material has been substantially removed by leaching, to form a non-planar surface extending into a front cutting face of an at least partially leached polycrystalline compact and having a surface roughness less than about 10 μin. root mean square (RMS), the leached portion comprising inter-bonded grains of hard material having interstitial spaces therebetween that are substantially free of material; and

securing the polycrystalline cutting element to a bit body.

10. The method of claim 9 , further comprising substantially removing additional catalyst material in an additional portion of the polycrystalline material having substantial catalyst material therein after polishing the at least one surface of the leached portion of the polycrystalline material from which the catalyst material has been substantially removed and before securing the polycrystalline cutting element to the bit body.

11. The method of claim 9 , wherein forming the polycrystalline cutting element further comprises forming the polycrystalline material on a substrate.

12. The method of claim 9 , wherein polishing the at least one surface of the leached portion of the polycrystalline material from which the catalyst material has been substantially removed comprises forming the front cutting face to comprise one or more non-planar surfaces in the front cutting face of the at least partially leached polycrystalline compact.

13. A method of forming a polycrystalline diamond compact, comprising:

polishing a portion of a first portion of a diamond table from which a catalyst material has been at least partially leached to form a recess extending into the first portion of the diamond table, the first portion of the diamond table comprising inter-bonded grains of hard material having interstitial spaces therebetween that are substantially free of catalyst material;

polishing a front cutting face of the at least partially leached diamond table to form a surface having a surface roughness less than about 10 μin. root mean square (RMS); and

at least partially leaching the catalyst material from a second portion of the diamond table.

14. The method of claim 13 , wherein polishing the portion of the first portion of the diamond table from which the catalyst material has been substantially removed comprises forming one or more recesses extending into the first portion of the diamond table.