Milling apparatus for a paved surface

1. An apparatus for directional degradation of a surface, comprising:

an attachment assembly connected to a motorized vehicle comprising at least one degradation tool;

the at least one degradation tool comprising a substantially cylindrical rotary degradation element having a substantially cylindrical working surface formed about a rotational axis;

a plurality of cutting inserts embedded within the substantially cylindrical working surface and adapted to degrade a surface in a direction substantially normal to the rotational axis;

at least one of the plurality of cutting inserts comprising a superhard material bonded to a cemented metal carbide substrate at a non-planar interface;

the superhard material comprising a substantially pointed geometry with an apex comprising a 0.050 to 0.160 inch radius and a 0.100 to 0.500 inch thickness from the apex to the non-planar interface; and

at least two degradation tools being adapted for independent movement relative to the attachment assembly.

2. The apparatus of claim 1 , wherein the superhard material comprises a 0.125 to 0.300 inch thickness from the apex to the non-planar interface.

3. The apparatus of claim 1 , wherein the superhard material and the substrate comprise a total thickness of 0.200 to 0.700 inches from the apex to a base of the substrate.

4. The apparatus of claim 3 , wherein the substrate comprises a maximum height from the base to the non-planar interface that is less than one-half of the total thickness from the apex to the base.

5. The insert of claim 1 , wherein the superhard material comprises a substantially conical surface having a side which forms a 35 to 55 degree angle with a central axis of the insert.

6. The apparatus of claim 5 , wherein the angle is substantially 45 degrees.

7. The apparatus of claim 1 , wherein the substantially pointed geometry comprises a convex side.

8. The apparatus of claim 1 , wherein the substantially pointed geometry comprises a concave side.

9. The apparatus of claim 1 , wherein the substrate comprises a tapered surface at the interface starting from a cylindrical rim of the substrate and ending at an elevated flatted central region formed in the substrate.

10. The apparatus of claim 9 , wherein the flatted region comprises a diameter of 0.125 to 0.250 inches.

11. The apparatus of claim 1 , wherein the superhard material is diamond, polycrystalline diamond, natural diamond, synthetic diamond, vapor deposited diamond, silicon bonded diamond, cobalt bonded diamond, thermally stable diamond, polycrystalline diamond with a binder concentration of 1 to 40 weight percent, infiltrated diamond, layered diamond, monolithic diamond, polished diamond, course diamond, fine diamond, cubic boron nitride, diamond impregnated matrix, diamond impregnated carbide, metal catalyzed diamond, or combinations thereof.

12. The apparatus of claim 1 , wherein each of the plurality of inserts comprises a substrate diameter and each insert is within a distance equal to its own substrate diameter to at least one other insert.

13. The apparatus of claim 1 , wherein a volume of the superhard material is 75 to 150 percent of a volume of the carbide substrate.

14. The apparatus of claim 1 , wherein the insert is brazed or press fit to the degradation element.

15. The apparatus of claim 1 , wherein the substrate is attached to blades formed on the outer surface of the cylindrical rotary degradation element.

16. The apparatus of claim 1 , wherein the working surface is adapted to angularly contact the surface to be degraded at a negative rake angle.

17. The apparatus of claim 16 , wherein the negative rake angle is from 0.1° to 60°.

18. The apparatus of claim 1 , wherein the rotary degradation element is attached to the vehicle by a shaft substantially coaxial with a central axis of the degradation element.

19. The apparatus of claim 1 , wherein the rotary degradation element is in communication with an actuating mechanism adapted to move the rotary degradation element in an horizontal, vertical, transverse, diagonal and pivotal direction relative to the motorized vehicle.