Graded drilling cutters
View Patent ↗In an embodiment, an abrasive compact includes ultra-hard particles which are sintered, bonded, or otherwise consolidated into a solid body. The compact also includes various physical characteristics having a continuous gradient, a multiaxial gradient, or multiple independent gradients.
1. A method of creating an abrasive compact, comprising:
combining ultra-hard particles with a fluid to create a mixed slurry;
allowing the mixed slurry to separate and form a graded layer;
removing remaining liquid from the graded layer;
selecting a portion of the graded layer;
placing a substrate against the selected portion of the graded layer to create an initial assembly;
processing the initial assembly to produce a sintered abrasive compact supported on the substrate to form a recovered assembly.
2. The method of claim 1 where further comprising the step of finishing the supported sintered compact into an abrasive tool.
3. The method of claim 1 , wherein the allowing comprises allowing the mixed slurry to settle in a non-planar fixture; and wherein the placing comprises placing an interface surface of the substrate so that the interface surface matches a surface of the graded layer.
4. The method of claim 1 , wherein the placing comprises orienting the graded layer and the substrate so that a surface of the substrate having more coarse particles is near the substrate.
5. The method of claim 1 , wherein said compact comprises a plurality of superabrasive particles consolidated into a solid mass, the particles having a characteristic gradient that is continuous, monotonic and uniaxial.
6. The method of claim 5 , wherein the characteristic gradient comprises a particle size gradient.
7. The method of claim 5 , wherein a maximum rate of change of particle size is less than 1 micron of particle size per 1 micron of translation.
8. The method of claim 5 , wherein the characteristic gradient comprises a pore size gradient.
9. The method of claim 8 , in which a maximum rate of change of pore size is less than 1 micron of diameter per 1 micron of translation.
10. The method of claim 5 , wherein the characteristic gradient comprises a particle shape gradient.
11. The method of claim 6 , in which a maximum rate of change of particle aspect ratio is less than 0.1 per 1 micron of translation.
12. The method of claim 5 , wherein the characteristic gradient comprises a concentration of the superabrasive particles.
13. The method of claim 1 , wherein the abrasive compact comprises a plurality of superabrasive particles consolidated into a solid mass, the mass having a first continuous gradient along a first axis of the mass and a second continuous gradient along a second axis of the mass.
14. The method of claim 13 , wherein each of the gradients comprises a particle size gradient.
15. The method of claim 9 , wherein the first continuous gradient comprises a particle size gradient and a second continuous gradient comprises one of a pore size gradient, a particle shape gradient, or a superabrasive particle concentration gradient.
16. The method of claim 15 , wherein the first continuous gradient is monotonic and uniaxial.
17. The method of claim 15 , wherein the first continuous gradient is oscillating.