Superhard filler hardmetal including a method of making

• US 6,372,012 B1
• Filed: 07/13/2000
• Issued: 04/16/2002
• Est. Priority Date: 07/13/2000
• Status: Active Grant

• Current Assignee: Kennametal Incorporated
• Original Assignee: Kennametal Incorporated
• Inventors: Eason, Jimmy W., Britzke, Robert W., Majagi, Shivanand
• Primary Examiner(s): MAI, NGOCLAN THI
• Application Number:
  US09/616,112
• Time in Patent Office: 642 Days
• Field of Search: 452/32, 452/36, 452/38, 452/42, 452/43, 419/11, 419/12, 419/13, 419/14, 419/18, 419/19, 419/23, 419/32, 419/35, 419/48
• US Class Current: 75/236
• CPC Class Codes: B22F 2998/00 Supplementary information concerning processes or compositions relating to powder metallurgy
• CPC Class Codes: B22F 3/156 by a pressure medium in liquid or powder form
• CPC Class Codes: C22C 2026/005 with additional metal compounds being borides
• CPC Class Codes: C22C 26/00 Alloys containing diamond or cubic or wurtzitic boron nitride, fullerenes or carbon nanotubes
• CPC Class Codes: C22C 29/00 Alloys based on carbides, oxides, nitrides, borides, or silicides, e.g. cermets, or other metal compounds, e.g. oxynitrides, sulfides C22C26/00 takes precedence

Abstract

A superhard filler hardmetal having a superhard material filler, binder metal or matrix and in some instances at least a first hard component is disclosed. The superhard filler hardmetal has a porosity rating of substantially A06, B00, C00 or better and may be essentially pore free, i.e., A00, B00, C00. The superhard filler hardmetal is formed by mechanically mixing a superhard material, in some instances at least a first hard component and a binder metal or matrix precursor, shaping the mixture into a green body and consolidating the green body at a preselected temperature, superatmospheric pressure and time at temperature and time at superatmospheric pressure sufficient to form the superhard filler hardmetal. The consolidation preferably occurs without the formation of a liquid in the body and at least a portion of the time at superatmospheric pressure is at the preselected temperature. Diamond filler and boron nitride filler are examples of superhard materials usable as filler. The diamond filler may be coated to prevent its degradation during consolidation and use. Boron nitride filler optionally may be coated.

Claims

1. A superhard filler hardmetal comprising:

at least a superhard filler and

a binder metal or matrix comprising at least one of cobalt, nickel, iron, and alloys thereof, the binder metal or matrix embedding the superhard filler; and

the superhard filler hardmetal having a porosity rating of substantially A00, B00 &

C00.

2. A superhard filler hardmetal according to claim 1 further comprising at least one first hard component comprising at least one of carbides, nitrides, borides, oxides, mixtures thereof, solid solutions thereof, and combinations thereof, the binder metal or matrix embedding the at least one first hard component.

3. A superhard filler hardmetal according to claim 1 wherein the superhard filler comprises one or more of single crystal material and polycrystalline material.

4. A superhard filler hardmetal according to claim 1 further comprising a coating on the superhard filler.

5. A superhard filler hardmetal according to claim 4 wherein the superhard filler comprises diamond and the coating comprises at least one of iron, cobalt, nickel, boron, titanium, vanadium, chromium, zirconium, hafnium, tantalum, tungsten, molybdenum, niobium and silicon.

6. A superhard filler hardmetal according to claim 5 wherein the coating comprises a thickness up to about 2.0 μ

m.

7. A superhard filler hardmetal according to claim 1 wherein the superhard filler comprises about 1 vol. % to about 80 vol. %.

8. A superhard filler hardmetal according to claim 2 wherein the superhard filler has a grain size comprising about submicron to about 1500 μ

m.

9. A superhard filler hardmetal according to claim 2 further comprising a second hard phase comprising at least one of carbides, nitrides, borides, oxides, intermetallics, mixtures thereof, solid solutions thereof, and combinations thereof.

10. A superhard filler hardmetal according to claim 4 wherein the coating is different from the binder metal or matrix.

11. A superhard filler hardmetal according to claim 3 wherein the superhard filler comprises about 1 vol. % to about 80 vol. %.

12. A superhard filler hardmetal according to claim 1 comprising at least a portion of a mining tool, a construction tool, and a material removal tool.

13. A superhard filler hardmetal according to claim 1 wherein the superhard filler comprises at least one of diamond, boron nitride and carbon nitride.

14. A superhard filler hardmetal according to claim 5 wherein the diamond filler has a grain size comprising about sub micron to about 1500 μ

m.

15. A superhard filler hardmetal according to claim 2 wherein the binder metal or matrix comprises cobalt and it alloys, the first hard component comprises tungsten carbide, and the coating comprises nickel.

16. A superhard filler hardmetal manufactured by a process comprising the steps of:

forming a mixture by mechanically mixing a superhard filler with a binder metal or matrix precursor;

shaping the mixture into a green body;

consolidating the green body at a preselected temperature, superatmospheric pressure and time at temperature and time at superatmospheric pressure sufficient to form a superhard filler hardmetal, the consolidating occurring without the formation of a liquid in the body and at least a portion of the time at superatmospheric pressure is at the preselected temperature.

17. The superhard filler hardmetal according to claim 16 wherein the said binder metal or said matrix comprising at least one of cobalt, nickel, iron, and alloys thereof, the binder metal or the matrix embedding the superhard filler and at least one hard component.

18. The superhard filler hardmetal according to claim 16 wherein the superatmospheric pressure is applied by rapid omni directional compaction.

19. The superhard filler hardmetal according to claim 16 wherein the time at superatmospheric pressure is less than the time at temperature.

20. The superhard filler hardmetal according to claim 16 wherein the time at superatmospheric pressure is from about 2 seconds to 10 minutes.

21. The superhard filler hardmetal according to claim 16 wherein the time at superatmospheric pressure is from about 2 seconds to about 1 minute.

22. The superhard filler hardmetal according to claim 16 wherein the time at temperature is from about 10 minutes to about 6 hours.

23. The superhard filler hardmetal according to claim 16 wherein the time at temperature is from about 15 minutes to about 1 hour.

24. The superhard filler hardmetal according to claim 16 wherein the mechanical mixing is milling.

25. The superhard filler hardmetal according to claim 16 wherein the superatmospheric pressure is at least about 10,000 pounds per square inch.

26. The superhard filler hardmetal according to claim 25 wherein the superatmospheric pressure is at most about 1,000,000 pounds per square inch.

27. The superhard filler hardmetal according to claim 16 wherein the superatmospheric pressure is at least about 50,000 pounds per square inch.

28. The superhard filler hardmetal according to claim 16 wherein the superatmospheric pressure is at least about 100,000 pounds per square inch.

29. The superhard filler hardmetal according to claim 16 wherein the superatmospheric pressure is at most about6 500,000 pounds per square inch.

30. The superhard filler hardmetal according to claim 16 wherein said porosity rating is in the range of between A00 to A04 and substantially B00.

31. The superhard filler hardmetal according to claim 16 wherein said porosity rating is in the range of between A00 to A02 and substantially B00.

32. The superhard filler hardmetal according to claim 16 wherein said porosity rating is A00 and B00.

33. The superhard filler hardmetal according to claim 30 wherein said hardmental compostion has a porosity rating of C00.

34. The superhard filler hardmetal according to claim 31 wherein said hardmental compostion has a porosity rating of C00.

35. The superhard filler hardmetal according to claim 32 wherein said hardmental compostion has a porosity rating of C00.

36. A superhard filler hardmetal having a porosity rating of substantially A00 manufactured by a process comprising the steps of:

forming a mixture by mechanically mixing a superhard filler with a binder metal or matrix precursor;

shaping the mixture into a green body;

consolidating the green body at a temperature less than 1250 degrees Centigrade, superatmospheric pressure and time at temperature and time at superatmospheric pressure sufficient to form a superhard filler hardmetal.

37. The superhard filler hardmetal according to claim 36 wherein said temperature is between 900 to 1200 degrees Centigrade.

38. The superhard filler hardmetal according to claim 36 wherein said temperature is between 1000 to 1150 degrees Centigrade.

39. The superhard filler hardmetal according to claim 36 wherein said temperature is 1150 degrees Centigrade.

40. A superhard filler hardmetal having a porosity rating of substantially A00 and B00 manufactured by a process comprising the steps of:

forming a mixture by mechanically mixing a superhard filler with a binder metal or matrix precursor;

shaping the mixture into a green body;

consolidating the green body at a temperature less than 1150 degrees Centigrade, superatmospheric pressure and time at temperature and time at superatmospheric pressure sufficient to form a superhard filler hardmetal.