Porous abrasive tool and method for making the same

• US 6,685,755 B2
• Filed: 11/21/2001
• Issued: 02/03/2004
• Est. Priority Date: 11/21/2001
• Status: Expired due to Term

• Current Assignee: Saint-Gobain Abrasives Incorporated (Compagnie De Saint-Gobain)
• Original Assignee: Saint-Gobain Abrasives Technology Company
• Inventors: Buljan, Sergej-Tomislav, Ramanath, Srinivasan, Wilson, Jason R., Ikeda, Jeri Ann S.
• Primary Examiner(s): MARCHESCHI, MICHAEL A
• Application Number:
  US09/990,647
• Publication Number:
  US 20030097800A1
• Time in Patent Office: 804 Days
• Field of Search: 512/96, 513/07, 513/08, 513/09, 512/93, 512/98, 513/02
• US Class Current: 51/296
• CPC Class Codes: B24D 3/10 for porous or cellular structure, e.g. for use with diamonds as abrasives
• CPC Class Codes: B24D 99/005 Segments of abrasive wheels
• CPC Class Codes: C09K 3/1409 Abrasive particles per se preparation of diamond C01B32/25

Abstract

An abrasive article including from about 40 to about 80 volume percent interconnected porosity, the article being useful as a segment for a segmented grinding wheel, and a method for fabricating the same. The method includes blending a mixture of abrasive grain, bond material and dispersoid particles, the mixture including from about 40 to about 80 volume percent dispersoid particles. In one embodiment the mixture includes from about 50 to about 80 volume percent dispersoid particles. In another embodiment the mixture includes an organic bond material and from about 40 to about 80 volume percent dispersoid particles. The powder mixture is then pressed into an abrasive laden composite and thermally processed. After cooling the composite is immersed into a solvent, which dissolves substantially all of the dispersoid particles, leaving a highly porous, bonded abrasive article.

Claims

1. A method for fabricating an abrasive article having at least 50 volume percent. interconnected porosity, said method comprising:

a) blending a mixture of abrasive grain, bond material, and dispersoid particles, said mixture including from about 0.5 to about 25 volume percent abrasive grain, from about 19.5 to about 49.5 volume percent bond material, and from about 50 to about 80 volume percent dispersoid particles;

b) pressing said mixture into an abrasive laden composite;

c) thermally processing the composite; and

d) immersing said composite into a solvent for a period of time suitable to dissolve substantially all of said dispersoid, said dispersoid being soluble in said solvent;

said abrasive grain and said bond material being substantially insoluble in said solvent.

2. The method of claim 1 wherein said pressing (b) and said thermally processing (c) are performed substantially simultaneously.

3. The method of claim 2 wherein the mixture is pressed for at least five minutes at a temperature ranging from about 370 to about 795°

C. at pressures ranging from about 20 to about 33 megaPascal.

4. The method of claim 1 wherein the volume percent of dispersoid particles in said mixture ranges from:

greater than or equal to about 50 volume percent; and

less than or equal to about 70 volume percent.

5. The method of claim 1 wherein said bond material is a metal bond.

6. The method of claim 5 wherein said metal bond comprises from about 35 to about 85 weight percent copper and from about 15 to about 65 weight percent tin.

7. The method of claim 5 wherein said metal bond further comprises from about 0.2 to about 1.0 weight percent phosphorus.

8. The method of claim 1 wherein said bond material is organic bond.

9. The method of claim 8 wherein said organic bond comprises a phenolic resin.

10. The method of claim 1 wherein said abrasive grain comprises a superabrasive grain selected from the group consisting of diamond and cubic boron nitride.

11. The method of claim 1 wherein said abrasive grain comprises diamond.

12. The method of claim 1 wherein said abrasive grain comprises an average particle size ranging from:

greater than or equal to about 0.5 microns; and

less than or equal to about 300 microns.

13. The method of claim 1 wherein said abrasive grain comprises an average particle size ranging from:

greater than or equal to about 5 microns; and

less than or equal to about 75 microns.

14. The method of claim 1 wherein said dispersoid is a water soluble salt.

15. The method of claim 1 wherein said dispersoid is member of the group consisting of sugar, dextrin, polysaccharide oligomers, sodium chloride, potassium chloride, magnesium chloride, calcium chloride, sodium silicate, sodium metasilicate, potassium phosphate, potassium silicate, sodium carbonate, sodium sulfate, potassium sulfate, magnesium sulfate, and mixtures thereof.

16. The method of claim 1 wherein said dispersoid comprises sodium chloride.

17. The method of claim 1 wherein said dispersoid comprises sugar.

18. The method of claim 1 wherein said dispersoid has a particle size ranging from:

greater than or equal to about 25 microns; and

less than or equal to about 500 microns.

19. The method of claim 1 wherein said dispersoid has a particle size distribution ranging from:

greater than or equal to about 74 microns; and

less than or equal to about 210 microns.

20. The method of claim 1 wherein said dispersoid has a particle size distribution ranging from:

greater than or equal to about 210 microns; and

less than or equal to about 300 microns.

21. The method of claim 1 wherein said dispersoid comprises sugar and has a particle size distribution ranging from:

greater than or equal to about 150 microns; and

less than or equal to about 500 microns.

22. The method of claim 1 wherein said solvent comprises water.

23. The method of claim 1 wherein said solvent comprises boiling water.

24. The method of claim 1 wherein at least one surface of the composite is abraded after said thermal processing (c) and prior to said immersing (d).

25. The method of claim 1 for producing an abrasive article having a permeability of greater than or equal to about 0.2 cubic centimeter per second per inch of water.

26. An abrasive article fabricated by the method of claim 1.

27. A method for fabricating an abrasive article having from about 40 to about 80 volume percent interconnected porosity, said method comprising:

a) blending a mixture of abrasive grain, non-metallic bond material, and dispersoid particles, said mixture including from about 0.5 to about 25 volume percent abrasive grain, from about 19.5 to about 65 volume percent non-metallic bond material, and from about 40 to about 80 volume percent dispersoid particles;

b) pressing said mixture into an abrasive laden composite;

c) thermally processing the composite; and

d) immersing the composite into a solvent for a period of time suitable to dissolve substantially all of the dispersoid, the dispersoid being soluble in the solvent;

the abrasive grain and the non-metallic bond material being substantially insoluble in the solvent.

28. The method of claim 27 wherein the non-metallic bond material comprises an organic bond material.

29. The method of claim 28 wherein the organic bond material comprises a resin selected from the group consisting of phenolic resins, epoxy resins, unsaturated polyester resins, bismaleimide resins, polyimide resins, cyanate resins, melamine polymers, and mixtures thereof.

30. The method of claim 28 wherein the organic bond material comprises a phenolic resin.

31. The method claim 28 wherein the organic bond material comprises a phenolic novolac resin.

32. The method of claim 28 wherein the organic bond material comprises a phenolic resole resin.

33. The method of claim 28 wherein said abrasive grain comprises diamond having an average particle size ranging from:

greater than or equal to about 0.5 microns; and

less than or equal to about 300 microns.

34. The method of claim 28 wherein the dispersoid particles are substantially non-ionic.

35. The method of claim 28 wherein the dispersoid particles comprise sugar.

36. The method of claim 28 wherein said pressing (b) comprises pressing for at least five minutes at a temperature ranging from about 100 to about 200°

C. at pressures ranging from about 20 to about 33 megaPascal.

37. The method of claim 28 wherein said thermal processing (c) is performed after said immersing (d) and comprises baking for at least one hour at a temperature ranging from about 100 to about 200°

C.

38. The method of claim 28 wherein at least one surface of the composite is abraded prior to said immersing (d).