Claims
- 1. An abrasive tool having a modulus of rupture of at least 6,000 psi, comprising at least 1%, by volume, MCA abrasive grain and 3 to 30%, by volume, of a vitrified bond, wherein the vitrified bond, during firing of the abrasive tool at about 700 to 1,100° C., comprises at least two immiscible phases.
- 2. The abrasive tool of claim 1, wherein the vitrified bond is prepared from bond components comprising a glass frit.
- 3. The abrasive tool of claim 1, wherein the immiscible phases of the vitrified bond during firing of the abrasive tool are amorphous phases.
- 4. The abrasive tool of claim 1, wherein the vitrified bond comprises a major amount of an alkaliborosilicate glass.
- 5. The abrasive tool of claim 4, wherein at least one of the immiscible phases of the vitrified bond during firing of the abrasive tool comprises 1 to 8 mole % P2O5.
- 6. The abrasive tool of claim 4, wherein the vitrified bond comprises a minimum of 8 mole % B2O3, and less than 12 mole % Al2O3.
- 7. The abrasive tool of claim 1, wherein the tool comprises 4 to 25 volume % vitrified bond and 10 to 56 volume % MCA abrasive grain.
- 8. The abrasive tool of claim 7, wherein the tool further comprises about 0.1 to 60 volume % of additional components selected from the group consisting of secondary abrasive grains, fillers and adjuncts.
- 9. The abrasive tool of claim 7, wherein the MCA abrasive grain is selected from the group consisting essentially of alpha-alumina microcrystalline grain manufactured by a seeded sol-gel process, alpha-alumina microcrystalline grain manufactured by an unseeded sol-gel process, modifications thereof with rare earth metal oxides, and combinations thereof.
- 10. The abrasive tool of claim 4, wherein the vitrified bond comprises a molar ratio of B2O3 to alkali oxides of 5.25:1 to 1:1.
- 11. The abrasive tool of claim 4, wherein the alkali oxides are selected from the group consisting of Na2O, Li2O, and K2O and combinations thereof.
- 12. The abrasive tool of claim 4, wherein the vitrified bond after firing further comprises a maximum of 2 mole % of a component selected from the group consisting of fluorine containing components, ZnO, ZrO2, CaO, MgO and combinations thereof.
- 13. An abrasive tool comprising at least 1%, by volume, MCA abrasive grain and 3 to 30%, by volume; vitrified bond, wherein the vitrified bond comprises after firing of the abrasive tool, 40 to 60% SiO2, 10 to 18% Al2O3, 12 to 25% alkali oxides, 5 to 20% B2O3 and 1 to 8% P2O5, on a mole percent basis, and whereby the abrasive tool is characterized by at least a 30% increase in modulus of rupture relative to an comparable abrasive tool made with a vitrified bond comprising less than 1 mole at P2O5.
- 14. The abrasive tool of claim 10, wherein the alkali oxides are selected from the group consisting of Na2O, Li2O, and K2O and combinations thereof.
- 15. The abrasive tool of claim 13, wherein the vitrified bond is fired at 700-1,100° C.
- 16. The abrasive tool of claim 13, wherein the tool comprises 4 to 25 volume % vitrified bond and 10 to 56 volume % MCA abrasive grain.
- 17. The abrasive tool of claim 16, wherein the tool further comprises about 0.1 to about 60 volume % of additional components selected from the group consisting of secondary abrasive grains, fillers and adjuncts.
- 18. The abrasive tool of claim 10, wherein the MCA abrasive grain is selected from the group consisting essentially of alpha-alumina microcrystalline grain manufactured by a seeded sol-gel process, alpha-alumina microcrystalline grain manufactured by an unseeded sol-gel process, modifications thereof with rare earth metal oxides, and combinations thereof.
- 19. The abrasive tool of claim 10, wherein the vitrified bond after firing further comprises a maximum of 2 mole % of at least one oxide selected from the group consisting of TiO2, ZnO, ZrO2, CaO, MgO, CoO, MnO2, BaO, Bi2O3 and Fe2O3, and combinations thereof.
- 20. The abrasive tool of claim 19, wherein the vitrified bond after firing comprises alkaline earth oxides and the molar ratio of SiO2 to the combined contents of alkali oxides and alkaline earth oxides is at least 1.5:1.0.
- 21. A method for making an abrasive tool having a modulus of rupture of at least 6,000 psi, comprising the steps of:a) mixing about 70 to 95 weight % abrasive grain selected from the group consisting of MCA grain, silicon carbide grain, diamond grain, and cubic boron nitride grain, and mixtures thereof, and about 5 to 30 weight % bond mixture, the bond mixture comprising, after firing of the abrasive tool, 40 to 60% SiO2, 10 to 18% Al2O3, 12 to 25% alkali oxides, 5 to 20% B2O3, and 1 to 8% P2O5, on a mole percent basis; b) molding the mixture into a green composite; and c) firing the green composite at a temperature in the range of 700 to 1,100° C. to form the abrasive tool; and whereby the abrasive tool is characterized by at least a 30% increase in modulus of rupture relative to an comparable abrasive tool made with a vitrified bond comprising less than 1 mole % P2O5.
- 22. The method of claim 21, wherein the green composite is fired at a temperature less than about 950° C.
- 23. The method of claim 21, wherein the abrasive tool is selected from the group consisting of grinding wheels, abrasive stones and abrasive hones.
- 24. The method of claim 21, wherein the firing step is carried out in an oxidizing atmosphere.
- 25. The method of claim 23, wherein the abrasive tool is a microabrasive superfinishing tool.
- 26. The abrasive tool of claim 4, wherein the vitrified bond comprises alkali oxides in a ratio of 1:1:1 to 2:1:1 of sodium:lithium:potassium.
- 27. The abrasive tool of claim 13, wherein the vitrified bond comprises alkali oxides in a ratio of 1:1:1 to 2:1:1 of sodium:lithium:potassium.
Parent Case Info
This application is a 371 of PCT/US01/09347, filed Mar. 23, 2001 which claims priority of U.S. provisional application No. 60/191,607, filed Mar. 23, 2000.
PCT Information
Filing Document |
Filing Date |
Country |
Kind |
PCT/US01/09347 |
|
WO |
00 |
Publishing Document |
Publishing Date |
Country |
Kind |
WO01/70463 |
9/27/2001 |
WO |
A |
US Referenced Citations (3)
Number |
Name |
Date |
Kind |
5129919 |
Kalinowski et al. |
Jul 1992 |
A |
5863308 |
Qi et al. |
Jan 1999 |
A |
6074278 |
Wu et al. |
Jun 2000 |
A |
Provisional Applications (1)
|
Number |
Date |
Country |
|
60/191607 |
Mar 2000 |
US |