Bonded abrasive article

Abstract

A bonded abrasive article includes, on a total weight basis: 30 to 37 percent of ceramic-coated blue fused aluminum oxide particles; 30 to 37 percent of non-seeded sol-gel alumina-based abrasive particles, wherein the non-seeded sol-gel alumina-based abrasive particles are composed of crystallites of alpha alumina, magnesium alumina spinel, and rare earth hexagonal aluminate; a phenolic binder that comprises a reaction product of 8 to 12 percent by weight of curable novolac phenolic resin and 2.1 to 5.1 percent by weight of curable resole phenolic resin; 3 to 6 percent by weight of metal fibers having a length of 5 millimeters or less; 8 to 11 percent by weight of cryolite; and 0.1 to 0.3 percent by weight of electrically conductive particles. Methods of making and using the bonded abrasive article are also disclosed.

1 . A bonded abrasive article comprising, on a total weight basis: 30 to 37 percent by weight of ceramic-coated blue fused aluminum oxide particles; 30 to 37 percent by weight of non-seeded sol-gel alumina-based abrasive particles, wherein the non-seeded sol-gel alumina-based abrasive particles are composed of crystallites of alpha alumina, magnesium alumina spinel, and rare earth hexagonal aluminate; a phenolic binder that comprises a reaction product of 8 to 12 percent by weight of curable novolac phenolic resin and 2.1 to 5.1 percent by weight of curable resole phenolic resin; 3 to 6 percent by weight of metal fibers having a length of 5 millimeters or less; 8 to 11 percent by weight of cryolite; and 0.1 to 0.3 percent by weight of electrically conductive particles. 
     
     
         2 . The bonded abrasive article of  claim 1 , wherein the metal fibers comprise aluminum fibers. 
     
     
         3 . The bonded abrasive article of  claim 1 , further comprising 8 to 11 percent by weight of polytetrafluorethylene particles. 
     
     
         4 . The bonded abrasive article of  claim 1 , wherein the bonded abrasive article comprises a cut-off wheel. 
     
     
         5 . A method of making a bonded abrasive article, the method comprising:
 combining, on a total weight basis: 30 to 37 percent by weight of ceramic-coated blue fused aluminum oxide particles; 30 to 37 percent by weight of non-seeded sol-gel alumina-based abrasive particles, wherein the non-seeded sol-gel alumina-based abrasive particles are composed of crystallites of alpha alumina, magnesium alumina spinel, and rare earth hexagonal aluminate; 8 to 12 percent by weight of curable novolac phenolic resin; 2.1 to 5.1 percent by weight of curable resole phenolic resin; 3 to 6 percent by weight of metal fibers having a length of 5 millimeters or less; 8 to 11 percent by weight of cryolite; 0.1 to 0.3 percent of a silane coupling agent; and 0.1 to 0.3 percent by weight of electrically conductive particles; and   curing the curable novolac phenolic resin and curable resole phenolic resin.   
     
     
         6 . The method of  claim 5 , wherein the metal fibers comprises short aluminum fibers. 
     
     
         7 . The method of  claim 5 , wherein the silane coupling agent comprises a gamma-aminopropyltrialkoxysilane. 
     
     
         8 . The method of  claim 5 , further comprising 8 to 11 percent by weight of polytetrafluorethylene particles. 
     
     
         9 . The method of  claim 5 , wherein the bonded abrasive article comprises a cut-off wheel.