Bonded abrasive article

Abstract

The present invention relates to a bonded abrasive article comprising specific shaped abrasive particles and a bonding medium comprising a vitreous bond. The present invention also relates to the use of an article according to the present invention in grinding applications, in particular in high performance grinding applications and to the use of an article according to the present invention for abrading a workpiece material particularly a workpiece material selected from steels, non-ferrous metals, and alloys. In addition, the present invention relates to a method for abrading a workpiece, the method comprising frictionally contacting at least a portion of an abrasive article according to the invention with a surface of a workpiece; and moving at least one of the workpiece or the abrasive article to abrade at least a portion of the surface of the workpiece.

1 . A bonded abrasive article comprising shaped abrasive particles and a bonding medium comprising a vitreous bond, said shaped abrasive particles each comprising a first side and a second side separated by a thickness t, wherein said first side comprises a first face having a perimeter of a first geometric shape, wherein the thickness t is equal to or smaller than the length of the shortest side-related dimension of the particle. 
     
     
         2 . The article according to  claim 1 , wherein the shaped abrasive particles are ceramic shaped abrasive particles. 
     
     
         3 . The article according to  claim 1 , wherein the shaped abrasive particles comprise alpha alumina. 
     
     
         4 . The article according to  claim 1 , wherein the shaped abrasive particles comprise seeded or non-seeded sol-gel derived alpha alumina. 
     
     
         5 . The article according to  claim 1 , wherein said shaped abrasive particles comprise a major portion of aluminum oxide. 
     
     
         6 . The article according to  claim 5 , wherein said aluminum oxide is fused aluminum oxide. 
     
     
         7 . The article according to  claim 1 , further comprising secondary abrasive particles. 
     
     
         8 . The article according to  claim 7 , wherein the shaped and secondary abrasive particles are independently selected from particles of fused aluminum oxide materials, heat treated aluminum oxide materials, ceramic aluminum oxide materials, sintered aluminum oxide materials, silicon carbide materials, titanium diboride, boron carbide, tungsten carbide, titanium carbide, diamond, cubic boron nitride, garnet, fused alumina-zirconia, sol-gel derived abrasive particles, cerium oxide, zirconium oxide, titanium oxide or a combination thereof. 
     
     
         9 . The article according to  claim 7 , wherein the secondary abrasive particles are selected from crushed abrasive particles having a specified nominal grade. 
     
     
         10 . The article according to  claim 9 , wherein the crushed abrasive particles are of a smaller size than the shaped abrasive particles. 
     
     
         11 . The article according to  claim 7  wherein said secondary abrasive particles are selected from particles of fused aluminum oxide materials, particles of superabrasive materials or particles of silicon carbide materials. 
     
     
         12 . The article according to  claim 1  comprising 10 to 80% by volume of said shaped abrasive particles and 1 to 60% by volume of said bonding medium. 
     
     
         13 . The article according to  claim 1 , wherein said vitreous bond comprises, based on the total weight of the vitreous bond, 25 to 90% by weight of SiO 2 ; 0 to 40% by weight of B 2 O 3 ; 0 to 40% by weight of Al 2 O 3 ; 0 to 5% by weight of Fe 2 O 3 , 0 to 5% by weight of TiO 2 , 0 to 20% by weight of CaO; 0 to 20% by weight of MgO; 0 to 20% by weight of K 2 O; 0 to 25% by weight of Na 2 O; 0 to 20% by weight of Li 2 O; 0 to 10% by weight of ZnO; 0 to 10% by weight of BaO; and 0 to 5% by weight of metallic oxides. 
     
     
         14 . The article according to  claim 1 , wherein the vitreous bond is obtainable from a vitreous bond precursor composition comprising frit. 
     
     
         15 . The article according to  claim 1 , comprising porosity. 
     
     
         16 . The article according to  claim 7  wherein the shaped abrasive particles and the secondary abrasive particles are comprised in a blend, wherein the content of the secondary abrasive particles is up to 95% by weight based on the total amount of abrasive particles present in the blend. 
     
     
         17 . The article according to  claim 1 , wherein said first geometric shape is selected from polygonal shapes, lense-shapes, lune-shapes, circular shapes, semicircular shapes, oval shapes, circular sectors, circular segments, drop-shapes and hypocycloids. 
     
     
         18 . The article according to  claim 1  wherein said first geometric shape is selected from triangular shapes and quadrilateral shapes 
     
     
         19 . The article according to  claim 1 , comprising at least one sidewall. 
     
     
         20 . The article according to  claim 19 , wherein the at least one sidewall is a sloping sidewall. 
     
     
         21 . The article according to  claim 1 , wherein said shaped abrasive particles each comprise at least one shape feature selected from: an opening, at least one recessed (or concave) face; at least one face which is shaped outwardly (or convex); at least one side having a plurality of grooves or ridges; at least one fractured surface; a low roundness factor; a perimeter of the first face comprising one or more corner points having a sharp tip; a second side comprising a second face having a perimeter comprising one or more corner points having a sharp tip; or a combination of one or more of said shape features. 
     
     
         22 . The article according to  claim 1 , wherein the shaped abrasive particles each have an opening. 
     
     
         23 . The article according to  claim 1 , wherein the shaped abrasive particles further comprise a plurality of grooves and/or ridges on the second side. 
     
     
         24 . The article according to  claim 1  wherein the second side comprises a vertex or a ridge line or a second face. 
     
     
         25 . The article according to  claim 24 , wherein the second side comprises a second face separated from the first side by thickness t and at least one sidewall connecting the second face and the first face. 
     
     
         26 . The article according to  claim 25 , wherein the second face has a perimeter of a second geometric shape which may be the same or different to the first geometric shape. 
     
     
         27 . The article according to  claim 26  wherein said first and second geometric shapes are independently selected from regular polygons, irregular polygons, lenses, lunes, circulars, semicirculars, ovals, circular sectors, circular segments, drop-shapes and hypocycloids. 
     
     
         28 . The article according to  claim 26  wherein the first and second geometric shapes have identical geometric shapes which may or may not be different in size. 
     
     
         29 . The article according to  claim 28 , wherein said identical geometric shapes are both selected either from triangular shapes or from quadrilateral shapes. 
     
     
         30 . The article according to  claim 25 , wherein the first face and the second face are substantially parallel or non-parallel to each other. 
     
     
         31 . The article according to  claim 25 , wherein the first and/or the second face are substantially planar. 
     
     
         32 . The article according to  claim 25 , wherein at least one of the first and second face is a non-planar face. 
     
     
         33 . The article according to  claim 32 , wherein at least one of the first and the second face is shaped inwardly. 
     
     
         34 . The article according to  claim 33 , wherein the first face is shaped inwardly and the second face is substantially planar or the first face is shaped outwardly and the second face is shaped inwardly or the first face is shaped inwardly and the second face is shaped inwardly. 
     
     
         35 . The article according to  claim 25 , wherein the second side comprises a second face and four facets intersecting the second face at a draft angle alpha forming a truncated pyramid. 
     
     
         36 . The article according to  claim 24 , wherein the second side comprises a vertex separated from the first side by thickness t and at least one sidewall connecting the vertex and the perimeter of the first face. 
     
     
         37 . The article according to  claim 36 , wherein the perimeter of the first face is trilateral, quadrilateral or higher polygonal and wherein the second side comprises a vertex and the corresponding number of facets for forming a pyramid. 
     
     
         38 . The article according to  claim 37 , wherein the perimeter of the first face is trilateral and wherein the shaped abrasive particles have four major sides joined by six common edges, wherein each one of the four major sides contacts three other of the four major sides, and wherein the six common edges have substantially the same length. 
     
     
         39 . The article according to  claim 24 , wherein the second side comprises a ridge line separated from the first side by thickness t and at least one sidewall connecting the ridge line and the perimeter of the first face. 
     
     
         40 . The article according to  claim 39 , wherein the sidewall comprises one or more facets connecting the ridge line and the perimeter of the first face. 
     
     
         41 . The article according to  claim 39 , wherein the first geometric shape is selected from quadrilateral geometric shapes and the sidewall comprises four facets forming a roof-shaped particle. 
     
     
         42 . The article according to  claim 1  having a three-dimensional shape selected from the shape of a wheel, honing stone, grinding segment, mounted points, or other shapes. 
     
     
         43 . The article according to  claim 1 , wherein the article comprises a wheel. 
     
     
         44 . The article according to  claim 43 , wherein the wheel is selected from grinding wheels for cylindrical grinding, centerless grinding, surface and profile grinding, reciprocating grinding, creep-feed grinding, grinding in generating methods of gears, threads, tools, camshafts, crankshafts bearings, and guard rails. 
     
     
         45 . The article according to  claim 1 , wherein the shaped abrasive particles are homogeneously distributed in the abrasive article. 
     
     
         46 . The article according to  claim 1 , wherein the shaped abrasive particles are non-homogeneously distributed in the abrasive article. 
     
     
         47 . The article according to  claim 46 , which is or comprises a bonded abrasive wheel, the wheel comprising an outer zone and an inner zone, wherein the compositions of the inner and outer zone differ in one or more aspects selected from the composition of the bond, the shape of abrasive particles, the grit size of abrasive particle, and the amount of abrasive particles. 
     
     
         48 . A bonded abrasive article according to  claim 1 , wherein the article comprises a blend of said shaped abrasive particles and secondary abrasive particles, wherein the amount of shaped abrasive particles ranges from 20 to 60% by weight, based on the total weight of abrasive particles in the blend. 
     
     
         49 . A bonded article according to  claim 1 , wherein the article is an article for gear grinding. 
     
     
         50 . Use of an article according to  claim 1  in high performance grinding applications. 
     
     
         51 . Use according to  claim 50  for outer diameter grinding with a Q′ w  of at least 1.5 mm 3 /mm/sec, inner diameter grinding with a Q′ w  of at least 1 mm 3 /mm/sec, surface grinding with a Q′ w  of at least 1.5 mm 3 /mm/sec, profile grinding with a Q′ w  of at least 3 mm 3 /mm/sec, profile grinding with generating method with a Q′ w  of at least 8 mm 3 /mm/sec, creep-feed grinding with a Q′ w  of at least 4 mm 3 /mm/sec, and camshaft grinding with a Q′ w  of at least 8 mm 3 /mm/sec. 
     
     
         52 . Use of an article according to  claim 1  for abrading a workpiece material selected from steels, non-ferrous metals, alloys, hard metals, ceramics and glasses. 
     
     
         53 . Method for abrading a workpiece, the method comprising frictionally contacting at least a portion of the abrasive article according to  claim 1  with a surface of a workpiece; and moving at least one of the workpiece or the abrasive article to abrade at least a portion of the surface of the workpiece. 
     
     
         54 . Method of gear grinding characterized by using a bonded abrasive article according to  claim 1 . 
     
     
         55 . Method of creep-feed grinding characterized by using a bonded abrasive article according to  claim 1 . 
     
     
         56 . Method of surface grinding characterized by using a bonded abrasive article according to  claim 1 . 
     
     
         57 . Method of cylindrical grinding characterized by using a bonded abrasive article according to  claim 1 . 
     
     
         58 . A method of grinding characterized by using a bonded abrasive article according to  claim 1 , wherein the specific chip volume V′ w  is at least 20% higher, than the specific chip volume achieved when using a comparable bonded abrasive article at the same specific material removal rate Q′ w .