Grinding means and method for producing the grinding means

Abstract

The invention relates to a grinding means ( 1 ) for grinding workpieces, comprising: a carrier ( 2 ), e.g., a carrier disk or a carrier strip, abrasive grains ( 4 ) applied to the carrier ( 2 ), and a binder ( 6 ) applied to the carrier ( 2 ). To enable material saving and energy efficient production nanoparticles ( 8 ) are held in the binder ( 6 ) which comprise a superparamagnetic, ferrimagnetic and/or ferromagnetic material which can be excited by means of one or more of the following measures: an alternating electric induction field, an alternating magnetic field microwave radiation, where the nanoparticles ( 8 ) can be heated by means of the excitation, and where the binder ( 6 ) thermally cures. Furthermore, a method for producing is provided.

1 - 34 . (canceled) 
     
     
         35 . A grinding means for grinding workpieces, the grinding means comprising:
 a carrier,   abrasive grains applied to the carrier, and   at least one binder applied to the carrier,   wherein nanoparticles are held in the binder, the nanoparticles comprise a superparamagnetic, ferromagnetic, and/or ferromagnetic material which can be excited by means of one or more of the following measures:   an alternating electric induction field,   an alternating magnetic field,   microwave radiation,   where the nanoparticles can be heated by means of the excitation, and whereby the binder thermally cures.   
     
     
         36 . The grinding means of  claim 35 , wherein the binder is endogenously thermally cured, at least in part, by means of the heating of the nanoparticles, e.g., by means of a polarity switch of the nanoparticles. 
     
     
         37 . The grinding means of  claim 35 , wherein the nanoparticles are made exclusively from a material which can be excited in an alternating electric or magnetic field for switching the polarity, whereby heat energy can be induced in the binder. 
     
     
         38 . The grinding means of  claim 35 , wherein a concentration of the nanoparticles in the binder lies in the range from 1 to 30% by weight, e.g., 5 to 25 Ge % by weight, preferably 10 to 20% by weight, in relation to the total weight of the binder layer. 
     
     
         39 . The grinding means of  claim 38 , wherein the binder includes a resin component and, in particular, further substances, e.g., fillers, where the concentration of the nanoparticles ( 8 ) relative to the resin component lies at 3 to 30% by weight, preferably 10 to 25% by weight. 
     
     
         40 . The grinding means of  claim 35 , wherein at least one binder layer including the binder is applied to the carrier, and abrasive grains are held in the binder layer, in particular, in a lower binder layer applied directly on the carrier. 
     
     
         41 . The grinding means of  claim 35 , wherein the binder including the nanoparticles is applied as a top layer on one or more lower layers, e.g., a lower layer including abrasive grains. 
     
     
         42 . The grinding means of  claim 35 , wherein a plurality of binder layers are provided, e.g., one lower binder layer and one or more top layers, where the plurality of binder layers exhibit different concentrations of nanoparticles and/or different Curie temperatures of their nanoparticles. 
     
     
         43 . The grinding means of claim  43 , wherein one or more of the binder layers, in particular, a top layer, is formed without nanoparticles. 
     
     
         44 . The grinding means of  claim 35 , wherein the magnetic material of the magnetic nanoparticles is one or more of the following materials:
 a metal oxide, in particular, Mn x Zn 1-x Fe 2 O 4 , where x=0.2 to 0.6, e.g., 0.3 to 0.5 and   an iron oxide, in particular, Fe 3 O 4  and/or Fe 2 O 3 .   
     
     
         45 . The grinding means of  claim 35 , wherein the magnetic nanoparticles have a primary particle size of 2 to 200 nm, in particular, 10 nm to 150 nm, in particular, 10 to 100 nm, preferably 10 to 30 nm. 
     
     
         46 . The grinding means of  claim 35 , wherein the abrasive grains are shaped abrasive grains. 
     
     
         47 . The grinding means of  claim 46 , wherein the abrasive grains are formed plane-parallel and with a triangular upper side and underside, and stand on an edge on the carrier, with their tips pointing upwards and/or pointing upwards at an angle of inclination. 
     
     
         48 . The grinding means of  claim 35 , wherein the abrasive grains are formed flaky and/or plane-parallel. 
     
     
         49 . The grinding means of  claim 35 , wherein the abrasive grains are aligned in parallel in such a manner that their tips are arranged at about the same level above the carrier. 
     
     
         50 . The grinding means of  claim 35 , wherein the abrasive grains are made from one or more of the following materials: zirconia alumina, alpha-alumina, silicon carbide, diamond, and crushed cubic boron nitride (CBN). 
     
     
         51 . The grinding means of  claim 35 , wherein the carrier is formed from a disc or a band, e.g., made from a textile fabric, paper, plastics. 
     
     
         52 . The grinding means of  claim 35 , wherein a Curie temperature of the nanoparticles lies above a curing temperature of the binder, in particular, within a range of 20° C., preferably 10° C., above the curing temperature of the binder, to avoid overheating of the binder. 
     
     
         53 . The grinding means of  claim 35 , wherein the binder is formed by mixing one or several resins and one or several hardening agents, where the resin is selected, e.g., from the following group: epoxy resins, acrylates, phenolic resins, and polyurethanes. 
     
     
         54 . A method for producing a grinding means, wherein at least one binder layer and abrasive grains are applied onto a carrier, and a binder of the binder layer is cured, wherein nanoparticles are held in the binder, and, upon curing of the binder and/or after the curing of the binder, the nanoparticles are excited and/or alternatingly polarized thereby heating up, whereby the binder, by virtue of the heating of the nanoparticles, is cured, at least in part, and/or is post-cured after curing. 
     
     
         55 . The method of  claim 54 , comprising at least the following steps:
 providing the carrier, the abrasive grains, the binder, and the nanoparticles,   applying the abrasive grains and the binder onto the carrier,   curing and/or post-curing of the binder, at least in part, by activating and/or exciting the nanoparticles thereby producing heat,   where the binder, at least in part, is cured by the heat generated by the nanoparticles and/or post-cured.   
     
     
         56 . The method of  claim 55 , wherein at first the binder including the nanoparticles is applied onto the carrier and subsequently the abrasive grains are introduced into the binder by scattering. 
     
     
         57 . The method of  claim 55 , wherein the binder is applied with abrasive grains contained therein, e.g., by means of a brush coating method or brush application. 
     
     
         58 . The method of  claim 54 , wherein the nanoparticles are introduced, e.g., mixed in, into the binder in advance. 
     
     
         59 . The method of  claim 54 , wherein the binder is applied as a binder layer, e.g., as lower binder layer, for holding the abrasive grains, and/or as top layer and/or as second top layer. 
     
     
         60 . The method of  claim 54 , wherein the binder is cured and/or post-cured, at least in part, by means of an alternating magnetic field, for activating the nanoparticles, in particular, with the characteristics: frequency 100 to 1.000 kHz and field strength 4.000 to 21.000 A/m. 
     
     
         61 . The method of  claim 54 , wherein the binder is cured and/or post-cured, at least in part, by means of microwave radiation, e.g., in a range from 1 to 10 GHz. 
     
     
         62 . The method of  claim 54 , wherein the binder is cured and/or post-cured, at least in part, by means of an electric induction field, e.g., in a range from 500 to 1500 kHz. 
     
     
         63 . The method of  claim 54 , wherein the step of aligning the abrasive grains happens by means of one or more of the following aligning methods:
 electrostatic alignment in an applied constant electrostatic field (E) and/or alternating field,   gravitatively by scattering.   
     
     
         64 . The method of  claim 54 , wherein upon curing of the binder, additionally or exclusively, thermal energy is fed, e.g., in a furnace. 
     
     
         65 . The method of  claim 54 , wherein the magnetic nanoparticles lose their magnetic properties upon reaching their Curie temperature thereby providing an upper limit for a process temperature, where the Curie temperature lies above the curing temperature of the binder. 
     
     
         66 . The method of  claim 65 , wherein the Curie temperature lies below a critical upper temperature at which the grinding means can suffer damage. 
     
     
         67 . The method of  claim 54 , wherein for curing the binding the amount of energy is regulated, where the regulated amount of energy at least covers the energy fed in by the excitation of the nanoparticles. 
     
     
         68 . The method of  claim 67 , wherein for regulating the amount of energy a surface temperature, e.g., of the binder layer, is measured, and the amount of energy introduced is deduced from a process time and the measured surface temperature.