Vitrified grinding stone having open and homogeneous structure

Abstract

A vitrified grinding stone having an open and homogeneous structure in which an abrasive grain and an inorganic hollow filler are bonded by an inorganic bonding agent, the abrasive grain is filled at a proportion by volume fraction of 23 to 35 vol %, and has homogeneity with a standard deviation of 10 or less in a frequency distribution chart of an area ratio of an abrasive grain, which is a distribution chart of proportions of a solid matter including the abrasive grain per unit area at a plurality of locations in a cross section of the vitrified grinding stone.

1 . A vitrified grinding stone having an open and homogeneous structure in which an abrasive grain and an inorganic hollow filler are bonded by an inorganic bonding agent, wherein the abrasive grain is filled at a proportion by volume fraction of 23 to 35 vol %, and has homogeneity with a standard deviation of 10 or less in a frequency distribution chart of an area ratio of an abrasive grain, which is a distribution chart of proportions of a solid matter including the abrasive grain per unit area at a plurality of locations in a cross section of the vitrified grinding stone. 
     
     
         2 . The vitrified grinding stone having the open and homogeneous structure according to  claim 1 , wherein the inorganic hollow filler has an average particle diameter of 1.6 times or less with respect to the abrasive grain. 
     
     
         3 . The vitrified grinding stone having the open and homogeneous structure according to  claim 1 , wherein the inorganic hollow filler is included 0.2 times to 1.7 times with respect to the volume fraction of the abrasive grain in a volume fraction. 
     
     
         4 . The vitrified grinding stone having the open and homogeneous structure according to  claim 1 , wherein the inorganic bonding agent is included within 10 to 15 vol % in a volume fraction. 
     
     
         5 . The vitrified grinding stone having the open and homogeneous structure according to  claim 1 , wherein homogeneity with a standard deviation of 6.5 to 8.7 in the frequency distribution chart of the area ratio of an abrasive grain is provided. 
     
     
         6 . The vitrified grinding stone having the open and homogeneous structure according to  claim 1 , wherein the inorganic hollow filler is included within 4 to 45 vol % in a volume fraction. 
     
     
         7 . The vitrified grinding stone having the open and homogeneous structure according to  claim 1 , wherein the inorganic hollow filler has an average particle diameter of 0.6 to 1.6 times with respect to the abrasive grain. 
     
     
         8 . The vitrified grinding stone having the open and homogeneous structure according to  claim 1 , wherein the inorganic hollow filler has a volume fraction of 0.2 to 1.67 times with respect to the volume fraction of the abrasive grain. 
     
     
         9 . The vitrified grinding stone having the open and homogeneous structure according to  claim 1 , wherein the abrasive grain is an alumina abrasive or a silicon carbide abrasive, and the abrasive grain has a grain size of F80 to F120.