Method for making vitreous bonded abrasive article and article made by the method
First Claim
1. An improved method for making a vitreous bonded abrasive article having a porosity in the range of from 20 to 55% by volume comprising the steps ofa) blending together abrasive grains and vitreous matrix precursor to form a uniform mixture,b) placing the mixture in a mold,c) compressing the mixture while in the mold and to form a compressed shape,d) heating the compressed shape at a temperature for converting the vitreous matrix precursor to a vitreous matrix binding together the abrasive grains,the improvement comprising the step of mixing a shrinkage reducing effective amount of a shrinkage control agent selected from the group consisting of minerals containing oxygen and a least one of the elements of silicon, aluminum and magnesium and hexagonal boron nitride having a hardness in the range of from 1 to 4 on the Mohs scale with the abrasive grains and vitreous matrix precursor, said agent being an unclad, non-abrasive, non metallic, particulate inorganic solid.
14 Assignments
0 Petitions
Accused Products
Abstract
A method for making vitreous bonded grinding wheels having a porosity of from 20 to 55% by volume is provided that reduces or prevent shrinkage. The method includes a step of mixing unclad, non-abrasive, non-metallic, particulate, inorganic solid shrinkage control agent with the abrasive grain, vitreous matrix precursor and other ingredients for producing the wheel. Non-abrasive hexagonal boron nitride is a preferred shrinkage control agent and may be used in amounts ranging for 1 to 10% by volume based on the volume of the grinding wheel. Reduced shrinkage of wheels made by the method over comparable wheels made without the shrinkage control agent is obtained.
-
Citations
18 Claims
-
1. An improved method for making a vitreous bonded abrasive article having a porosity in the range of from 20 to 55% by volume comprising the steps of
a) blending together abrasive grains and vitreous matrix precursor to form a uniform mixture, b) placing the mixture in a mold, c) compressing the mixture while in the mold and to form a compressed shape, d) heating the compressed shape at a temperature for converting the vitreous matrix precursor to a vitreous matrix binding together the abrasive grains, the improvement comprising the step of mixing a shrinkage reducing effective amount of a shrinkage control agent selected from the group consisting of minerals containing oxygen and a least one of the elements of silicon, aluminum and magnesium and hexagonal boron nitride having a hardness in the range of from 1 to 4 on the Mohs scale with the abrasive grains and vitreous matrix precursor, said agent being an unclad, non-abrasive, non metallic, particulate inorganic solid.
-
15. A vitreous bonded abrasive article having a porosity in the range of from 20 to 55% by volume produced by an improved method comprising the steps of
a) blending together abrasive grains and vitreous matrix precursor to form a uniform mixture, b) placing the mixture in a mold, c) compressing the mixture while in the mold to form a compressed shape and d) heating the compressed shape at a temperature for converting the vitreous matrix precursor to a vitreous matrix binding together the abrasive grains, the improvement comprising the step of mixing a shrinkage reducing effective amount of a shrinkage control agent selected from the group consisting of minerals containing oxygen and a least one of the elements of silicon, aluminum and magnesium and hexagonal boron nitride having a hardness in the range of from 1 to 4 on the Mohs scale with the abrasive grains and vitreous matrix precursor, said agent being an unclad, non-abrasive, non-metallic, particulate, inorganic solid.
Specification