Uncured molded abrasive articles having low volatile organic chemical content are prepared using water as a temporary binder. The abrasive articles preferably contain a uniformly coated abrasive grain comprising a novolac resin having a phenol:formaldehyde ratio of 1:0.2 to 1:0.35 and containing less than 0.5% free phenol.
The abrasive particle layer of resin bonded abrasive tool is constructed by resin binder phase consisting of heat hardening resin, for example, phenol resin etc. and super abrasive particle of diamond (or CBN etc.) distributed in this resin binder phase. The wear resistant filler consisting of SiC, for example, as hard filler and hollow glass and metal coated amorphous carbon is distributed in resin binder phase. The amorphous carbon is made to spherical shape and metal coating layer consisting of Cu, for example, as the metal having high thermal conductivity, is set on a surface of this amorphous carbon.
An abrasive article including from about 40 to about 80 volume percent interconnected porosity, the article being useful as a segment for a segmented grinding wheel, and a method for fabricating the same. The method includes blending a mixture of abrasive grain, bond material and dispersoid particles, the mixture including from about 40 to about 80 volume percent dispersoid particles. In one embodiment the mixture includes from about 50 to about 80 volume percent dispersoid particles. In another embodiment the mixture includes an organic bond material and from about 40 to about 80 volume percent dispersoid particles. The powder mixture is then pressed into an abrasive laden composite and thermally processed. After cooling the composite is immersed into a solvent, which dissolves substantially all of the dispersoid particles, leaving a highly porous, bonded abrasive article.
An abrasive article including from about 40 to about 80 volume percent interconnected porosity, the article being useful as a segment for a segmented grinding wheel, and a method for fabricating the same. The method includes blending a mixture of abrasive grain, bond material and dispersoid particles, the mixture including from about 40 to about 80 volume percent dispersoid particles. In one embodiment the mixture includes from about 50 to about 80 volume percent dispersoid particles. In another embodiment the mixture includes an organic bond material and from about 40 to about 80 volume percent dispersoid particles. The powder mixture is then pressed into an abrasive laden composite and thermally processed. After cooling the composite is immersed into a solvent, which dissolves substantially all of the dispersoid particles, leaving a highly porous, bonded abrasive article.
Granular molding materials for fabricating abrasive articles, such as, for example, grinding wheels, are produced by mixing heated abrasive grains with a resin blend including two phenol-novolac resins. Preferably, the resin blend is added to the abrasive grains in the mixer apparatus of the invention, which can be a bowl type mixer. The mixer can be preheated by directing a heated gas, such as air, across the mixer. The granular molding material can also include a curing agent, fillers and other materials generally employed in fabricating abrasive articles.
