An abrasive article having certain minimum levels of permeability to fluids comprises about 40 to 80%, by volume interconnected porosity and effective amounts of abrasive grain and bond to carry out soft grinding and deep cut grinding operations. The high permeability to the passage of fluids and interconnected porosity provides an open structure of channels to permit the passage of fluid through the abrasive article and the removal of swarf from the workpiece during grinding operations.
A method is provided for fabricating an abrasive article having porosity. The method includes blending a mixture of abrasive grain, bond material, and pore inducer, in which the pore inducer is soluble in a supercritical fluid, and the abrasive grain and bond material are substantially insoluble in the supercritical fluid. The mixture is pressed into an abrasive laden composite and exposed to the supercritical fluid for a period of time suitable to dissolve at least a portion of the pore inducer. The composite is thermally processed.
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.
An additive impregnated abrasive article and method for fabricating the same is provided. The method includes providing an abrasive article having a pore structure, dissolving an additive in a supercritical fluid, and exposing the abrasive article to the additive-laden supercritical fluid, so that the fluid disperses through the pore structure. The supercritical fluid is then brought to below its critical point for a period of time sufficient to dissociate the additive from the fluid, so that the additive is deposited within the pore structure of the abrasive article.
An abrasive article made from a plurality of abrasive composites bonded to form a three dimensional abrasive article. Each abrasive composite includes a plurality of primary abrasive particles bonded together by a first binder matrix to form a shaped or irregular abrasive composite. Present within the abrasive composite is an intra-composite porosity between and among the primary abrasive particles. Inter-composite porosity is present within the abrasive article between and among the abrasive composites. The abrasive article is used to grind glass and other workpiece surfaces to a mirror finish.
