Abrasive Tool

Abstract

Abrasive material such as diamonds are transported onto a ferromagnetic tool blank from a suspension of brazing flux and diamonds coated with ferromagnetic material. The tool blank is prepared by coating a receptor site with brazing alloy. A magnetic field is applied to the tool blank, and the coated receptor site is placed in contact with the suspension. The receptor site is heated to brazing temperatures to liquefy the coating, allowing diamonds from the suspension to be transported by magnetism to load the liquefied brazing alloy, forming a matrix at the receptor site.

1 . The method of forming an abrasive tool, comprising:
 mixing brazing flux and abrasive material to form a suspension of said flux and said abrasive material, wherein the abrasive material is coated with a ferromagnetic substance;   providing a tool blank formed of ferromagnetic substance, wherein said tool blank has one or more selected receptor sites thereon for receiving abrasive material;   applying brazing alloy to said one or more selected receptor sites;   contacting said suspension with the tool blank at said one or more selected receptor sites;   during said contact between the suspension and receptor sites,
 (a) causing the tool blank to be magnetic; 
 (b) causing the brazing alloy on the receptor sites to be in a liquefied state; and 
 (c) transporting abrasive material from the suspension to said liquefied brazing alloy under magnetic force of the tool blank; 
   whereby a matrix of abrasive material and brazing alloy is formed at the receptor sites of the tool blank; and   solidifying the matrix, thereby forming an abrasive tool.   
     
     
         2 . The method of  claim 1 , wherein:
 said abrasive material is chosen from the group consisting of diamonds, cubic boron nitride, super abrasives, and combinations thereof.   
     
     
         3 . A method of forming an abrasive drill bit, comprising:
 mixing brazing flux and abrasive material to form a suspension of said flux and said abrasive material, wherein the abrasive material is coated with a ferromagnetic substance;   providing a drill rod blank formed of ferromagnetic substance, wherein said drill rod blank has opposite proximal and distal ends;   applying brazing alloy to said distal end of the drill rod blank;   placing the distal end of the drill rod blank with said applied brazing alloy thereon in selected proximity to said suspension;   applying a magnetic field to the drill rod blank, sufficient to cause the drill rod blank to be magnetic, wherein said magnetic field is of sufficient strength with respect to said selected proximity between the drill rod blank and the suspension so as to cause the magnetism of the drill rod blank to transport said coated abrasive material from the suspension to the drill rod blank;   while said drill rod blank is in the selected proximity to the suspension, causing the distal end of the drill rod blank to be at a temperature sufficient to maintain said brazing alloy on the distal end thereof in a liquefied state such that the coated abrasive material transported to the drill rod blank enters the liquefied brazing alloy, thereby forming a matrix of abrasive material and brazing alloy on the distal end of the drill bit blank, forming an abrasive drill bit; and   cooling the abrasive drill bit to solidify the brazing alloy.   
     
     
         4 . The method of  claim 3 , wherein:
 silver is a component of said brazing alloy.   
     
     
         5 . The method of  claim 4 , wherein:
 said brazing alloy is composed of silver in a concentration ranging from 45% to 55% by volume.   
     
     
         6 . The method of  claim 3 , wherein:
 nickel is a component of said ferromagnetic substance that coats said abrasive material.   
     
     
         7 . The method of  claim 6 , wherein:
 said ferromagnetic substance that coats said abrasive material is an alloy of nickel.   
     
     
         8 . The method of  claim 7 , wherein:
 said ferromagnetic substance that coats said abrasive material is a TiNi alloy.   
     
     
         9 . The method of  claim 3 , wherein:
 said selected proximity of the distal end of the drill rod blank to said suspension is direct contact.   
     
     
         10 . The method of  claim 9 , wherein:
 said selected proximity of said distal end of the drill rod blank to said suspension is at least partial immersion of the distal end into the suspension.   
     
     
         11 . The method of  claim 3 , wherein:
 Said abrasive material is chosen from the group consisting of diamonds, cubic boron nitride, super abrasives, and combinations thereof.   
     
     
         12 . A method of forming an abrasive drill bit, comprising:
 mixing brazing flux and abrasive material to form a suspension of said flux and said abrasive material, wherein the abrasive material is coated with a ferromagnetic substance;   providing a drill rod blank formed of ferromagnetic substance, wherein said drill rod blank has opposite proximal and distal ends;   applying brazing alloy to said distal end of the drill rod blank;   contacting said suspension with the distal end of the drill rod blank with said applied brazing alloy thereon;   during said contact between the suspension and drill rod blank,
 (a) causing the drill rod blank to be magnetic; 
 (b) causing brazing alloy on the distal end of the drill rod blank to be in a liquefied state; and 
 (c) transporting abrasive material from the suspension to the liquefied brazing alloy under magnetic force of the drill rod blank; 
   whereby a matrix of abrasive material and brazing alloy is formed on the distal end of the drill bit blank; and   solidifying the matrix, thereby forming an abrasive drill bit.   
     
     
         13 . The method of  claim 12 , wherein:
 Said abrasive material is chosen from the group consisting of diamonds, cubic boron nitride, super abrasives, and combinations thereof.