Tool blades

Abstract

There is provided a tool blade comprising a backing strip, binding material forming a binder layer, with discrete regions of binder layer formed as teeth along an edge of the backing strip, and abrasive particles bound to the backing strip by the binder layer, wherein each tooth is formed with a ductile region bonded to the backing strip, a crown and an intermediate region of thermal material disposed between the ductile region and the crown so as to absorb thermal expansion and contraction. The binding material powder is heated by laser beam to form a binder layer which binds the abrasive particles to the backing strip. The laser beam is used to form discrete regions of binder layer as teeth. The binding material is typically braze material.

What is claimed is: 
     
         1 . A tool blade, comprising:
 a backing strip;   binding material forming a binder layer, with discrete regions of binder layer formed as teeth along an edge of the backing strip;   and abrasive particles bound to the backing strip by the binder layer;   
       wherein:
 each tooth is formed with a ductile region bonded to the backing strip, a crown and an intermediate region of thermal material disposed between the ductile region and the crown so as to absorb thermal expansion and contraction. 
 
     
     
         2 . The tool blade according to  claim 1 , wherein the binding material includes a ductile braze material. 
     
     
         3 . The tool blade according to  claim 2 , wherein the ductile braze material is in combination with a binder material. 
     
     
         4 . The tool blade according to  claim 2 , wherein the ductile braze material is in the region of the binding layer which is bonded to the backing strip to provide a stress resistant bond with the backing strip. 
     
     
         5 . The tool blade according to  claim 2 , wherein the ductile braze material includes abrasive particles. 
     
     
         6 . The tool blade according to  claim 1 , wherein the intermediate region includes abrasive particles. 
     
     
         7 . The tool blade according to  claim 1 , wherein the binding material includes a hard braze material. 
     
     
         8 . The tool blade according to  claim 7 , wherein the hard braze material is a nickel braze material. 
     
     
         9 . The tool blade according to  claim 7 , wherein the hard braze material is in the region of the binding layer which is exposed during use of the blade, and which includes abrasive particles. 
     
     
         10 . The tool blade according to  claim 1 , wherein the abrasive particles are a super abrasive material. 
     
     
         11 . The tool blade according to  claim 1 , wherein a mixture of abrasive particles of different materials is used. 
     
     
         12 . The tool blade according to  claim 1 , wherein the abrasive particles are cubic boron nitride, diamond or tungsten carbide. 
     
     
         13 . The tool blade according to  claim 1 , wherein the abrasive particles are coated to promote binding with the binding layer. 
     
     
         14 . The tool blade according to  claim 13 , wherein the abrasive particles are coated by a physical vapour deposition or chemical vapour deposition technique. 
     
     
         15 . The tool blade according to  claim 13 , wherein the abrasive particles are coated with a material which promotes wetting of the abrasive particles by the binding material. 
     
     
         16 . The tool blade according to  claim 1 , wherein the backing strip is steel. 
     
     
         17 . The tool blade according to  claim 1 , wherein the backing strip has tooth roots along the edge of the strip, prior to the formation of the binder layer.