Metal cutting inserts with abrasive bodies

Abstract

The present invention relates to a cutting tool insert of a generally polygonal shape provided with a ceramic tip in a recess in at least one of its corners with a bottom surface and at least one side surface. At least the bottom surface of the recess is provided with rails with a height h being from about 50 to about 100 μm, width w being from about 100 to about 200 μm and spaced at distance l from about 0.75 to about 1.25 mm. The invention also relates to a method of making such an insert using a grinding wheel of a suitable profile before or after sintering or in the pressing operation.

1 . A cutting tool insert, comprising:
 a body with a generally polygonal shape;   a recess in at least one of corner of the body, the recess with a bottom surface and at least one side surface; and   a ceramic tip brazed in the recess,   wherein at least the bottom surface of the recess is provided with rails with a height h of from about 50 to about 100 μm, a width w of from about 100 to about 200 μm and spaced at a distance l of from about 0.75 to about 1.25 mm.   
   
   
       2 . The cutting tool insert of  claim 1 , wherein one of the bottom surface and the at least one side surface are planar. 
   
   
       3 . The cutting tool insert of  claim 1 , wherein the recess provides a mechanical interlock. 
   
   
       4 . The cutting tool insert of  claim 1 , wherein the ceramic tip is of PCD and/or cBN. 
   
   
       5 . The cutting tool insert of  claim 1 , wherein the side surface is provided with rails. 
   
   
       6 . The cutting tool insert of  claim 1 , wherein the recess includes a corner relief radius. 
   
   
       7 . The cutting tool insert of  claim 1 , wherein a surface of the ceramic tip in contact with the bottom surface of the recess is essentially planar. 
   
   
       8 . The cutting tool insert of  claim 1 , wherein a surface of the ceramic tip in contact with the at least one side surface of the recess is essentially planar. 
   
   
       9 . The cutting tool insert of  claim 1 , wherein the bottom surface and the at least one side surface meet at a corner radius. 
   
   
       10 . The cutting tool insert of  claim 9 , wherein the corner radius includes a corner relief radius. 
   
   
       11 . A method of making a cutting tool insert, comprising:
 forming a recess in at least one corner of a body of the insert, wherein the body has a generally polygonal shape; and   securing a ceramic tip in the recess,   wherein the recess includes a bottom surface and at least one side surface,   wherein at least the bottom surface of the recess includes rails with a height h of from about 50 to about 100 μm, a width w of from about 100 to about 200 μm and spaced at a distance l of from about 0.75 to about 1.25 mm apart.   
   
   
       12 . The method of  claim 11 , wherein the rails are made by grinding after sintering. 
   
   
       13 . The method of  claim 11 , wherein the rails are made by grinding before sintering. 
   
   
       14 . The method of  claim 11 , wherein the rails are made in a pressing operation. 
   
   
       15 . The method of  claim 11 , wherein the ceramic tip is of PCD and/or cBN. 
   
   
       16 . The method of  claim 11 , wherein the side surface includes rails. 
   
   
       17 . The method of  claim 16 , wherein the rails on the side surface are made by grinding after sintering. 
   
   
       18 . The method of  claim 16 , wherein the rails on the side surface are made by grinding before sintering. 
   
   
       19 . The method of  claim 16 , wherein the rails on the side surface are made in a pressing operation. 
   
   
       20 . The method of  claim 16 , wherein the method comprises forming a corner relief radius for the recess. 
   
   
       21 . The method of  claim 16 , wherein the recess and the rails are simultaneously formed. 
   
   
       22 . The method of  claim 16 , wherein the ceramic tip is of PCD and/or cBN. 
   
   
       23 . The method of  claim 16 , wherein securing includes brazing the ceramic tip into the recess. 
   
   
       24 . The method of  claim 23 , wherein a gap between the ceramic tip and the recess is substantially filled with brazing material. 
   
   
       25 . The method of  claim 11 , comprising forming a corner relief radius for the recess. 
   
   
       26 . The method of  claim 11 , wherein securing includes brazing the ceramic tip into the recess. 
   
   
       27 . The method of  claim 26 , wherein a gap between the ceramic tip and the recess is substantially filled with brazing material. 
   
   
       28 . The method of  claim 11 , wherein the recess and the rails are simultaneously formed.