Indexable cutting inserts and methods for producing the same

Abstract

A method of making a cutting insert includes: (i) forming a blank having a substrate and superhard material, the substrate having more than 4 pockets, the superhard material disposed within the pockets; (ii) removing cutting tips from the blank by cutting the blank along cutting lines; (iii) providing a cutting insert body having a plurality of cavities for receiving a corresponding number of cutting tips; (iv) inserting a cutting tip into each of the plurality of cavities; and (v) brazing the cutting tips to the cutting insert body. A related cutting insert includes: a cutting insert body having a plurality of cavities formed therein; a plurality of cutting tips, each of the plurality of cutting tips disposed in a respective cavity, the cutting tips having a geometry that provides a mechanical retention or lock when inserted into the cavities of the cutting insert body, said geometry including a generally trapezoidal anchor portion with its base substantially flat and spaced away form the cutting edge of the body, the cutting tips further being brazed in the cutting insert body.

1 . A method of making a cutting insert, the method comprising: 
 (i) forming a blank comprising a substrate and superhard material, the substrate having more than 4 pockets, the superhard material disposed within the pockets;    (ii) removing cutting tips from the blank by cutting the blank;    (iii) providing a cutting insert body having a plurality of cavities for receiving a corresponding number of cutting tips;    (iv) inserting a cutting tip into each of the plurality of cavities; and    (v) brazing the cutting tips to the cutting insert body.    
     
     
         2 . The method of  claim 1 , wherein the cutting insert is indexable.  
     
     
         3 . The method of  claim 1 , wherein the blank is generally disk-shaped.  
     
     
         4 . The method of  claim 1 , wherein the blank has the shape of a polygon.  
     
     
         5 . The method of  claim 1 , wherein the blank is provided with a through-hole.  
     
     
         6 . The method of  claim 1 , wherein the pockets have an arcuate shape.  
     
     
         7 . The method of  claim 1 , wherein the substrate is provided with at least 6 pockets.  
     
     
         8 . The method of  claim 1 , wherein the substrate is provided with at least 7 pockets.  
     
     
         9 . The method of  claim 1 , wherein the substrate is provided with at least 8 pockets.  
     
     
         10 . The method of  claim 1 , wherein the substrate is provided with at least 9 pockets.  
     
     
         11 . The method of  claim 1 , wherein the substrate is formed from a cemented carbide, cermet, or hard metal alloy.  
     
     
         12 . The method of  claim 11 , wherein the substrate is formed of a cemented carbide comprising WC and Co, the cemented carbide comprising 10-20 weight % Co.  
     
     
         13 . The method of  claim 1 , wherein step (i) further comprises introducing the superhard material in the form of a powder into the pockets.  
     
     
         14 . The method of  claim 13 , wherein step (i) further comprises pressing and sintering the blank thereby unifying the substrate and superhard material.  
     
     
         15 . The method of  claim 13 , wherein step (i) further comprises introducing the superhard material in the form of pre-pressed green bodies into the pockets.  
     
     
         16 . The method of  claim 15 , wherein step (i) further comprises sintering the blank thereby unifying the substrate and superhard material.  
     
     
         17 . The method of  claim 1 , wherein the superhard material comprises cubic boron nitride or polycrystalline diamond.  
     
     
         18 . The method of  claim 17 , wherein the superhard material further comprises at least one of a nitride, carbonitride, oxide or boride of a metal chosen from groups IVa-VIa of the Periodic Table.  
     
     
         19 . The method of  claim 17 , wherein the superhard material comprises a composite having a first phase comprising cubic boron nitride or polycrystalline diamond particles and a second phase comprising a metal, a metalloid, or alloys thereof.  
     
     
         20 . The method of  claim 1 , wherein the blank comprises a top surface and an opposing bottom surface, and the superhard material extends from the top surface to the bottom surface.  
     
     
         21 . The method of  claim 1 , wherein step (ii) comprises wire cutting to remove the cutting tips from the blank.  
     
     
         22 . The method of  claim 1 , wherein step (ii) comprises providing the cutting tips with a geometry that provides a mechanical retention or lock when inserted into the body of the cutting insert, said geometry including a generally trapezoidal anchor portion with its base substantially flat and spaced away from the cutting edge of the body.  
     
     
         23 . The method of  claim 1  wherein the cutting tip is provided with a generally dovetail shape.  
     
     
         24 . The method of  claim 23 , wherein the cutting tip is provided with a rounded forward nose and a pair of converging forward surfaces that meet at the nose.  
     
     
         25 . The method of  claim 24 , wherein at least the rounded forward nose portion of the cutting tip comprises the superhard material.  
     
     
         26 . The method of  claim 25 , wherein the superhard material is provided a leg length of at least 2 mm, the leg length being defined as distance between a first point on one of the converging forward surfaces where the superhard material is connected to the substrate material, and a second point defined by the point of intersection between two imaginary lines drawn along each of the converging forward surfaces.  
     
     
         27 . The method of  claim 26 , wherein the leg length is at least 3 mm.  
     
     
         28 . The method of  claim 24 , wherein the cutting tip is provided with a waisted section of reduced width.  
     
     
         29 . The method of  claim 28 , wherein the waisted section comprises a first pair of angled surfaces and a second pair of surfaces that meet at the section of reduced width.  
     
     
         30 . The method of  claim 29 , wherein the length of one surface of said second pair of surfaces is different from the other of said surfaces.  
     
     
         31 . The method of  claim 1 , wherein the cutting insert body is formed from a cemented carbide, cermet, or hard metal alloy.  
     
     
         32 . The method of  claim 31 , wherein the cutting insert body is formed of a cemented carbide comprising WC and Co, the cemented carbide comprising 10-20 weight % Co.  
     
     
         33 . The method of  claim 1 , wherein the cutting insert body is provided in the form of a polygon, oval or circle.  
     
     
         34 . The method of  claim 1 , wherein the cutting insert is provided in the form of a polygon.  
     
     
         35 . The method of  claim 1 , wherein the cavities are provided with a geometry that is complimentary to the geometry of the cutting tips received therein.  
     
     
         36 . The method of  claim 1 , further comprising applying at least one coating to at least a portion of the cutting tip and/or cutting insert body.  
     
     
         37 . The method of  claim 1 , further comprising forming a chip-breaker structure on the cutting insert body.  
     
     
         38 . The method of  claim 1 , comprising forming the cutting insert body in the shape of a polygon, and providing no more than 2 cavities therein.  
     
     
         39 . The method of  claim 1 , comprising forming the cutting insert body in the shape of a polygon, and providing no more than 4 cavities therein.  
     
     
         40 . A cutting insert comprising: 
 a cutting insert body having a plurality of cavities formed therein;    a plurality of cutting tips, each of the plurality of cutting tips disposed in a respective cavity, the cutting tips having a geometry that provides a mechanical retention or lock when inserted into the cavities of the cutting insert body said geometry including a generally trapezoidal anchor portion with its base substantially flat and spaced away from the cutting edge of the body and further comprising a braze joint between each of the cutting tips and the cutting insert body.    
     
     
         41 . The cutting insert of  claim 40 , wherein each of the cutting tips comprises, at least in part, a superhard cutting material.  
     
     
         42 . The cutting insert of  claim 41 , wherein each of the cutting tips are entirely made of a superhard cutting material.  
     
     
         43 . The cutting insert of  claim 41 , wherein the superhard material comprises cubic boron nitride or polycrystalline diamond.  
     
     
         44 . The cutting insert of  claim 43 , wherein the superhard material further comprises at least one of a nitride, carbonitride, oxide or boride of a metal chosen from groups IVa-VIa of the Periodic Table.  
     
     
         45 . The cutting insert of  claim 40 , wherein the superhard material comprises a composite having a first phase comprising cubic boron nitride or polycrystalline diamond particles and a second phase comprising a metal, a metalloid, or alloys thereof.  
     
     
         46 . The cutting insert of  claim 40 , wherein the cutting tip comprises a top surface and an opposing bottom surface, and the superhard material extends from the top surface to the bottom surface thereby defining two cutting edges.  
     
     
         47 . The cutting insert of  claim 40 , wherein the cutting tips have a general dovetail shape.  
     
     
         48 . The cutting insert of  claim 47 , wherein the cutting tip comprises a rounded forward nose and a pair of converging forward surfaces that meet at the nose.  
     
     
         49 . The cutting insert of  claim 48 , wherein at least the rounded forward nose portion of the cutting tip comprises the superhard material.  
     
     
         50 . The cutting insert of  claim 49 , wherein the superhard material is provided with a leg length of at least 2 mm, the leg length being defined as distance between a first point on one of the converging forward surfaces where the superhard material is connected to the substrate material, and a second point defined by the point of intersection between two imaginary lines drawn along each of the converging forward surfaces.  
     
     
         51 . The cutting insert of  claim 50 , wherein the leg length is at least 3 mm.  
     
     
         52 . The cutting insert of  claim 48 , wherein the cutting tip is provided with a waisted section of reduced width.  
     
     
         53 . The cutting insert of  claim 52 , wherein the waisted section comprises a first pair of angles surfaces and a second pair of surfaces that meet at the section of reduced width.  
     
     
         54 . The cutting insert of  claim 51 , wherein the length of one surface of said second pair of surfaces is different from the other of said surfaces.  
     
     
         55 . The cutting insert of  claim 40 , wherein the base of each of the cutting tips has a length different from the length of the base of the other of the cutting tips.  
     
     
         56 . The cutting insert of  claim 40 , wherein the cutting insert body is formed from a cemented carbide, cermet, or hard metal alloy.  
     
     
         57 . The cutting insert of  claim 56 , wherein the cutting insert body is formed of a cemented carbide comprising WC and Co, the cemented carbide comprising 10-20 weight % Co.  
     
     
         58 . The cutting insert of  claim 40 , wherein the cutting insert body is in the shape of a polygon, an oval or a circle.  
     
     
         59 . The cutting insert of  claim 58 , wherein the cutting insert body is in the shape of a polygon.  
     
     
         60 . The cutting insert of  claim 40 , wherein the cavities have a shape that is complimentary to the shape of the cutting tips.  
     
     
         61 . The cutting insert of  claim 40 , wherein at least one of the cutting tips and cutting insert body comprises a coating disposed on at least a portion thereof.  
     
     
         62 . The cutting insert of  claim 40 , wherein the cutting insert body comprises a chip-breaker structure.  
     
     
         63 . The cutting insert of  claim 40 , wherein the cutting insert comprises no more than 2 cutting tips.  
     
     
         64 . The cutting insert of  claim 40 , wherein the cutting insert comprises no more than 4 cutting tips.  
     
     
         65 . The cutting insert of  claim 40 , wherein the cutting tip is arranged symmetrically about a bisector through a corner of the insert.  
     
     
         66 . The cutting insert of  claim 40  wherein the cutting tip is arranged asymmetrically about a bisector through a corner of the insert.  
     
     
         67 . The cutting insert of  claim 40  wherein the cutting insert is a turning insert.  
     
     
         68 . The cutting insert of  claim 40  wherein the cutting insert is disposed on a drill.  
     
     
         69 . The cutting insert of  claim 68  wherein the cutting insert is disposed substantially parallel to the central axis of the drill.  
     
     
         70 . The cutting insert of  claim 68  wherein the cutting insert is disposed substantially perpendicular to the central axis of the drill.