Doubled-sided and multi-layered PCBN and PCD abrasive articles

Abstract

A doubled-sided PCBN and/or PCD compact can be produced using high pressure high temperature processes allowing for increased effective thickness of abrasive tools, decreased delamination, and increased useful service life. A polycrystalline compact can include a substrate having a first surface and a second surface which are non-contiguous. Additionally, a first polycrystalline layer can be attached to the first surface of the substrate and a second polycrystalline layer attached to the second surface of the substrate. The first and second polycrystalline layers can be attached to the substrate via an intermediate layer containing superabrasive particles. Such double-sided PCBN and PCD compacts allow for increased effective thickness of a tool without suffering from non-homogenous results typical of standard PCD and PCBN compacts, regardless of superabrasive particle size. Each polycrystalline layer can include superabrasive particles of varying particle sizes such that the final tool is tailored for specific abrading characteristics. Such doubled-sided PCBN and PCD compacts can be incorporated into a wide variety of abrasive tools for use in cutting, milling, grinding, polishing, drilling and other similar abrasive applications.

1 . A polycrystalline compact, comprising: 
 a) a metal substrate having a first surface and a second surface, wherein the first and second surfaces are non-contiguous;    b) a first polycrystalline layer attached to the first surface using a first intermediate layer, said first polycrystalline layer including first superabrasive particles bonded together and said first intermediate layer including a consolidated mixture of first intermediate superabrasive particles and a first binder metal; and    c) a second polycrystalline layer attached to the second surface using a second intermediate layer, said second polycrystalline layer including second superabrasive particles bonded together and said second intermediate layer including a consolidated mixture of second intermediate superabrasive particles and a second binder metal.    
     
     
         2 . The polycrystalline compact of  claim 1 , wherein the first and second intermediate superabrasive particles are a mixture of diamond and cubic boron nitride particles.  
     
     
         3 . The polycrystalline compact of  claim 2 , wherein first and second polycrystalline layers are polycrystalline cubic boron nitride and the volume ratio of diamond to cubic boron nitride particles is from about 0.0005:1 to about 0.05:1 .  
     
     
         4 . The polycrystalline compact of  claim 1 , wherein the first and second intermediate layers each comprise from about 50 to about 99 vol % superabrasive particles.  
     
     
         5 . The polycrystalline compact of  claim 1 , wherein the first and second binder metals are a member selected from the group consisting of Co, WC, Al, Ti, Ni, and alloys thereof.  
     
     
         6 . The polycrystalline compact of  claim 1 , wherein the first and second intermediate layers comprise from about 5 vol % to about 25 vol % binder metal.  
     
     
         7 . The polycrystalline compact of  claim 1 , wherein the first and second binder metal have an average particle size which is smaller than an average particle size of the first and second intermediate superabrasive particles, respectively.  
     
     
         8 . The polycrystalline compact of  claim 1 , wherein the first and second intermediate layers further include a first and second bonding medium, respectively, and are each a member selected from the group consisting of TiC, TiN, TiCN, AIN, TiB 2 , SiO 2 , Si 3 N 4 , and combinations thereof.  
     
     
         9 . The polycrystalline compact of  claim 8 , wherein the first and second intermediate layers comprise from about 5 vol % to about 25 vol % bonding medium.  
     
     
         10 . The polycrystalline compact of  claim 1 , wherein at least one interface is contoured having a plurality of features, said at least one interface being a first polycrystalline layer-first intermediate layer interface, a second polycrystalline layer-second intermediate layer interface, a first intermediate layer-first surface interface, or a second intermediate layer-second surface interface.  
     
     
         11 . The polycrystalline compact of  claim 9 , wherein the plurality of features are pyramids.  
     
     
         12 . The polycrystalline compact of  claim 9 , wherein a surface area of the at least one interface is from about 1.2 to about 2 cm 2  per cm 2  of non-contoured area.  
     
     
         13 . The polycrystalline compact of  claim 9 , wherein the plurality of features are present at a concentration of from about 50 to about 300 features per cm 2 .  
     
     
         14 . The polycrystalline compact of  claim 1 , wherein the first and second intermediate superabrasive particles have a ratio of largest to smallest particles which is from about 1 to about 500.  
     
     
         15 . The polycrystalline compact of  claim 1 , wherein the first and second superabrasive particles have different average particles sizes.  
     
     
         16 . The polycrystalline compact of  claim 1 , wherein the first and second superabrasive particles have a ratio of largest to smallest particles which is from about 1 to about 10.  
     
     
         17 . The polycrystalline compact of  claim 1 , wherein the first and second intermediate layers have a thickness from about 0.2 to about 0.7 times a thickness of the first and second polycrystalline layers, respectively.  
     
     
         18 . A polycrystalline tool formed from the polycrystalline compact of  claim 1 , wherein the polycrystalline tool is a member selected from the group consisting of drill bit, cutting insert, wire drawing die, and saw blade.  
     
     
         19 . A method of forming a polycrystalline compact, comprising steps of: 
 a) forming a first superabrasive layer in a reaction assembly, said first superabrasive layer including first superabrasive particles and an optional first binder metal;    b) forming a first intermediate layer adjacent the first superabrasive layer, said first intermediate layer including a mixture of first intermediate superabrasive particles and a first binder metal;    c) forming a metal substrate layer adjacent the first intermediate layer;    d) forming a second intermediate superabrasive layer opposite the first intermediate layer, said second intermediate layer including a mixture of intermediate second superabrasive particles and a second binder metal;    e) forming a second superabrasive layer adjacent the second intermediate layer, said second superabrasive layer including second superabrasive particles and an optional second binder metal; and    f) heating said first and second superabrasive layers such that superabrasive particles of each layer are bonded together to form a multilayer polycrystalline compact.    
     
     
         20 . The method of  claim 19 , wherein the substrate is a fully sintered, partially sintered, or unsintered preform mass.  
     
     
         21 . The method of  claim 19 , wherein the first and second intermediate superabrasive particles are a mixture of diamond and cubic boron nitride particles.  
     
     
         22 . The method of  claim 21 , wherein first and second polycrystalline layers are polycrystalline cubic boron nitride and the volume ratio of diamond to cubic boron nitride particles is from about 0.05:1 to about 1:1.  
     
     
         23 . The method of  claim 19 , wherein the first and second intermediate layers each comprise from about 50 to about 99 vol % superabrasive particles.  
     
     
         24 . The method of  claim 19 , wherein the first and second intermediate layers comprise from about 5 vol % to about 25 vol % binder metal.  
     
     
         25 . The method of  claim 19 , wherein the first and second intermediate layers further comprise from about 5 vol % to about 25 vol % of a bonding medium.  
     
     
         26 . The method of  claim 19 , further comprising the step of stamping a surface of at least one of said layers with a pattern of features.  
     
     
         27 . The method of  claim 26 , wherein the plurality of features are pyramids.  
     
     
         28 . The method of  claim 26 , wherein every interface between differing layers is stamped with the pattern of features.  
     
     
         29 . The method of  claim 19 , wherein the first and second superabrasive particles have different average particles sizes.  
     
     
         30 . The method of  claim 19 , further comprising the step of cutting the polycrystalline compact such that a plurality of polycrystalline tool inserts are formed having at least two polycrystalline surfaces.  
     
     
         31 . The method of  claim 30 , further comprising the step of attaching at least one of the plurality of polycrystalline tool inserts to a tool body, wherein at least a portion of the substrate is attached to the tool body.  
     
     
         32 . The method of  claim 30 , further comprising the step of attaching at least one of the plurality of polycrystalline tool inserts to a tool body, wherein only one of the first and second polycrystalline layers is attached to the tool body.