Cubic boron nitride compact

Abstract

A CBN compact which contains CBN and a matrix phase, wherein the CBN grain size volume frequency distribution has a distribution spread expressed as d90-d10 of 1 micron or greater, and the d90 maximum value is 5 micron or less.

1 - 16 . (canceled) 
     
     
         17 . A CBN compact which comprises CBN and a matrix phase, wherein the CBN grain size volume frequency distribution has a distribution spread expressed as d90-d10 of 1 micron or greater, and the d90 maximum value is 5 micron or less. 
     
     
         18 . A CBN compact according to  claim 17 , wherein the d90 maximum value is 3.5 micron or less. 
     
     
         19 . A CBN compact according to  claim 18 , wherein the d90 maximum value is 2.5 micron or less. 
     
     
         20 . A CBN compact according to  claim 17 , wherein the matrix phase comprises a secondary hard phase including a compound containing a nitride or carbonitride of a Group 4, 5 or 6 transition metal or a mixture or solid solution thereof. 
     
     
         21 . A CBN compact according to  claim 20 , wherein the Group 4, 5 or 6 transition metal is titanium. 
     
     
         22 . A CBN compact according to  claim 20 , wherein the matrix phase further comprises a binder phase consisting of aluminum and optionally one or more of other elements chosen from silicon, iron, nickel, cobalt, titanium, tungsten, niobium and molybdenum, which one or more other elements is alloyed, compounded or formed in solid solution with the aluminum. 
     
     
         23 . A tool insert comprising a CBN compact according to  claim 17 . 
     
     
         24 - 27 . (canceled)