Iron gradient in polycrystalline diamond compacts; blanks, cutters and cutting tools including same; and methods of manufacture
Polycrystalline diamond compacts, polycrystalline diamond blanks, polycrystalline diamond cutters, and tools incorporating same for cutting, milling, grinding, drilling and other abrasive operations, particularly in metal cutting applications, include a diamond table having a gradient in iron content that increases as distance into the volume of the diamond table increases. The iron gradient increases resistance to wear, such as in interrupted milling tests. The disclosure further relates to methods of manufacturing polycrystalline diamond compacts having a gradient in iron concentration in the diamond table, blanks and cutters including polycrystalline diamond compacts, cutting tools incorporating such compacts, blanks and cutters, and methods of cutting, milling, grinding and drilling, particularly metal machining, using such compacts, blanks, cutters, cutting tools and drill bits.
1. A polycrystalline diamond compact, comprising: a volume of crystalline diamond grains bonded together by diamond-to-diamond bonds to form a diamond body, the diamond body including a plurality of inter-grain regions disposed between the bonded crystalline diamond grains; a cobalt-based catalyst material present in at least a portion of the plurality of inter-grain regions; and an iron concentration gradient extending from an exterior surface of the diamond body into an interior volume of the diamond body, wherein the iron concentration gradient varies from between about 0 wt. % to 0.01 wt % Fe at the exterior surface of the diamond body to 0.7 to 0.9 wt. % at a distance of 600 to 700 microns from the exterior surface of the diamond body.
2. The polycrystalline diamond compact according to claim 1 , wherein the iron concentration gradient varies linearly from the exterior surface of the diamond body into the interior volume of the diamond body.
3. The unsupported polycrystalline diamond compact according to claim 1 , wherein the crystalline diamond grains have an average grain size of 0.5 to 3 microns.
4. A polycrystalline diamond compact, comprising: a volume of crystalline diamond grains bonded together by diamond-to-diamond bonds to form a diamond body, the diamond body including a plurality of inter-grain regions disposed between the bonded crystalline diamond grains; a cobalt-based catalyst material present in at least a portion of the plurality of inter-grain regions; and an iron concentration gradient extending from an exterior surface of the diamond body into an interior volume of the diamond body, wherein the iron concentration gradient varies from between 0.01 to 0.1 wt. % Fe at the exterior surface of the diamond body to 0.7 to 0.9 wt. % at a distance of 600 to 700 microns from the exterior surface of the diamond body.
5. A polycrystalline diamond compact, comprising: a volume of crystalline diamond grains bonded together by diamond-to-diamond bonds to form a diamond body, the diamond body including a plurality of inter-grain regions disposed between the bonded crystalline diamond grains; a cobalt-based catalyst material present in at least a portion of the plurality of inter-grain regions; and an iron concentration gradient extending from an exterior surface of the diamond body into an interior volume of the diamond body, wherein the iron concentration gradient varies from between about 0 wt. % to 0.01 wt % Fe at the exterior surface of the diamond body to about 0.3 to 0.4 wt. % at a distance of 600 to 700 microns from the exterior surface of the diamond body.
6. The polycrystalline diamond compact according to claim 5 , wherein the crystalline diamond grains have an average grain size of 25 to 30 microns.
7. A polycrystalline diamond compact, comprising: a volume of crystalline diamond grains bonded together by diamond-to-diamond bonds to form a diamond body, the diamond body including a plurality of inter-grain regions disposed between the bonded crystalline diamond grains; a cobalt-based catalyst material present in at least a portion of the plurality of inter-grain regions; and an iron concentration gradient extending from an exterior surface of the diamond body into an interior volume of the diamond body, wherein the iron concentration gradient varies from between 0.01 to 0.1 wt. % Fe at the exterior surface of the diamond body to 0.3 to 0.4 wt. % at a distance of 600 to 700 microns from the exterior surface of the diamond body.
8. A polycrystalline diamond blank comprising the polycrystalline diamond compact according to claim 1 and a hard metal substrate, wherein the diamond body is bonded to the hard metal substrate to form an interface.
9. The polycrystalline diamond blank according to claim 8 , wherein the hard metal substrate has a composition including cemented carbide or cobalt sintered tungsten carbide (WC—Co).
10. The polycrystalline diamond blank according to claim 8 , wherein the hard metal substrate has a composition that is iron-free.
11. A metal cutting tool, comprising:
a metal alloy body including a front end, a shaft portion, and a rear end adapted to be mounted in a tool holder, wherein the front end, the shaft portion, and the rear end are arranged sequentially along a longitudinal axis of the body; and
a polycrystalline diamond compact according to claim 1 attached to the front end.