A super hard polycrystalline construction is disclosed as comprising a first region comprising a body of thermally stable polycrystalline diamond material comprising a plurality of intergrown grains of diamond material; a second region forming a substrate to the first region; and a third region interposed between the first and second regions. The third region extends across a surface of the second region along an interface. The interface comprises at least a portion having an uneven topology, and the third region comprises a diamond composite material including a first phase comprising a plurality of non-intergrown super hard grains, said super hard grains comprising diamond grains; and a matrix material. The superhard material and matrix material of the third region form a diamond composite material which is more acid resistant than polycrystalline diamond material having a binder-catalyst phase comprising cobalt, and/or more acid resistant than cemented tungsten carbide material.

A super hard polycrystalline construction has a first region comprising a body of thermally stable polycrystalline super hard material having an exposed surface forming a working surface, and a peripheral side edge, said polycrystalline super hard material comprising a plurality of intergrown grains of super hard material; a second region forming a substrate to the first region; and a third region interposed between the first and second regions. The third region extends across a surface of the second region along an interface, the interface comprising at least a portion having an uneven topology, the third region comprising a composite material having a first phase comprising a plurality of non-intergrown grains of super hard material, and a matrix material, the third region having a wear resistance at least three times less than sintered polycrystalline diamond material having the same average grain size of diamond grains as the super hard grains in the third region.

A polycrystalline super hard construction is disclosed having a first region comprising a body of thermally stable polycrystalline super hard material having an exposed surface forming a working surface, and a peripheral side edge, the polycrystalline super hard material comprising a plurality of grains of super hard material; a second region forming a substrate to the first region; and a third region interposed between the first and second regions. The third region extends across a surface of the second region along an interface, the interface comprising a portion having an uneven topology and a substantially planar portion, the third region comprising a composite material including a first phase comprising a plurality of non-intergrown diamond grains, and a matrix material.

An embodiment of a PCD insert comprises an embodiment of a PCD element joined to a cemented carbide substrate at an interface. The PCD element has internal diamond surfaces defining interstices between them. The PCD element comprises a masked or passivated region and an unmasked or unpassivated region, the unmasked or unpassivated region defining a boundary with the substrate, the boundary being the interface. At least some of the internal diamond surfaces of the masked or passivated region contact a mask or passivation medium, and some or all of the interstices of the masked or passivated region and of the unmasked or unpassivated region are at least partially filled with an infiltrant material.

A PCD body comprises a skeletal mass of inter-bonded diamond grains defining interstices between them. At least some of the interstices contain a filler material comprising a metal catalyst material for diamond, the filler material containing Ti, W and an additional element M selected from the group consisting of V, Y, Nb, Hf, Mo, Ta, Zr Cr, Zr and the rare earth elements. The content of Ti within the filler material is at least 0.1 weight % and at most 20 weight %. The content of M within the filler material is at least 0.1 weight % and at most 20 weight %, and the content of W within the filler material is at least 5 weight % and at most 50 weight % of the filler material.

A polycrystalline super hard construction comprises a body of polycrystalline super hard material and a substrate bonded to the body along an interface. The substrate a first end surface forming the interface, the first end surface comprising a projection extending from the body of the substrate into the body of super hard material towards the cutting face, the body of polycrystalline material extending around the projection. The body of polycrystalline material comprises a first region more thermally stable than a second region, the first region comprising an annular portion located around the projection, the second region extending between and bonding the first region to the substrate. The first region has a thickness from the cutting face along the peripheral side edge to the interface of at least around 3 mm and a portion of the projection has a thickness measured in a plane extending along the longitudinal axis of at least around 3 mm.

The present invention relates to a polycrystalline diamond compact cutter with a low cobalt content cemented tungsten carbide substrate having a coating covering at least a portion of the carbide substrate and the method of making the same. The carbide substrate has a content of three to ten percent by weight on average of cobalt or its alloy as a binder. The coating covers at least partially the exterior surfaces of the carbide substrate, and it may extend over partially or entirely the polycrystalline diamond table. The coating is either a single layer or multilayer. The coating comprises at least a metallic layer. The coating has a thickness of 0.1 m-100 m. The coating may have a metallurgical bonding with the polycrystalline diamond compact cutter. Methods for preparing such coating comprise physical vapor deposition, chemical vapor deposition, thermoreactive deposition and diffusion, electrical plating, electroless plating, or their combinations.

Embodiments relate to polycrystalline diamond compacts (PDCs) that are less susceptible to liquid metal embrittlement damage due to the use of at least one transition layer between a polycrystalline diamond (PCD) layer and a substrate. In an embodiment, a PDC includes a PCD layer, a cemented carbide substrate, and at least one transition layer bonded to the substrate and the PCD layer. The at least one transition layer is formulated with a coefficient of thermal expansion (CTE) that is less than a CTE of the substrate and greater than a CTE of the PCD layer. At least a portion of the PCD layer includes diamond grains defining interstitial regions and a metal-solvent catalyst occupying at least a portion of the interstitial regions. The diamond grains and the catalyst collectively exhibit a coercivity of about 115 Oersteds or more and a specific magnetic saturation of about 15 Gauss.Math.cm.sup.3/grams or less.

A polycrystalline diamond compact including a cemented carbide substrate and a polycrystalline diamond layer bonded to the cemented carbide substrate. The cemented carbide substrate is cylindrical and includes a circumferential wall. The polycrystalline diamond layer includes a central part including between 8 and 15 wt. % of cobalt and an outer part including between 0.5 and 2 wt. % of cobalt. The outer part is a columnar ring belt and includes a chamfer. The outer part includes an upper surface, a side surface connected to the circumferential wall of the cemented carbide substrate, and a chamfer surface connecting the upper surface and the side surface. The chamfer includes a first terminal connected to the upper surface of the outer part and a second terminal connected to the side surface of the outer part.

A milling device is rotatable in one direction around a longitudinal center axis defining a forward direction and an opposite rearward direction, and includes a front part and a rear part. The front part has cutting edges, each having a longitudinal extension, and chip flutes, each having a longitudinal extension. The front part is made of a monolithic piece of ceramic. The rear part is configured to be fixed in a rotatable tool body or a rotatable chuck. The rear part is also made of a monolithic piece of cemented carbide. A front end surface of the rear part has a smaller area than a rear end surface of the front part. The front end surface of the rear part and a rear end surface of the front part are permanently bonded or brazed to each other by a joint.