Disclosed is a polycrystalline diamond or diamond-like element with greatly improved wear resistance without loss of impact strength. These elements are formed with a binder-catalyzing material in a high-temperature, high-pressure (HTHP) process. The PCD element has a body with a plurality of bonded diamond or diamond-like crystals forming a continuous diamond matrix that has a diamond volume density greater than 85%. Interstices among the diamond crystals form a continuous interstitial matrix containing a catalyzing material. The diamond matrix table is formed and integrally bonded with a metallic substrate containing the catalyzing material during the HTHP process. The diamond matrix body has a working surface, where a portion of the interstitial matrix in the body adjacent to the working surface is substantially free of the catalyzing material, and the remaining interstitial matrix contains the catalyzing material. Typically, less than about 70% of the body of the diamond matrix table is free of the catalyzing material.

High volume density polycrystalline diamond with working surfaces depleted of catalyzing material

A preform cutting element for a rotary drill bit includes a layer of polycrystalline diamond material, the rear face of which is bonded to the front face of a backing layer of less hard material, such as tungsten carbide. The rear face of the backing layer is substantially greater in area than the rear face of the diamond layer. A method of manufacturing such cutting elements comprises forming an intermediate structure comprising polycrystalline diamond material bonded between two outer layers of tungsten carbide, and then cutting the intermediate structure to provide two pieces, each of the pieces including part of the diamond material and at least a major part of a respective one of the two outer layers.

Cutting elements for rotary drill bits

The present invention provides a superhard polycrystalline diamond or diamond-like element with greatly improved resistance to thermal degradation without loss of impact strength. Collectively called PCD elements, these elements are formed with a binder-catalyzing material in a high-temperature, high-pressure process. The PCD element has a plurality of partially bonded diamond or diamond-like crystals forming at least one continuous diamond matrix, and the interstices among the diamond crystals forming at least one continuous interstitial matrix containing a catalyzing material. The element has a working surface and a body, where a portion of the interstitial matrix in the body adjacent to the working surface is substantially free of the catalyzing material, and the remaining interstitial matrix contains the catalyzing material. This translates to higher wear resistance in cutting applications, higher heat transfer capacity in heat sink applications, and has advantages in numerous other applications including hollow dies, indentors, tool mandrels, and wear elements.

Polycrystalline diamond partially depleted of catalyzing material

Thermally stable diamond constructions comprise a diamond body having a plurality of bonded diamond crystals and a plurality of interstitial regions disposed among the crystals. A metallic substrate is attached to the diamond body. A working surface is positioned along an outside portion of the diamond body, and the diamond body comprises a first region that is substantially free of a catalyst material, and a second region that includes the catalyst material. The diamond body first region extends from the working surface to depth of at least about 0.02 mm to a depth of less than about 0.09 mm. The diamond body includes diamond crystals having an average diamond grain size of greater than about 0.02 mm, and comprises at least 85 percent by volume diamond based on the total volume of the diamond body.

Thermally stable diamond polycrystalline diamond constructions

Thermally stable ultra-hard compact constructions of this invention comprise an ultra-hard material body that includes a thermally stable region positioned adjacent a surface of the body. The thermally stable region is formed from consolidated materials that are thermally stable at temperatures greater than about 750° C. The thermally stable region can occupy a partial portion of or the entire ultra-hard material body. The ultra-hard material body can comprise a composite of separate ultra-hard material elements that each form different regions of the body, at least one of the regions being thermally stable. The ultra-hard material body is attached to a desired substrate, an intermediate material is interposed between the body and the substrate, and the intermediate material joins the substrate and body together by high pressure/high temperature process.

Thermally stable ultra-hard material compact constructions

A sintered polycrystalline diamond compact having an integral metallic heat sink bonded to and covering at least the outer diamond surface is used to increase compact life when the compact is used for material removal without a fluid coolant.

Sintered polycrystalline diamond compact construction with integral heat sink

Abrasive particles are prepared by milling cubic boron nitride particles, metal compound and milling balls to smear a coating of the compound on the cubic boron nitride particles and firing the compound-coated boron nitride particles producing a rough granular adherent covering of metal and/or metal boride and/or nitride surface coating chemically bonded to the cubic boron nitride surface by metal boride and/or nitride.

Modifying the surface of cubic boron nitride particles

The coulometric determination of sulfur in silicon-iron

For shear-cutting a stack of thin sheets of amorphous steel along a cutting plane that extends transversely of the stack, we utilize apparatus that comprises two blades that are positioned at the start of a cutting operation on opposite sides of the stack. Each of the blades has a first surface for engaging one side of the stack and a second surface extending transversely of the first surface and generally parallel to said cutting plane and intersecting the first surface at a corner. The first surface of each blade is disposed at a predetermined rake angle with respect to a reference plane extending through a point on the corner of the blade and normal to said cutting plane. By making the sum of these rake angles of a negative value and beween 5 and 35 degrees, we are able to substantially improve the wear resistance of the blades and lengthen their working life.

Louis E. Hibbs

Papers

Sintered polycrystalline diamond compact construction with integral heat sink

Modifying the surface of cubic boron nitride particles

The coulometric determination of sulfur in silicon-iron

Apparatus for shear-cutting a stack of amorphous steel sheets

The determination of cobalt, iron plus vanadium or manganese in soft magnetic alloys