Sacrificial Catalyst Polycrystalline Diamond Element

Abstract

A superhard composite material comprising a polycrystalline diamond cutter (PDC) having a cutting surface and cutting edges having a polycrystalline diamond thickness of about 3 mm is integrally formed with a sacrificial catalyst source that is removed later in the processing of the of the cutter.

Description

BACKGROUND OF THE INVENTION[0001]1. Field of the Invention[0002]Disclosed herein are elements of superhard polycrystalline material synthesized in a high-temperature, high-pressure process and used for wear, cutting, drawing, and other applications. These elements have specifically placed superhard surfaces at locations where wear resistance is required. In particular, these elements are polycrystalline diamond and polycrystalline diamond-like (collectively called PCD) elements with tailored wear and impact resistance and methods of manufacturing them.[0003]2. Description of the Related Art[0004]U.S. Pat. No. 4,534,773 discloses a method of producing an abrasive body of diamond particles in diamond-to-diamond bond with second phase of Ni and / or Si under condition of a High Temperature, High Pressure (HPHT) apparatus.[0005]U.S. Pat. No. 6,861,098 discloses known methods for fabrication of PDC cutter, inserts and tools. Polycrystalline diamond and polycrystalline diamond-like elements...

AI Technical Summary

Benefits of technology

[0015]A super hard material composite is described which has an in-situ formed PCD complex face optimized for aggressive cutting of formation, low contamination levels in the PCD working surface, and an integrally bonded substrate that can be optimized for wear and impact strength. The composite material has a plurality of hard-phase (Diamond, CBN) particles integrally bonded to plurality of catalyst-free (W, Mo, V, etc) C particles via temperature and pressure. Sintering and densification of the composite layer is aided by catalyst which may be one or more of Co, Ni, and Fe. These elements may be released from a sacrificial substrate that is removed by mechanical or chemical methods after composite manufacture.

[0016]The resultant composite may have features including: a premixed or mechanically blended diamond / metallic interface to reduce residual stress, a PCD surface that is the negative of the substrate, and low residual contamination in the diamond and metal carbide particles to be moved to the bottom of the post-sintered PCD substrate. The catalyst flow (sweep) occurs through the diamond layer, causing a physical action that in essence mechanically bonds and blends the interface layer and substrate particle bed during processing. The catalyst sweeps from the substrate toward the sacrificial substrate, thus pushing the impurities toward the PCD layer / sacrificial substrate interface and allowing much of the impurities to be removed while sacrificial substrate is removed.

[0019]EB or vacuum brazed sealing of can / container may be used to lower contamination levels prior to HTHP sintering to inhibit impurity migration to the PCD surface.

Problems solved by technology

A common trait of PCD elements is the use of catalyzing materials during their formation, the residue from which, often imposes a limit upon the maximum useful operating temperature of the element while in service.

The assembly is then subjected to very high temperature and pressure in a press.

Although not described in detail, in the method used to form the protrusion on the PCD, it is assumed that the surface texture and geometry in this case is limited to its ability to extrude / form can surfaces that are a negative of the desired PCD front face extrusions; alternatively post HTHP processing such as EDM and Laser cutting may be necessary to form these surfaces on the cutter face.

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