Doubled-sided and multi-layered PCBN and PCD abrasive articles

Abstract

A doubled-sided PCBN and / or PCD compact can be produced using high pressure high temperature processes allowing for increased effective thickness of abrasive tools, decreased delamination, and increased useful service life. A polycrystalline compact can include a substrate having a first surface and a second surface which are non-contiguous. Additionally, a first polycrystalline layer can be attached to the first surface of the substrate and a second polycrystalline layer attached to the second surface of the substrate. The first and second polycrystalline layers can be attached to the substrate via an intermediate layer containing superabrasive particles. Such double-sided PCBN and PCD compacts allow for increased effective thickness of a tool without suffering from non-homogenous results typical of standard PCD and PCBN compacts, regardless of superabrasive particle size. Each polycrystalline layer can include superabrasive particles of varying particle sizes such that the final tool is tailored for specific abrading characteristics. Such doubled-sided PCBN and PCD compacts can be incorporated into a wide variety of abrasive tools for use in cutting, milling, grinding, polishing, drilling and other similar abrasive applications.

Description

RELATED APPLICATIONS [0001] This application is a continuation-in-part of U.S. patent application Ser. No. 10 / 655,758, filed Sep. 5, 2003, which is hereby incorporated by reference in its entirety.FIELD OF THE INVENTION [0002] The present invention relates generally to abrasive tools and methods for producing such abrasive tools. Specifically, the present invention relates to high pressure high temperature polycrystalline diamond and polycrystalline cubic boron nitride articles and methods for producing these polycrystalline articles. Accordingly, the present application involves the fields of physics, chemistry, and material science. BACKGROUND OF THE INVENTION [0003] Polycrystalline diamond (PCD) and polycrystalline cubic boron nitride (PCBN) compacts are used extensively in the superabrasive industry for the production of cutting tools, drill bits, wire drawing dies, dressers, and a wide variety of other tools. The basic process of forming PCD / PCBN compacts was developed in the 1...

AI Technical Summary

Benefits of technology

"The present invention provides new PCD and PCBN materials that have wider applications than existing materials. These materials have improved cutting and abrasive properties, including increased effective thickness and reduced delamination problems. The invention also provides methods for producing these materials using HPHT methods. The polycrystalline compacts can be used in various abrasive tools such as drill bits, cutting inserts, wire drawing dies, saw blades, wire saws, and other abrasive tools. The invention also includes a method of forming a multi-layered polycrystalline article by HPHT sintering. Overall, the invention provides new materials and methods for improved abrasive applications."

Problems solved by technology

However, the thickness of a typical PCD / PCBN layer is often limited to less than about 1 mm, although some methods can increase this thickness somewhat.

Thus, typical thick solid and layered polycrystalline materials have certain limits to the available grain sizes for particular thicknesses.

Further, the non-homogenous sintering of the compacts leaves interior volumes of the compact which are weaker due at least in part to poorly bonded microstructures than exterior portions.

As a result, the compact is prone to premature chipping and / or cracking during use, or even during high pressure high temperature (HPHT) sintering stages, thus reducing the useful life of any tool formed therewith.

However, these methods also tend to increase production costs and manufacturing complexity and still have limitations on the achievable thickness of the PCD.

Such a solid PCBN is not easily processed with finer powders and results in a limited grade of products and is further limited in utility since most non-solid products are produced for use in a wide range of applications having various grades of PCBN products.

In addition, typical PCBN and PCD compacts and tools can tend to have problems with delamination of the superabrasive layer from an underlying substrate.

This delamination is generally due to thermal expansion mismatch between the substrate and polycrystalline superabrasive layers.

Through repeated cycling of heating and cooling, the interface between the layers becomes weakened and fatigued due to thermal mismatch such that delamination occurs.

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