Molten braze-coated superabrasive particles and associated methods

Abstract

A superabrasive particle coated with a solidified coating of a molten braze alloy that is chemically bonded to the superabrasive particle, where the molten braze alloy includes a substantially less-reactive protective material, is disclosed and described. In one aspect, the molten braze alloy may coat at least about 80% of an outer surface of the superabrasive particle. Various methods for making and using such a coated superabrasive particle are additionally disclosed and described.

Description

PRIORITY DATA [0001] This application is a continuation-in-part of U.S. patent application Ser. No. 10 / 627,441, filed Jul. 25, 2003, which is a continuation-in-part of U.S. patent application Ser. No. 10 / 254,057, filed Sep. 24, 2002, each of which is incorporated herein by reference.FIELD OF THE INVENTION [0002] The present invention relates to devices that incorporate superabrasive materials, and methods for the production and use thereof. Accordingly, the present invention involves the fields of chemistry, physics, and materials science. BACKGROUND OF THE INVENTION [0003] A variety of abrasive and superabrasive tools have been developed over the past century for performing the general function of removing material from a workpiece. Actions such as sawing, drilling, polishing, cleaning, carving, and grinding, are all examples of material removal processes that have become fundamental to a variety of industries. [0004] A number of specific material removal applications require the u...

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Benefits of technology

[0011] Accordingly, the present invention provides superabrasive tools having improved superabrasive particle retention, and methods for the making thereof. Furthermore, a method is provided for preserving the strength of a superabrasive particle having a braze alloy coating bonded thereto by application of the braze alloy coating in a molten state. In one aspect, such a method may include the step of protecting the superabrasive particle with a protective material that is substantially less-reactive with the superabrasive particle during application of the braze alloy coating to the superabrasive particle.

[0012] Another embodiment of the present invention provides a method for coating a superabrasive particle having improved strength, a braze alloy coating being bonded to the particle by application of the braze alloy coating in a molten state. In one aspect, the method may include the steps of providing a superabrasive particle, protecting the superabrasive particle as recited herein while coating the superabrasive particle with a molten braze alloy, and allowing the coating to solidify.

[0015] The present invention additionally provides a coated superabrasive particle having improved retention properties when incorporated into a tool. As such, one embodiment of the present invention provides a superabrasive tool precursor including at least one superabrasive particle bonded with a braze alloy coating, the braze alloy coating including a substantially less-reactive protective material, where the braze alloy coating including the substantially less-reactive protective material provides improved strength to the coated superabrasive particle as compared with the braze alloy alone.

[0017] In yet another embodiment of the present invention, a superabrasive tool is provided that may include a plurality of superabrasive particles bonded together with a braze alloy coating, the braze alloy coating including a substantially less-reactive protective material, where the braze alloy coating including the substantially less-reactive protective material provide improved strength to the coated superabrasive particle as compared with the braze alloy alone, and a plurality of spacer particles chemically bonded to the molten braze alloy.

Problems solved by technology

In these cases, the use of conventional abrasive tools may be infeasible due to the nature of the workpiece, or the surrounding circumstances of the process.

For example, activities such as cutting stone, tile, cement, etc., are often cost prohibitive, if not impossible to accomplish, when attempted using a conventional metal saw blade.

However, because the matrix surrounding the superabrasive particles is softer than the superabrasive particles, it wears away more quickly during use, and leaves the diamond particles overexposed, and unsupported.

As a result, the diamond particles become prematurely dislodged and shorten the service life of the tool.

However, such processes are difficult and costly for a variety of reasons, including the highly inert nature of most superabrasive particles, and the high melting point of most reactive materials.

Moreover, while chemically bonding the superabrasive particle to the matrix material via carbide bonds creates a much stronger relationship between the superabrasive and the matrix material, the carbide materials formed are not as strong as the superabrasive materials, thus decreasing its integrity.

To this end, the method by which the reactive material may be applied to the superabrasives is generally limited to either solid-state reactions or gas reactions that are carried out at a temperature that is sufficiently low so that damage to the diamond does not occur.

Such processes are only capable of achieving a monolithic coating, and cannot produce an alloy coating.

While the strength of the carbide bonds yielded using these techniques generally improves particle retention over mere mechanical bonds, they still allow superabrasive particles to become dislodged prematurely.

While such processes may yield a tool that has greater grit retention than tools having no chemical bonding of the superabrasive particles, as a general matter, solid-state sintering of the braze alloy only consolidates the matrix material, and does not attain as much chemical bonding as the solid and gas state deposition techniques.

Additionally, the use of conventional braze may be limited, as it generally also serves as the matrix material for the body of the tool.

Most braze alloys are ill equipped to act as a bonding medium and simultaneously act as the matrix material, due to the specific characteristics required by each of these elements during use.

A matrix that is made of a material that is too soft may wear away too quickly and allow the superabrasive particles to dislodge prematurely.

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