Patent Application
20130014998
Downhole cutting tools have a tendency to crack because they are manufactured from very high strength (and therefore brittle) materials. Further, during manufacture, these tools are often subjected to very high temperatures, such as to wet braze cutting material onto the tools, and extensive machining. These cracks limit the life of such tools, increasing material used, time spent replacing the tools, and overall costs. Additionally, these tools need to be closely inspected for cracks and sometimes repaired even before use, further increasing cost, time and materials. Improvements in downhole cutting tools are accordingly well received by the industry.
A downhole cutting tool includes a base including a first consolidated powder; and at least one cutting feature affixed to the base, the at least one cutting feature including a cutting material suspended in a second consolidated powder, wherein the base and the at least one cutting feature are both consolidated and bonded together simultaneously.
A method of manufacturing a cutting tool includes layering a first powder and a second powder in a die, the second powder comprising cutting material suspended therein; and simultaneously consolidating the first and second powders to form a base and at least one cutting feature, respectively, the simultaneous consolidating also bonding the base to the at least one cutting feature.
The following descriptions should not be considered limiting in any way. With reference to the accompanying drawings, like elements are numbered alike:
A detailed description of one or more embodiments of the disclosed apparatus and method are presented herein by way of exemplification and not limitation with reference to the Figures.
Referring now to
The base 12 (including the neck 18) and the cutting features 14 are both formed from consolidated or compacted powder material or matrixes. Processes contemplated herein for consolidating powdered materials include high velocity compaction and/or adiabatic processes, available by Utron of Manassas, Va.; Hydropulsor of Karlskoga, Sweden; and LMC of DeKalb, Ill. For example, in the high velocity or adiabatic process, a piston or ram is actuated at very high speed by igniting a gas such as argon. Other processes include field assisted sintering technology (FAST) or spark plasma sintering, in which an up to 300 ton force is applied to powder in a die while pulses of electrical current are passed through the powder to create extremely high localized temperatures between powdered particles. Another process is disclosed in U.S. Pat. No. 4,539,175, which patent is hereby incorporated by reference, in which a preform is first made by at least partially consolidating powder in a first die, moving the preform into a second die containing a bed of heated ceramic particles, and then compressing the particles to solidify the powder with a hydraulic ram or the like to full density or near full density.
In any of these processes, the powder is first layered in a die and then subjected to pressure, heat, etc. For example, a die 20 and a ram 22 is shown in
By layering the base material 12′ and the cutting feature material 14′ in the die 20, simultaneous consolidation is possible. Additionally and also simultaneously with the consolidation of the materials 12′ and 14′, the heat and/or pressure of the consolidation process bonds the cutting features 14 to the base 12. Advantageously, the need to perform a separate bonding operation is avoided by layering the two materials in the same die, saving time and manufacturing cost. Further, not having to perform a separate bonding operation avoids the cracking issues of prior systems because additional machining to the tool, such as to form watercourses, and the application of very high temperatures to the tool, such as to wet braze cutting material to the base of the tool at temperatures approaching 1900° F., can be avoided. Of course, one could grind or machine watercourses into the base 12 after consolidation, if desired, and this would still avoid the need for a separate bonding operation.
Although heat and pressure is applied to the tool 10, this heat and pressure is applied only to the powdered materials or matrixes and is required to consolidate the powders 12′ and 14′. In fact, when in powdered or matrix form, high temperatures can be desired for the creation of high density parts. Importantly, the heat is applied only during consolidation, not after the part is formed, such as prior cast tools that tend to crack from subsequent applications of heat. Additionally, the increased strength obtainable by simultaneously bonding and consolidating the components of the tool 10 avoids the need for welded support members, which were previously used and resulted in prior tools being subjected to even more heat. As a result, cracking will not readily occur according to the current invention, and instead, a single, bonded, and fully dense part is produced.
In one embodiment, the matrix 14′ that forms the cutting features 14 comprises a polymeric or metallic composition of, for example, nickel, copper, iron, cobalt, or some other material exhibiting suitable bonding and strength qualities, having an embedded cutting material therein, which is one or more hard particulate materials such as tungsten carbide, cubic boron nitride, diamond, silicon carbide and combinations including at least one of the foregoing and other similar materials mixed therein before the matrix is cured. The mixture in one embodiment will be homogenous while in other embodiments the cutting materials mixed into the matrix may be concentrated in certain areas to affect mechanical properties (strength, wear resistance, wear pattern, etc.) of the cutting features 14 of the cutting tool 10. One embodiment utilizes a matrix material that is proprietary to and commercially available from Protech Centerform Inc, Houston, Tex. In one embodiment, the base material 12′ is a powdered steel such that the base 12 can be welded or threaded onto a shoe casing or the like.
While the invention has been described with reference to an exemplary embodiment or embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof Therefore, it is intended that the invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the claims. Also, in the drawings and the description, there have been disclosed exemplary embodiments of the invention and, although specific terms may have been employed, they are unless otherwise stated used in a generic and descriptive sense only and not for purposes of limitation, the scope of the invention therefore not being so limited. Moreover, the use of the terms first, second, etc. do not denote any order or importance, but rather the terms first, second, etc. are used to distinguish one element from another. Furthermore, the use of the terms a, an, etc. do not denote a limitation of quantity, but rather denote the presence of at least one of the referenced item.
