U.S. patent application number 15/378992 was filed with the patent office on 2017-03-30 for fiber-containing diamond-impregnated cutting tools and methods of forming and using same.
The applicant listed for this patent is LONGYEAR TM, INC.. Invention is credited to KRISTIAN S. DRIVDAHL, CHRISTIAN M. LAMBERT, CODY A. PEARCE, MICHAEL D. RUPP.
Application Number | 20170087693 15/378992 |
Document ID | / |
Family ID | 51350346 |
Filed Date | 2017-03-30 |
United States Patent
Application |
20170087693 |
Kind Code |
A1 |
DRIVDAHL; KRISTIAN S. ; et
al. |
March 30, 2017 |
FIBER-CONTAINING DIAMOND-IMPREGNATED CUTTING TOOLS AND METHODS OF
FORMING AND USING SAME
Abstract
Fibers for diamond-impregnated cutting tools and their
associated methods for manufacture and use are described. A matrix
is formed that contains fibers made from carbon, glass, ceramic,
polymer, and the like. The matrix is then sintered to form a
cutting portion of a drill bit. The type and concentration of the
fibers can be modified to control the tensile strength and the
erosion rate of the matrix to optimize the cutting performance of
the tools. Additionally, the fibers may be added to the cutting
section to weaken the structure and allow higher modulus binders to
be used for the cutting tools at a lower cost, allowing the amount
of fibers to be tailored to retain the diamonds in the cutting
portion for the desired amount. As the cutting portion erodes, the
fibers may also increase the lubricity at the face of the cutting
portion.
Inventors: |
DRIVDAHL; KRISTIAN S.; (Park
City, UT) ; RUPP; MICHAEL D.; (Murray, UT) ;
LAMBERT; CHRISTIAN M.; (Draper, UT) ; PEARCE; CODY
A.; (Midvale, UT) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
LONGYEAR TM, INC. |
Salt Lake City |
UT |
US |
|
|
Family ID: |
51350346 |
Appl. No.: |
15/378992 |
Filed: |
December 14, 2016 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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|
14229387 |
Mar 28, 2014 |
9540883 |
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15378992 |
|
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|
|
13477989 |
May 22, 2012 |
8783384 |
|
|
14229387 |
|
|
|
|
12276903 |
Nov 24, 2008 |
8191445 |
|
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13477989 |
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11948185 |
Nov 30, 2007 |
7695542 |
|
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12276903 |
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60917016 |
May 9, 2007 |
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|
60867882 |
Nov 30, 2006 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C22C 38/42 20130101;
C22C 38/04 20130101; B22F 2005/001 20130101; B32B 15/011 20130101;
C22C 38/34 20130101; B24D 3/342 20130101; B23D 61/185 20130101;
C22C 38/06 20130101; C22C 49/10 20130101; C22C 47/04 20130101; C22C
49/02 20130101; E21B 10/48 20130101; C22C 38/58 20130101; C22C
38/44 20130101; B22F 2007/066 20130101; C22C 49/14 20130101; B24D
3/06 20130101; C22C 49/08 20130101; C22C 38/00 20130101; C22C 38/50
20130101; C22C 38/56 20130101; C22C 38/46 20130101; C22C 26/00
20130101; C22C 38/02 20130101; C22C 38/002 20130101; C22C 38/60
20130101 |
International
Class: |
B24D 3/34 20060101
B24D003/34; C22C 38/60 20060101 C22C038/60; C22C 38/58 20060101
C22C038/58; C22C 38/56 20060101 C22C038/56; C22C 38/50 20060101
C22C038/50; C22C 38/46 20060101 C22C038/46; C22C 38/44 20060101
C22C038/44; C22C 38/42 20060101 C22C038/42; C22C 38/34 20060101
C22C038/34; C22C 38/06 20060101 C22C038/06; C22C 38/04 20060101
C22C038/04; C22C 38/02 20060101 C22C038/02; C22C 38/00 20060101
C22C038/00; C22C 49/14 20060101 C22C049/14; C22C 49/02 20060101
C22C049/02; B23D 61/18 20060101 B23D061/18; B24D 3/06 20060101
B24D003/06 |
Claims
1. A cutting tool comprising a cutting section, the cutting section
comprising: a matrix of hard particulate material; a binder
infiltrated therein the matrix of hard particulate material; a
plurality of cutting media dispersed within the matrix of hard
particulate material; and a plurality of metal fibers dispersed
within the matrix of hard particulate material.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of co-pending U.S. patent
application Ser. No. 14/229,387, filed Mar. 28, 2014, which is a
continuation-in-part of U.S. patent application Ser. No.
13/477,989, filed May 22, 2012, which is now U.S. Pat. No.
8,783,384, issued Jul. 22, 2014, which is a continuation of U.S.
patent application Ser. No. 12/276,903, filed Nov. 24, 2008, which
is now U.S. Pat. No. 8,191,445, issued Jun. 5, 2012, which is a
divisional of U.S. patent application Ser. No. 11/948,185, filed
Nov. 30, 2007, which is now U.S. Pat. No. 7,695,542, issued Apr.
13, 2010, which claims priority to and the benefit of U.S.
Provisional Application No. 60/917,016, filed May 9, 2007, and U.S.
Provisional Application No. 60/867,882, filed Nov. 30, 2006. The
contents of each of the above-referenced applications are hereby
incorporated by reference in their entirety.
BACKGROUND OF THE INVENTION
[0002] The Field of the Invention
[0003] This application relates generally to cutting tools and
their methods of use. In particular, this application relates to
diamond-impregnated cutting tools that may contain fibers.
[0004] Discussion of the Relevant Art
[0005] Cutting tools can be impregnated with diamonds so that they
can be used to grind, polish, or otherwise cut a variety of
materials that normal cutting tools cannot. The part of these tools
that performs the cutting action (or the cutting portion of the
tool) is generally formed of a matrix that contains a powdered
metal or a hard particulate material, such as tungsten carbide.
This material is sometimes infiltrated with a binder, such as a
copper alloy. Finally, the cutting portion of these tools is
impregnated with diamond crystals or some other form of abrasive
cutting media. As the tool grinds and cuts the desired materials,
the cutting portion of the tool erodes and exposes new layers of
the diamond crystal (or other cutting media) so that a sharp
surface is always available for the cutting process. Any
diamond-impregnated cutting tool may continue to cut efficiently
until the diamond impregnated portion of the tool is completely
consumed. At that point, the tool becomes dull and must be replaced
with another one.
[0006] In some cases, diamond-impregnated cutting tools may be
expensive and their replacement may be time consuming, costly, as
well as dangerous. For example, the replacement of a
diamond-impregnated core sampling drill bit requires removing (or
tripping out) the entire drill string out of the hole that has been
drilled (the borehole). Each section of the drill rod must be
sequentially removed from the borehole. Once the drill bit is
replaced, the entire drill string must be assembled section by
section and then tripped back into the borehole. Depending on the
depth of the hole and the characteristics of the materials being
drilled, this process may need to be repeated multiple times for a
single borehole.
[0007] As well, conventional diamond-impregnated cutting tools
often have several characteristics that can add to the consumption
rate of the cutting portion and, therefore, increase the operating
costs associated with those cutting tools. First, the binder
materials in the tools may be relatively soft in comparison to the
cutting media. Accordingly, the cutting portion may erode and allow
diamonds or other abrasive cutting materials to slough off
prematurely. Second, the erosion rate of the cutting portion can be
increased by insufficient lubrication to and around the cutting
face of the tool, or the interface between the cutting portion of
the tool and the material being cut. Third, conventional
impregnated cutting tools may also be too wear resistant to expose
and renew layers of the cutting portion.
SUMMARY
[0008] This application describes diamond-impregnated cutting tools
and their associated methods for manufacture and use. The cutting
tools contain a diamond-impregnated cutting portion that may
contain fibers made from carbon, glass, ceramic, polymer, and the
like. The fibers can be in any form, including chopped and milled
fibers. The fibers may also be coated with metal, ceramic, or other
performance-enhancing coatings. The fibers may be used to both
control the tensile strength control the erosion rate of the matrix
in the cutting portion to optimize the cutting performance of the
tools. Additionally, the fibers may also weaken the structure and
allow higher modulus binders to be used for the cutting tools at a
lower cost, allowing the amount of fibers to be tailored to retain
the diamonds in the cutting portion for the desired amount of time.
And as the cutting portion erodes, the fibers may also increase the
lubricity at the face of the cutting portion. Using the fibers
allows the cutting tools to last longer and make them safer and
more economical because they need to be replaced less often.
[0009] Additional advantages of the invention will be set forth in
part in the description which follows, and in part will be obvious
from the description, or may be learned by practice of the
invention. The advantages of the invention will be realized and
attained by means of the elements and combinations particularly
pointed out in the appended claims. It is to be understood that
both the foregoing general description and the following detailed
description are exemplary and explanatory only and are not
restrictive of the invention, as claimed.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] The following description can be better understood in light
of the Figures, in which:
[0011] FIG. 1 contains an exemplary view of a core sampling drill
bit;
[0012] FIG. 2 contains an exemplary view of a cross section of a
diamond wire;
[0013] FIG. 3 contains an exemplary view of a cross section of
another diamond wire; and
[0014] FIG. 4 contains an exemplary view of a cross section of an
individual diamond wire bead.
[0015] Together with the following description, the Figures may
help demonstrate and explain the principles of the invention and
methods for using the invention. In the Figures, the thickness and
configuration of components may be exaggerated for clarity. The
same reference numerals in different Figures represent the same
component.
DETAILED DESCRIPTION
[0016] The present invention may be understood more readily by
reference to the following detailed description, examples,
drawings, and claims, and their previous and following description.
However, before the present devices, systems, and/or methods are
disclosed and described, it is to be understood that this invention
is not limited to the specific devices, systems, and/or methods
disclosed unless otherwise specified, as such can, of course, vary.
It is also to be understood that the terminology used herein is for
the purpose of describing particular aspects only and is not
intended to be limiting.
[0017] The following description of the invention is provided as an
enabling teaching of the invention in its best, currently known
embodiment. To this end, those skilled in the relevant art will
recognize and appreciate that many changes can be made to the
various aspects of the invention described herein, while still
obtaining the beneficial results of the present invention. It will
also be apparent that some of the desired benefits of the present
invention can be obtained by selecting some of the features of the
present invention without utilizing other features. Accordingly,
those who work in the art will recognize that many modifications
and adaptations to the present invention are possible and can even
be desirable in certain circumstances and are a part of the present
invention. Thus, the following description is provided as
illustrative of the principles of the present invention and not in
limitation thereof.
[0018] As used throughout, the singular forms "a," "an" and "the"
include plural referents unless the context clearly dictates
otherwise. Thus, for example, reference to "a fiber" can include
two or more such fibers unless the context indicates otherwise.
[0019] Ranges can be expressed herein as from "about" one
particular value, and/or to "about" another particular value. When
such a range is expressed, another aspect includes from the one
particular value and/or to the other particular value. Similarly,
when values are expressed as approximations, by use of the
antecedent "about," it will be understood that the particular value
forms another aspect. It will be further understood that the
endpoints of each of the ranges are significant both in relation to
the other endpoint, and independently of the other endpoint.
[0020] As used herein, the terms "optional" or "optionally" mean
that the subsequently described event or circumstance may or may
not occur, and that the description includes instances where said
event or circumstance occurs and instances where it does not.
[0021] The cutting tools described herein can be used to cut stone,
subterranean mineral formations, ceramics, asphalt, concrete, and
other hard materials. These cutting tools may include core sampling
drill bits, drag-type drill bits, roller cone drill bits, diamond
wire, grinding cups, diamond blades, tuck pointers, crack chasers,
and the like. For example, the cutting tools may be any type of
earth drill bit (i.e., core sampling drill bit, drag drill bit,
roller cone bit, navi-drill, full hole drill, hole saw, hole
opener, etc.), diamond saw blade (e.g., laser welded blade, concave
diamond blade, segmented blade, continuous rim blade, wavy core
blade, ventilated core blade, etc.), grinding cup (e.g., single row
cup, double row cup, grinding cup with T-shaped segments, etc.),
tuck pointer (e.g., triple row, etc.), crack chaser, polishing
disk, and so forth. In some embodiments, though, the cutting tools
are core sampling drill bits and diamond wire.
[0022] The part of the cutting tools that performs the cutting
action (or the cutting portion of the tool) contains a matrix with
a powdered metal or a hard particulate material, such as tungsten
carbide or any other super-abrasive material. This material can
sometimes be infiltrated with a binder, such as a copper alloy or a
substantial equivalent, and can be sintered to form a segment. The
cutting portion of these tools can also be impregnated with
diamonds, or some other form of abrasive cutting media, and mixed
(and, in some embodiments, reinforced) with fibrous materials (or
fibers) as described in detail in the embodiments where the cutting
tool is a core sampling drill bit and a diamond wire.
[0023] FIG. 1 illustrates one example of a fiber-containing cutting
tool, a fiber-containing (and, in some embodiments,
fiber-reinforced) core sampling drill bit. As shown in FIG. 1, the
drill bit 20 contains a first section 21 that connects to the rest
of the drill string. The drill bit 20 also contains a second
section 22 that is used to cut the desired materials during the
drilling process. The body of the drill bit 20 has an outer surface
and an inner surface containing a hollow portion therein. With this
configuration, pieces of the material being drilled can pass
through the hollow portion, up into a drill string to which the
drill bit is connected, and then be collected.
[0024] The drill bit 20 may be any size, and may therefore be used
to collect core samples of any size. While the drill bit may have
any circumference and may be used to remove and collect core
samples with any desired diameter, the diameter generally ranges
from about 1 to about 12 inches. As well, while the kerf of the
drill bit (the radius of the outer surface minus the radius of the
inner surface) may be any width, it generally ranges from about 1/2
of an inch to about 6 inches.
[0025] The first section 21 of the drill bit may be made of any
suitable material known in the art. In some embodiments, the first
section may be made of steel or a matrix casting of a hard
particulate material in a binder. In some embodiments, the first
section 21 may contain a chuck end, sometimes called a blank, bit
body, or shank, that may be used for any purpose, including
connecting the drill bit to the nearest part of the drill string.
Thus, the chuck end can be configured as known in the art to
connect the drill bit 20 to any desired part of the drill
string.
[0026] The second section 22 of the core sampling drill bit 20
contains a cutting portion with cutting elements 12 having a
cutting face 14. The cutting elements 12 have a space 16 between
them so that, as known in the art, a drilling fluid following the
path shown by the arrow may be used during drilling. The cutting
portion of the core sampling drill bit, often called the crown, may
be constructed of any material(s) known in the art. This type of
drill bit (a core sampling bit) is generally formed of steel or a
matrix of powdered metal, which is a hard particulate material,
such as tungsten carbide, tungsten, iron, cobalt, and/or
molybdenum. This material may then be infiltrated with a binder,
such as a copper alloy, zinc, silver, molybdenum, nickel, cobalt,
or a substantial equivalent, and/or may be sintered. The cutting
portion of the drill bit may also be impregnated with any form or
combination of forms of cutting media, such as diamond
crystals.
[0027] The cutting media used in the drill bit may have any desired
characteristic or grain, quality, grit, concentration, etc. In some
embodiments, the cutting media may be very small and substantially
round in order to leave a smooth finish on the material being cut
by the core sampling drill bit. In other embodiments, the cutting
media may be larger to cut aggressively into the material being
cut.
[0028] The cutting media may be contained homogeneously or
heterogeneously in the drill bit. As well, the cutting media may be
aligned in a particular manner so that the cutting properties of
the media are presented in an advantageous position with respect to
the cutting portion of the drill bit. Similarly, the cutting media
may be contained in the drill bit in a variety of densities as
desired for a particular use. For example, large abrasive particles
spaced further apart may cut material more quickly than small
abrasive particles packed tightly together. But the size, density,
and shape of the abrasive particles may be provided in a variety of
combinations depending on desired cost and performance of the drill
bit.
[0029] In some instances, the cutting portion of the drill bit may
be made of one or more layers. For example, the cutting portion may
contain two layers: a matrix layer that performs the cutting
operation and a backing layer, which connects the matrix layer to
the first section of the drill bit. In these embodiments, the
matrix layer contains the actual cutting media that abrades and
erodes the material being drilled. The portion of the matrix layer
that comes in contact with the material being cut is known as the
cutting face.
[0030] Another embodiment of a cutting tool comprises a
fiber-containing (and, in some embodiments, a fiber-reinforced)
diamond wire segments or beads. Diamond wire may be used to cut a
variety of hard materials. For example, a relatively large diamond
wire may be used to cut large blocks of granite out of a granite
formation in a quarry for further processing. However, in other
uses, a relatively small diamond wire may be used in a laboratory
to cut a sample of a hard material for testing.
[0031] One example a diamond wire is shown in FIG. 2. In FIG. 2,
the diamond wires contain a core wire 2 made of any suitable strong
material, such as steel, that may be coated with a cutting material
coating 4. The coating 4 in such wires may act as the cutting
portion of the diamond wire. The coating 4 may contain a binder
(e.g., a copper alloy, iron, silicon carbide, etc.) and a base
material that may be formed from steel or a matrix of powdered
metal/hard particulate material (e.g., tungsten carbide, tungsten,
iron, cobalt, molybdenum, etc.). The coating 4 may also be
impregnated with any cutting media 8, such as diamond crystals. The
cutting media 8 in the coating 4 may have any desired
characteristic, including any size, shape, alignment, grain,
quality, grit, concentration, disbursement, and so forth.
[0032] In some instances, the coating 4 of the diamond wire may be
made of one or more layers. In such embodiments, each layer may be
made of any desired material. For example, the backing layer may
contain an iron alloy and the bond between the matrix and backing
layer is usually achieved with a copper alloy or braze alloy.
[0033] FIG. 3 illustrates another example of a fiber-containing
diamond wire. As shown in FIG. 3, the diamond wires may have
abrasive beads that are applied to a core portions on the diamond
wire. The abrasive beads may be formed from any suitable material.
For example, the abrasive beads may have a diamond matrix 27 formed
of a base material, like powdered metal or a hard particulate
material (e.g., tungsten carbide, tungsten, cobalt, molybdenum,
etc.). The base material may be infiltrated with a binding material
(e.g., a copper alloy). And the abrasive beads may be impregnated
with any cutting media (e.g., diamond crystals) having any desired
characteristic, including any size, shape, alignment, grain,
quality, grit, concentration, disbursement, and the like.
[0034] FIG. 4 illustrates an individual diamond wire bead 26 that
is used with the diamond wire shown in FIG. 3. The bead 26 may be
of any shape and size known in the art and may be applied to the
core wire in any manner known in the art. The diamond wire in FIG.
3, for example, may be made by manufacturing the bead 26 to contain
a coating 34 with abrasive particles 38 and fibers 36 and a channel
32. In this example, the bead 26 may then be attached to a steel
ferrule, which may be threaded onto the core wire. Therefore, the
beads 26 on the diamond wire may be manufactured separately from
the core wire and then strung on the core wire with other beads to
create the diamond wire. An encapsulant, usually a rubber 25 or
some other polymeric material, can be coated on the core wire
between the beads as known in the art to create the diamond
wire.
[0035] The diamond wires may also be any size and may therefore be
used in any known process using diamond wire. For example, the
diamond wire in FIG. 3 may range in length from about 5 meters to
more than 100 meters and have beads 26 with a diameter of from
about 4 millimeters to about 12 millimeters. And for the diamond
wire in FIG. 2, the length can be about 10 centimeters long and the
diameter of the core wire and cutting material coating can be about
a few microns. Nevertheless, the diamond wire can be longer or
shorter than the lengths in the previous examples and may also have
beads and a cable of any desired diameter.
[0036] In addition to these features, the diamond-impregnated
cutting tools-including the core sampling drill bits or diamond
wires-may have any additional feature known in the art. For
example, a core sampling drill bit may have additional gauge
protection, hard-strip deposits, various bit profiles, and
combinations thereof. Protector gauges on or in a drill bit may be
included to reduce the damage to the drill bit and well casing as
the drill bit cuts the formation. Additionally, the core sampling
drill bit may have hard-metal strips applied that may prevent the
premature erosion of the support portion of the drill bit.
[0037] The cutting portion(s) of the diamond-impregnated cutting
tools contain fibers. Any known fiber, or combination of fibers,
may be added to the cutting tool. In some embodiments, the cutting
portion of a diamond-impregnated cutting tool may include fibers
such as carbon fibers, metal fibers (e.g., fibers made of tungsten,
tungsten carbide, iron, molybdenum, cobalt, or combinations
thereof), glass fibers, polymeric fibers (e.g., fibers made of
Kevlar), ceramic fibers (e.g., fibers made of silicon carbide),
coated fibers, and/or the like.
[0038] For example, and with limitation, it is contemplated that
exemplary metal fibers can comprise steel alloys such as, without
limitation, carbon steel (low/mild/high alloy), ferroalloys, cast
iron alloys, pig iron alloys, chromoly steel alloys, high-speed
steel alloys, stainless steel alloys, tool steel alloys, and the
like.
[0039] In one exemplary aspect, the exemplary steel fiber can have
a 0.1 mm diameter.times.1.7 mm length and can comprise medium
carbon low-alloy steel. Optionally, the exemplary steel fiber can
be sized between about 0.004 mm to about 15 mm in diameter and
between about 0.05 mm to about 75 mm in length. In a further
aspect, the exemplary steel fiber can be sized between about 0.008
mm to about 10 mm in diameter and between about 0.1 mm to about 50
mm in length.
[0040] In a further aspect, it is contemplated that the typical
composition of the steel metal fiber can comprise at least one or
more of: Aluminum (between about 0.95% to about 1.3%); Bismuth
(0.01% to about 0.15%); Carbon (between about 0.05% to about 2.1%);
Chromium (between about 0.5% to about 18.0%); Copper (between about
0.1% to about 0.4%); Lead (0.01% to about 0.15%); Manganese
(between about 0.25% to about 18.0%); Molybdenum (between about
0.2% to about 5.0%); Nickel (between about 2.0% to about 20.0%);
Silicon (between about 0.2% to about 2.0%); Sulfur (between about
0.08% to about 0.15%); Titanium (0.01% to about 0.15%); Tungsten
(0.01% to about 3.0%); Vanadium (0.01% to about 0.15%) and
Iron.
[0041] Optionally, it is contemplated that the metal fibers can
comprise one or more of alloys selected from titanium and titanium
alloys, cobalt and cobalt alloys, nickel and nickel alloys,
manganese and manganese alloys, chromium and chromium alloys, and
the like. In a further aspect, the coating materials described
herein can comprise can comprise one or more of alloys selected
from titanium and titanium alloys, cobalt and cobalt alloys, copper
and copper alloys, nickel and nickel alloys, manganese and
manganese alloys, chromium and chromium alloys, tin and tin alloys,
tungsten and tunsgten alloys, and zinc and zinc alloys.
[0042] In some embodiments, the cutting portion of a
diamond-impregnated cutting tool may contain any carbon fibers. Any
known type of carbon fiber may be included in the cutting portion
of a diamond-impregnated cutting tool.
[0043] In some embodiments, the fibers may optionally be coated
with one or more additional material(s) before being included in
the cutting tool. Such coatings may be used for any
performance-enhancing purpose. For example, a fiber coating may be
used to help retain fibers in the cutting tool. In another example,
a fiber coating may be used to increase lubricity near the cutting
face of a cutting tool as the fiber coating erodes away and forms a
fine particulate material that acts to reduce friction. In yet
another example, a fiber coating may act as an abrasive material
and thereby be used to aid in the cutting process.
[0044] Any known material may be used to coat the type of fiber(s)
that is used in the cutting tool. For example, any desired metal,
ceramic, polymer, glass, sizing, wetting agent, flux, or other
substance could be used to coat a desired type of fiber(s) that may
be included in a cutting tool. In one example, carbon fibers could
be coated with a metal, such as iron, titanium, nickel, copper,
molybdenum, lead, tungsten, aluminum, chromium, tungsten, copper,
tin, zinc or combinations thereof. In another example, carbon
fibers may be coated with a ceramic material, such as SiC, SiO,
Si02, or the like.
[0045] Where fibers are coated with one or more coatings, the
coating material may cover any portion of the fibers and may be of
any desired thickness. Accordingly, a coating material may be
applied to the fibers in any manner known in the art. For example,
the coating may be applied to fibers through spraying, brushing,
electroplating, immersion, vapor deposition, or chemical vapor
deposition.
[0046] The fibers in the cutting portion of a diamond-impregnated
cutting tool, such as a core sampling drill bit, may be of any size
or combination of sizes, including mixtures of different sizes. For
instance, fibers may be of any length and have any desired
diameter. In some embodiments, the fibers may be approximately 10
to about 25,000 microns long and may have a diameter of
approximately 1 to about 500 microns. In other embodiments, the
fibers may be approximately 150 microns in length and may have a
diameter of approximately 7 microns.
[0047] The fibers may be of any shape or combination of shapes. The
fibers may be ribbon-like, cylindrical, polygonal, elliptical,
straight, curved, curly, coiled, bent at angles, etc. For instance,
FIG. 2 illustrates that in some embodiments, the majority of the
fibers 6 may be curved. In other embodiments, such as when the
cutting tool comprises a core sampling drill bit, the fibers have a
substantially cylindrical shape.
[0048] Additionally, the fibers may also be of any type or
combination of types. Examples of the types of fibers include
chopped, milled, braided, woven, grouped and wound, or tows. In
some embodiments, such as when the cutting tool comprises a core
sampling drill bit, the fibers can contain a mixture of chopped and
milled fibers. In some embodiments, a diamond-impregnated cutting
tool contains one type of fiber. In other embodiments, though, the
cutting tool may contain multiple types of fibers. In such
instances, where a cutting tool contains more than one type of
fiber, any combination of fiber type, quality, size, shape, grade,
coating, and/or fiber with any other characteristic may be
used.
[0049] The fibers may be found in any desired concentration in the
cutting tool. For instance, the cutting portion of a cutting tool
may have a very high concentration of fibers, a very low
concentration of fibers, or any concentration in between. In some
embodiments, the cutting tool may contain fibers ranging from about
0.1 to about 70 vol %. In other embodiments, the cutting tool may
contain fibers ranging from about 0.1 to about 30 vol %. A first
portion of the cutting tool may have a first concentration of a
particular type of reinforcing fiber and another portion may have a
different concentration (either lower or higher) of the same or
another type of reinforcing fiber.
[0050] In some embodiments, fibers may be homogenously dispersed
throughout the cutting portion of a cutting tool. In other
embodiments, though, the concentration of fibers may vary
throughout any desired portion of a cutting tool, as desired.
Indeed, any desired variation of the concentration of fibers may be
implemented in a cutting tool. For example, where the cutting tool
comprises a core sampling drill bit, it may contain a gradient of
fibers. In this example, the portion of the matrix layer that is
closest to the cutting face of the drill bit may contain a first
concentration of fibers and the concentration of fibers could
gradually decrease or increase towards the backing layer. Such a
drill bit may be used to drill a formation that begins with a soft,
abrasive, unconsolidated formation, which gradually shifts to a
hard, non-consolidated formation. Thus, the dispersal of the fibers
in the drill bit can be customized to the desired earth formation
through which it will be drilling.
[0051] The fiber concentration may also vary in any desired manner
in the cutting tool. In other words, a cutting tool may comprise
sections, strips, spots, rings, or any other formation that
contains a different concentration or mixture of fiber
reinforcements than other parts of the cutting tool. For example,
the cutting portion of a drill bit may comprise multiple layers,
rings, or segments of matrix layer containing fibers. Each ring,
layer, or segment of the drill bit may have a roughly homogenous
(or heterogeneous) concentration of fibers throughout the entire
ring, layer or segment. Yet the concentration of fibers may vary
from ring to ring (or from segment to segment, etc . . . ). And the
various rings of differing fiber gradients may be arranged in any
order, may contain different fibers or combinations of fibers, and
may be of any desired thickness. In another example, the outer and
inner surfaces of a drill bit could be provided with a different
concentration of fibers than the inner parts of the drill bit.
[0052] The fibers may be located in the cutting portion of a
cutting tool in any desired orientation or alignment. In some
embodiments, the fibers may run roughly parallel to each other in
any desired direction. However, FIGS. 2 and 4 illustrate that, in
other embodiments, the fibers may be randomly configured and may
thereby be oriented in practically any and/or every direction.
[0053] The diamond-impregnated cutting tools with fibers can be
made using any known method that provides them with the features
described above. For example, the drill bit described above can be
made in the following exemplary manner. In this example, the first
section of the drill bit can be made with any known method. The
fibers can be incorporated into the drill bit using any method that
provides the desired fibers in the desired location with the
desired concentration. For instance, the fibers may be mixed in
with the powdered metal that is used to make the crown of the drill
bit. This mixture may then be sintered and/or infiltrated with a
binder. In other embodiments, though, the fibers may be
incorporated by just placing them into the mold that is used to
make the crown of the drill bit. The first section of the drill bit
can then be connected to the second section using any method known
in the art. For example, the first section may be present in the
mold that is used to form the second section of the drill bit and
the two ends of the body may be fused together. Alternatively, the
first and second sections can be mated in a secondary process such
as by brazing, welding, or adhesive bonding.
[0054] The diamond-impregnated cutting tools with fibers may be
used for any purpose known in the art, which depends on the type of
cutting tool. For example, a diamond-impregnated core sampling
drill bit may be attached to the end of a drill string, which is in
turn connected to a drilling rig. As the drill string and therefore
the drill bit is rotated and pushed by the drill bit, it grinds
away the materials in the subterranean formations that are being
drilled. The core samples that are drilled away are withdrawn from
the drill string. The cutting portion of the drill bit will erode
over time because of the grinding action. This process may continue
until the cutting portion of a drill bit has been consumed and the
drilling string need be tripped out of the borehole and the drill
bit replaced.
[0055] The described fibers give diamond-impregnated cutting tools
several added advantages when compared to conventional cutting
tools that lack fibers. First, the addition of the fibers can
control the tensile strength and the erosion rate of the cutting
tool, whether to strengthen or weaken these properties. Without
being restricted to this understanding, it is believed that the
presence of the fibers can be used to modify the amount of voids in
the cutting portion of the tools. And since the tensile strength
and erosion rate depend on the amount of voids, modifying the
amount of the fibers can be used to tailor the tensile strength and
the erosion rate to the amount needed for the particular end use of
the cutting tool. This increased tensile strength can also increase
the life of a cutting tool, allowing the cutting portion of the
tools to wear at a desired pace and improving the rate at which the
tool cuts.
[0056] Second, the addition of fibers may also weaken the structure
of the cutting portion and allow higher modulus binders to be used
for the cutting tools, but at a lower cost. Thus, the amount of
fibers in the cutting portion can be tailored to retain the
diamonds in the cutting portion for the desired length of time.
[0057] A third advantage is that the fibers may also act as
abrasive cutting media that aid in the cutting process. A fourth
advantage is that as the fibers in the cutting portion erode away,
their fine particulate matter can reduce friction and increase the
lubrication at the interface between the cutting portion and the
surface being cut, allowing easier cutting and better flushing.
This increased lubrication may also reduce the amount of cutting
lubricants (such as drilling muds, polymers, bentonites, etc. . .)
that are needed, reducing the costs as well as the environmental
impact that can be associated with using diamond-impregnated
cutting tools.
EXAMPLE
[0058] In one example of a comparison between a conventional
diamond-impregnated cutting tool (one lacking fibers) and a
fiber-containing diamond-impregnated cutting tool, two sets of
substantially similar drill bits were manufactured. In this
comparison, the first set of drill bits contained no fibers and the
second set was reinforced with carbon fibers. Each drill bit was
then tested and the following properties were measured.
[0059] Penetration Rate: The average penetration rates of the first
set of drill bits ranged from about 30 to about 40 meters per
shift. Nevertheless, with the second set of fiber-reinforced bits,
the drillers consistently achieved about 50 meters per shift. This
equates to an increase in penetration rate of about 25% to about
67%.
[0060] Bit life: The average bit life of the first set of drill
bits was 64 meters. Conversely, the average bit life of the second
set of drill bits was about 104 meters. This equates to an increase
in bit life of about 60%.
[0061] In addition to any previously indicated modification,
numerous other variations and alternative arrangements may be
devised by those skilled in the art without departing from the
spirit and scope of the above description, and appended claims are
intended above with particularity and detail in connection with
what is presently deemed to be the most practical and exemplary
embodiments, it will be apparent to those of ordinary in the art
that numerous modifications, including, but not limited to, form,
functions, manner of operation and use may be made without
departing from the principles and concepts set forth herein. Also,
as used herein, examples and embodiments are meant to be
illustrative only and should not be construed as limiting in any
manner.
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