U.S. patent application number 14/633041 was filed with the patent office on 2016-09-15 for methods of making a polycrystalline diamond compact including a polycrystalline diamond table with a thermally-stable region having at least one low-carbon-solubility material.
The applicant listed for this patent is US SYNTHETIC CORPORATION. Invention is credited to Kenneth E. Bertagnolli, Paul Douglas Jones, C. Eugene McMurray, David P. Miess, Michael A. Vail.
Application Number | 20160263725 14/633041 |
Document ID | / |
Family ID | 50982020 |
Filed Date | 2016-09-15 |
United States Patent
Application |
20160263725 |
Kind Code |
A1 |
Miess; David P. ; et
al. |
September 15, 2016 |
METHODS OF MAKING A POLYCRYSTALLINE DIAMOND COMPACT INCLUDING A
POLYCRYSTALLINE DIAMOND TABLE WITH A THERMALLY-STABLE REGION HAVING
AT LEAST ONE LOW-CARBON-SOLUBILITY MATERIAL
Abstract
Embodiments of the invention relate to polycrystalline diamond
compacts ("PDCs") comprising a polycrystalline diamond ("PCD")
table including a thermally-stable region having at least one
low-carbon-solubility material disposed interstitially between
bonded diamond grains thereof, and methods of fabricating such
PDCs. In an embodiment, a PDC includes a substrate, and a PCD table
bonded to the substrate. The PCD table includes a plurality of
diamond grains exhibiting diamond-to-diamond bonding therebetween
and defining a plurality of interstitial regions. The PCD table
further includes at least one low-carbon-solubility material
disposed in at least a portion of the plurality of interstitial
regions. The at least one low-carbon-solubility material exhibits a
melting temperature of about 1300.degree. C. or less and a bulk
modulus at 20.degree. C. of less than about 150 GPa.
Inventors: |
Miess; David P.; (Highland,
UT) ; Vail; Michael A.; (Genola, UT) ;
Bertagnolli; Kenneth E.; (Riverton, UT) ; McMurray;
C. Eugene; (Galion, OH) ; Jones; Paul Douglas;
(Elk Ridge, UT) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
US SYNTHETIC CORPORATION |
OREM |
UT |
US |
|
|
Family ID: |
50982020 |
Appl. No.: |
14/633041 |
Filed: |
February 26, 2015 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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14570506 |
Dec 15, 2014 |
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14633041 |
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13027954 |
Feb 15, 2011 |
9017438 |
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14570506 |
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11545929 |
Oct 10, 2006 |
8236074 |
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13027954 |
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12394356 |
Feb 27, 2009 |
8080071 |
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11545929 |
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61068120 |
Mar 3, 2008 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B24D 3/02 20130101; B24D
3/10 20130101; B24D 3/06 20130101; B24D 18/0009 20130101; E21B
10/567 20130101; B24D 99/005 20130101; E21B 10/5676 20130101 |
International
Class: |
B24D 3/06 20060101
B24D003/06; B24D 18/00 20060101 B24D018/00; E21B 10/567 20060101
E21B010/567 |
Claims
1. A polycrystalline diamond compact, comprising: a substrate; and
a polycrystalline diamond table bonded to the substrate, the
polycrystalline diamond table including a plurality of diamond
grains exhibiting diamond-to-diamond bonding therebetween and
defining a plurality of interstitial regions, at least a portion of
the plurality of interstitial regions including one or more first
interstitial materials disposed therein, the one or more first
interstitial materials including one or more of a eutectic material
or a near eutectic material exhibiting a melting temperature of
about 180.degree. C. to about 1300.degree. C.
2. The polycrystalline diamond compact of claim 1 wherein the one
or more of the eutectic material or the near eutectic material
include one or more alloys including at least one of copper, tin,
indium, gadolinium, germanium, gold, silver, aluminum, lead, zinc,
cadmium, bismuth, or antimony.
3. The polycrystalline diamond compact of claim 2 wherein the one
or more of the eutectic material or the near eutectic material
exhibit a bulk modulus at 20.degree. C. of less than about 150
GPa.
4. The polycrystalline diamond compact of claim 2 wherein the one
or more of the eutectic material or the near eutectic material
exhibit a thermal expansion of about 3.times.10.sup.-6 per .degree.
C. to about 20.times.10.sup.-6 per .degree. C.
5. The polycrystalline diamond compact of claim 1 wherein the
polycrystalline diamond table includes a first region and a second
region, the first region including the one or more first
interstitial materials therein and being more thermally stable than
the second region.
6. The polycrystalline diamond compact of claim 5 wherein the
second region is bonded to the substrate.
7. The polycrystalline diamond compact of claim 5 wherein the first
region extends inward from a working surface of the polycrystalline
diamond table.
8. The polycrystalline diamond compact of claim 5 wherein the one
or more of the eutectic material or the near eutectic material is
about 1 weight percent to about 10 weight percent of the first
region of the polycrystalline diamond table.
9. The polycrystalline diamond compact of claim 5 wherein the
second region includes a second interstitial material that is
different from the one or more first interstitial materials.
10. The polycrystalline diamond compact of claim of claim 9 wherein
the second interstitial material includes at least one of iron,
nickel, or cobalt.
11. The polycrystalline diamond compact of claim of claim 10
wherein the second interstitial material is present in the second
region of the polycrystalline diamond table in an amount of about
2.0 weight percent or less.
12. The polycrystalline diamond compact of claim of claim 1 wherein
the one or more first interstitial materials includes a
metal-solvent catalyst.
13. The polycrystalline diamond compact of claim of claim 12
wherein the metal-solvent catalyst includes at least one of iron,
nickel, or cobalt.
14. A polycrystalline diamond compact, comprising: a substrate; and
a polycrystalline diamond table bonded to the substrate, the
polycrystalline diamond table including a plurality of diamond
grains exhibiting diamond-to-diamond bonding therebetween and
defining a plurality of interstitial regions, the polycrystalline
diamond including a working surface spaced from an interfacial
surface, the polycrystalline diamond table including: a first
region extending inwardly from the interfacial surface, the first
region including a first interstitial material located in at least
a portion of the plurality of interstitial regions thereof, the
first interstitial material including a metal-solvent catalyst; and
a second region extending inwardly from the working surface and
exhibiting a generally ring-like geometry encircling a portion of
the first region and being spaced from the interfacial surface by a
portion of the second region, the second region including one or
more second interstitial materials having one or more of a eutectic
material or a near eutectic material exhibiting a melting
temperature of about 1300.degree. C. or less.
15. The polycrystalline diamond compact of claim 14 wherein the one
or more of the eutectic material or the near eutectic material
includes one or more alloys including at least one of copper, tin,
indium, gadolinium, germanium, gold, silver, aluminum, lead, zinc,
cadmium, bismuth, or antimony.
16. The polycrystalline diamond compact of claim 14 wherein the one
or more of the eutectic material or the near eutectic material
exhibit a bulk modulus at 20.degree. C. of less than about 150
GPa.
17. The polycrystalline diamond compact of claim 14 wherein the one
or more of the eutectic material or the near eutectic material
exhibit a thermal expansion of about 3.times.10.sup.-6 per .degree.
C. to about 20.times.10.sup.-6 per .degree. C.
18. The polycrystalline diamond compact of claim 14 wherein the
second region is more thermally stable than the first region.
19. The polycrystalline diamond compact of claim 14 wherein the
first region is bonded to the substrate.
20. The polycrystalline diamond compact of claim 14 wherein the one
or more of the eutectic material or the near eutectic material is
about 1 weight percent to about 10 weight percent of the first
region of the polycrystalline diamond table.
21. The polycrystalline diamond compact of claim of claim 14
wherein the first interstitial material includes at least one of
iron, nickel, or cobalt.
22. A polycrystalline diamond compact, comprising: a substrate; and
a polycrystalline diamond table bonded to the substrate, the
polycrystalline diamond table including a plurality of diamond
grains exhibiting diamond-to-diamond bonding therebetween and
defining a plurality of interstitial regions, at least a portion of
the plurality of interstitial regions including one or more first
interstitial materials disposed therein, the one or more first
interstitial materials including one or more of a eutectic material
or a near eutectic material exhibiting a melting temperature of
about 180.degree. C. to about 1300.degree. C. and a coefficient of
thermal expansion of about 3.times.10.sup.-6 per .degree. C. to
about 20.times.10.sup.-6 per .degree. C.
23. The polycrystalline diamond compact of claim 22 wherein the one
or more of the eutectic material or the near eutectic material
exhibit a bulk modulus at 20.degree. C. of about 30 GPa to 150
GPa.
24. The polycrystalline diamond compact of claim 22 wherein the one
or more of the eutectic material or the near eutectic material
exhibit a bulk modulus at 20.degree. C. of less than about 130
GPa.
25. The polycrystalline diamond compact of claim 22 wherein the one
or more of the eutectic material or the near eutectic material
includes one or more alloys including at least one of copper, tin,
indium, gadolinium, germanium, gold, silver, aluminum, lead, zinc,
cadmium, bismuth, or antimony.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. patent
application Ser. No. 14/570,506 filed on 15 Dec. 2014, which is a
divisional application of U.S. patent application Ser. No.
13/027,954 filed on 15 Feb. 2011, which is a continuation-in-part
of U.S. patent application Ser. No. 11/545,929 filed on 10 Oct.
2006 (now U.S. Pat. No. 8,236,074 issued on 7 Aug. 2012) and U.S.
patent application Ser. No. 12/394,356 filed on 27 Feb. 2009 (now
U.S. Pat. No. 8,080,071 issued on 20 Dec. 2011) which claims the
benefit of U.S. Provisional Application No. 61/068,120 filed on 3
Mar. 2008. The contents of each of the foregoing applications are
incorporated herein, in their entirety, by this reference.
BACKGROUND
[0002] Wear-resistant, polycrystalline diamond compacts ("PDCs")
are utilized in a variety of mechanical applications. For example,
PDCs are used in drilling tools (e.g., cutting elements, gage
trimmers, etc.), machining equipment, bearing apparatuses,
wire-drawing machinery, and in other mechanical apparatuses.
[0003] PDCs have found particular utility as superabrasive cutting
elements in rotary drill bits, such as roller-cone drill bits and
fixed-cutter drill bits. A PDC cutting element typically includes a
superabrasive diamond layer commonly known as a diamond table. The
diamond table is formed and bonded to a substrate using a
high-pressure/high-temperature ("HPHT") process. The PDC cutting
element may also be brazed directly into a preformed pocket,
socket, or other receptacle formed in a bit body. The substrate may
often be brazed or otherwise joined to an attachment member, such
as a cylindrical backing A rotary drill bit typically includes a
number of PDC cutting elements affixed to the bit body. It is also
known that a stud carrying the PDC may be used as a PDC cutting
element when mounted to a bit body of a rotary drill bit by
press-fitting, brazing, or otherwise securing the stud into a
receptacle formed in the bit body.
[0004] Conventional PDCs are normally fabricated by placing a
cemented carbide substrate into a container with a volume of
diamond particles positioned on a surface of the cemented carbide
substrate. A number of such containers may be loaded into an HPHT
press. The substrate(s) and volume of diamond particles are then
processed under HPHT conditions in the presence of a catalyst
material that causes the diamond particles to bond to one another
to form a matrix of bonded diamond grains defining a
polycrystalline diamond ("PCD") table. The catalyst material is
often a metallic catalyst (e.g., cobalt, nickel, iron, or alloys
thereof) that is used for promoting intergrowth of the diamond
particles.
[0005] In one conventional approach, a constituent of the cemented
carbide substrate, such as cobalt from a cobalt-cemented tungsten
carbide substrate, liquefies and sweeps from a region adjacent to
the volume of diamond particles into interstitial regions between
the diamond particles during the HPHT process. The cobalt acts as a
metal-solvent catalyst to promote intergrowth between the diamond
particles, which results in the formation of a matrix of bonded
diamond grains having diamond-to-diamond bonding therebetween, with
interstitial regions between the bonded diamond grains being
occupied by the metal-solvent catalyst.
[0006] The presence of the metal-solvent catalyst in the PCD table
is believed to reduce the thermal stability of the PCD table at
elevated temperatures. For example, some of the diamond grains can
undergo a chemical breakdown or back-conversion to a non-diamond
form of carbon via interaction with the metal-solvent catalyst. At
elevated high temperatures, portions of diamond grains may
transform to carbon monoxide, carbon dioxide, graphite, or
combinations thereof, causing degradation of the mechanical
properties of the PCD table.
[0007] Despite the availability of a number of different PDCs,
manufacturers and users of PDCs continue to seek PDCs that exhibit
improved toughness, wear resistance, thermal stability, or
combinations of the foregoing.
SUMMARY
[0008] Embodiments of the invention relate to PDCs comprising a PCD
table including a thermally-stable region having at least one
low-carbon-solubility material disposed interstitially between
bonded diamond grains thereof, and methods of fabricating such
PDCs. The at least one low-carbon-solubility material may exhibit a
melting temperature of about 1300.degree. C. or less and a bulk
modulus at 20.degree. C. of less than about 150 GPa. The at least
one low-carbon-solubility material, in combination with the high
diamond-to-diamond bond density of the diamond grains, may enable
the at least one low-carbon-solubility material to be extruded
between the diamond grains and out of the PCD table before causing
the PCD table to fail during cutting operations as a result of
interstitial-stress-related fracture.
[0009] In an embodiment, a PDC includes a substrate, and a PCD
table bonded to the substrate. The PCD table includes a plurality
of diamond grains exhibiting diamond-to-diamond bonding
therebetween and defining a plurality of interstitial regions. The
PCD table further includes at least one low-carbon-solubility
material disposed in at least a portion of the plurality of
interstitial regions. The at least one low-carbon-solubility
material exhibits a melting temperature of about 1300.degree. C. or
less and a bulk modulus at 20.degree. C. of less than about 150
GPa.
[0010] In an embodiment, a method of manufacturing a PDC includes
forming an assembly including an at least partially leached
polycrystalline diamond table including a plurality of interstitial
regions therein positioned at least proximate to a substrate and at
least proximate to at least one layer including at least one
low-carbon-solubility material. The at least one
low-carbon-solubility material exhibits a melting temperature of
about 1300.degree. C. or less and a bulk modulus at 20.degree. C.
of less than about 150 GPa. The method further includes
infiltrating the at least one low-carbon-solubility material into
at least a portion of the interstitial regions of a selected region
of the at least partially leached polycrystalline diamond
table.
[0011] In an embodiment, a method of manufacturing a PDC in a
single-step HPHT process is disclosed. The method includes forming
an assembly including a plurality of diamond particles disposed at
least proximate to a substrate and at least proximate to at least
one low-carbon-solubility material having carbon ions implanted
therein. The at least one low-carbon-solubility material exhibits a
melting temperature of about 1300.degree. C. or less and a bulk
modulus at 20.degree. C. of less than about 150 GPa. The method
further includes subjecting the assembly to a
high-pressure/high-temperature process to sinter the diamond
particles in the presence of the at least one low-carbon-solubility
material having the carbon ions implanted therein to form a
polycrystalline diamond table that bonds to the substrate.
[0012] Other embodiments include applications utilizing the
disclosed PDCs in various articles and apparatuses, such as rotary
drill bits, bearing apparatuses, wire-drawing dies, machining
equipment, and other articles and apparatuses.
[0013] Features from any of the disclosed embodiments may be used
in combination with one another, without limitation. In addition,
other features and advantages of the present disclosure will become
apparent to those of ordinary skill in the art through
consideration of the following detailed description and the
accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] The drawings illustrate several embodiments of the
invention, wherein identical reference numerals refer to identical
elements or features in different views or embodiments shown in the
drawings.
[0015] FIG. 1 is a cross-sectional view of an embodiment of a PDC
including a PCD table having at least one low-carbon-solubility
material disposed therein.
[0016] FIG. 2 is a cross-sectional view of an assembly to be
processed under HPHT conditions to form the PDC shown in FIG. 1
according to an embodiment of method.
[0017] FIG. 3 is a cross-sectional view of an assembly to be HPHT
processed to form the PDC shown in FIG. 1 according to another
embodiment of method.
[0018] FIGS. 4A and 4B are cross-sectional views at different
stages during another embodiment of a method for fabricating the
PDC shown in FIG. 1.
[0019] FIG. 5A is an exploded isometric view of an assembly to be
HPHT processed to form a PDC including a PCD table that is
infiltrated with at least one low-carbon-solubility material in
selective locations according to an embodiment of method.
[0020] FIG. 5B is a cross-sectional view of the assembly shown in
FIG. 5A taken along line 5B-5B.
[0021] FIG. 5C is a cross-sectional view of the PDC formed by HPHT
processing the assembly shown in FIGS. 5A and 5B.
[0022] FIG. 5D is a top plan view of the infiltrated PCD table of
the PDC shown in FIG. 5C.
[0023] FIG. 5E is an exploded isometric view of an assembly to be
HPHT processed to form a PDC, which is similar to the assembly
shown in FIG. 5A, but the at least partially leached PCD table is
disposed between the thin ring of the at least one
low-carbon-solubility material and the substrate according to
another embodiment of method.
[0024] FIG. 6A is a cross-sectional view of an assembly to be HPHT
processed to form a PDC including a PCD table that is partially
infiltrated from a side thereof with at least one
low-carbon-solubility material according to another embodiment of
method.
[0025] FIG. 6B is a cross-sectional view of the PDC formed by HPHT
processing the assembly shown in FIG. 6A.
[0026] FIG. 6C is a cross-sectional view of an assembly to be HPHT
processed to form a PDC including a PCD table that is partially
infiltrated from the side with at least one low-carbon-solubility
material according to yet another embodiment of method.
[0027] FIG. 6D is a cross-sectional view of the PDC formed by HPHT
processing the assembly shown in FIG. 6C.
[0028] FIG. 6E is a cross-sectional view of an assembly to be HPHT
processed to form a PDC including a PCD table with a cap-like
structure including the at least one low-carbon-solubility material
therein according to an embodiment.
[0029] FIG. 6F is a cross-sectional view of the PDC formed by HPHT
processing the assembly shown in FIG. 6E.
[0030] FIG. 7A is a top plan view of an infiltrated PCD table of a
PDC that is selectively infiltrated with the at least one
low-carbon-solubility material in a plurality of discrete locations
according to an embodiment.
[0031] FIG. 7B is a top plan view of an infiltrated PCD table of a
PDC that is selectively infiltrated with the at least one
low-carbon-solubility material in a plurality of discrete locations
according to another embodiment.
[0032] FIG. 8A is a cross-sectional view of an assembly to be HPHT
processed to form the PDC shown in FIG. 1 in a single-step HPHT
process according to another embodiment of method.
[0033] FIG. 8B is a cross-sectional view of an assembly to be HPHT
processed to form the PDC shown in FIG. 1 in a single-step HPHT
process according to another embodiment of method.
[0034] FIG. 9 is an isometric view of an embodiment of a rotary
drill bit that may employ one or more of the disclosed PDC
embodiments.
[0035] FIG. 10 is a top elevation view of the rotary drill bit
shown in FIG. 9.
[0036] FIG. 11 is a bar chart showing the distance cut prior to
failure for the PDCs of working examples 1-13.
[0037] FIG. 12 is a scanning electron photomicrograph showing
copper (light regions) being extruded out of a copper-infiltrated
PCD table fabricated in accordance with working examples 4 and 5
during heating.
DETAILED DESCRIPTION
[0038] Embodiments of the invention relate to PDCs comprising a PCD
table including a thermally-stable region having at least one
low-carbon-solubility material disposed interstitially between
bonded diamond grains thereof, and methods of fabricating such
PDCs. The at least one low-carbon-solubility material exhibits a
melting temperature of about 1300.degree. C. or less and a bulk
modulus at 20.degree. C. of less than about 150 GPa. The at least
one low-carbon-solubility material, in combination with the high
diamond-to-diamond bond density of the diamond grains, may enable
the at least one low-carbon-solubility material to be extruded
between the diamond grains before causing the PCD table to fracture
during cutting operations as a result of interstitial stresses. As
such, the PCD table of the PDCs exhibits a high degree of damage
tolerance, wear resistance, and thermal stability. The PDCs
disclosed herein may be used in a variety of applications, such as
rotary drill bits, bearing apparatuses, wire-drawing dies,
machining equipment, and other articles and apparatuses.
[0039] FIG. 1 is a cross-sectional view of an embodiment of a PDC
100 including a PCD table 102 having at least one
low-carbon-solubility material disposed therein. The PCD table 102
includes a working upper surface 104, a generally opposing
interfacial surface 106, and at least one lateral surface 107
extending therebetween. It is noted that at least a portion of the
at least one lateral surface 107 may also function as a working
surface that contacts a subterranean formation during drilling.
Additionally, the PCD table 102 may include a chamfer that extends
about the upper surface 104 thereof or other edge geometry.
[0040] The interfacial surface 106 of the PCD table 102 is bonded
to a substrate 108. The substrate 108 may include, without
limitation, cemented carbides, such as tungsten carbide, titanium
carbide, chromium carbide, niobium carbide, tantalum carbide,
vanadium carbide, or combinations thereof cemented with a metallic
cementing constituent, such as iron, nickel, cobalt, or alloys
thereof. In an embodiment, the substrate 108 comprises
cobalt-cemented tungsten carbide. Although the interfacial surface
106 of the PCD table 102 is depicted in FIG. 1 as being
substantially planar, in other embodiments, the interfacial surface
106 may exhibit a selected nonplanar topography and the substrate
108 may exhibit a correspondingly configured interfacial
surface.
[0041] The PCD table 102 includes a plurality of directly
bonded-together diamond grains having diamond-to-diamond bonding
(e.g., sp.sup.3 bonding) therebetween. In an embodiment, the PCD
table 102 may be integrally formed on the substrate 108 (i.e.,
diamond particles are sintered on or near the substrate 108 to form
the PCD table 102). In another embodiment, the PCD table 102 is a
pre-sintered PCD table 102 that is infiltrated and attached to the
substrate 108. The plurality of bonded diamond grains define a
plurality of interstitial regions. The PCD table 102 includes a
thermally-stable first region 110 that may be remote from the
substrate 108 and extends inwardly from the upper surface 104 to a
depth "d" within the PCD table 102. As used herein, the phrase
"thermally-stable region" refers to a region of a PCD table that
exhibits a relatively increased thermal stability compared to one
or more other regions of the same PCD table. The first region 110
includes a first portion of the interstitial regions. A second
region 112 of the PCD table 102 adjacent to the substrate 108
includes a second portion of the interstitial regions.
[0042] At least a portion of the interstitial regions of the first
region 110 includes the at least one low-carbon-solubility material
disposed therein. For example, the at least one
low-carbon-solubility material is present in the first region 110
in an amount of about 1 weight % to about 10 weight %, about 2
weight % to about 10 weight %, about 3.5 weight % to about 8 weight
%, about 1 weight % to about 3 weight %, about 2.5 weight % to
about 6 weight %, or about 5 weight % to about 9 weight %, with the
balance substantially being diamond grains and residual
metal-solvent catalyst used in the sintering of the diamond grains
(if present). Several examples of low-carbon-solubility materials
will be discussed in more detail below. However, a
low-carbon-solubility material is a material, such as copper, tin,
aluminum, combinations thereof, or alloys thereof that does not
have a high solubility for carbon, generally does not effectively
catalyze growth of PCD, and is not a good carbide former. For
example, a low-carbon-solubility material has a maximum solubility
of carbon of less than about 0.1 weight % in its solid phase at
atmospheric-pressure. In a low-carbon-solubility material/carbon
chemical system having a eutectic point, a low-carbon-solubility
material has a maximum solubility of carbon of less than about 0.1
weight % in its solid phase at the atmospheric-pressure eutectic
temperature of the low-carbon-solubility material/carbon chemical
system. Cobalt, iron, nickel, silicon, and alloys comprising a
majority of at least one of cobalt, iron, nickel, or silicon are
examples of materials that are not low-carbon-solubility materials.
While the at least one low-carbon-solubility materials disclosed
herein may include small amounts of diamond catalytic metals (e.g.,
manganese, chromium, iron, nickel, cobalt, ruthenium, rhodium,
palladium, osmium, iridium, platinum, tantalum, combinations
thereof, and alloys thereof) and/or carbide forming elements (e.g.,
scandium, titanium, vanadium, yttrium, zirconium, niobium,
molybdenum, technetium, lanthanum, cerium, praseodymium, tungsten,
rhenium, thorium, uranium, plutonium, silicon, combinations
thereof, and alloys thereof), the concentration of such elements is
low enough so that the at least one low-carbon-solubility material
does not have a high solubility for carbon, still generally does
not effectively catalyze growth of PCD, and does not significantly
consume diamond during manufacture of the PCD table 102 by carbide
formation. However, in some embodiments, the at least one
low-carbon-solubility material is substantially free of diamond
catalytic metals (e.g., manganese, chromium, iron, nickel, cobalt,
ruthenium, rhodium, palladium, osmium, iridium, platinum, tantalum,
combinations thereof, and alloys thereof) and/or carbide forming
elements (e.g., scandium, titanium, vanadium, yttrium, zirconium,
niobium, molybdenum, technetium, lanthanum, cerium, praseodymium,
tungsten, rhenium, thorium, uranium, plutonium, silicon,
combinations thereof, and alloys thereof).
[0043] As the at least one low-carbon-solubility material may not
effectively catalyze PCD growth, the first region 110 is
thermally-stable and exhibits improved wear resistance and/or
thermal stability compared to if the first region 110 included a
solvent catalyst (e.g., cobalt) therein. When the PCD table 102 is
a pre-sintered PCD table, a residual amount of metallic catalyst
may also be present in the interstitial regions of the first region
110 and the second region 112 that was used to initially catalyze
formation of diamond-to-diamond bonding between the diamond grains
of the PCD table 102. The residual metallic catalyst may comprise
iron, nickel, cobalt, or alloys thereof. For example, the residual
metallic catalyst may be present in the PCD table 102 in amount of
about 2 weight % or less, about 0.8 weight % to about 1.50 weight
%, or about 0.86 weight % to about 1.47 weight %.
[0044] At least a portion of the interstitial regions of the second
region 112 includes a metallic constituent (e.g., the metallic
cementing constituent) disposed therein that may be provided and
infiltrated from the substrate 108. However, in other embodiments,
the metallic constituent may be provided from another source, such
as a thin disc of the metallic constituent or another source. For
example, the metallic constituent may comprise iron, nickel,
cobalt, or alloys thereof.
[0045] A nonplanar boundary 114 may be formed between the first
region 110 and the second region 112 of the PCD table 102. The
nonplanar boundary 114 exhibits a geometry characteristic of the
metallic constituent being only partially infiltrated into the
second region 112 of the PCD table 102. If the metallic constituent
had infiltrated the entire PCD table 102 so that the interstitial
regions of the first region 110 were also occupied by the metallic
constituent and subsequently removed in a leaching process to the
depth "d," a boundary between the first region 110 and the second
region 112 would be substantially planar and indicative of being
defined by a leaching process.
[0046] In an embodiment, the depth "d" to which the first region
110 extends may be almost the entire thickness of the PCD table
102. In another embodiment, the depth "d" may be an intermediate
depth within the PCD table 102 of about 50 .mu.m to about 500
.mu.m, about 200 .mu.m to about 400 .mu.m, about 300 .mu.m to about
450 .mu.m, about 0.2 mm to about 1.5 mm, about 0.5 mm to about 1.0
mm, about 0.65 mm to about 0.9 mm, or about 0.75 mm to about 0.85
mm. As the depth "d" of the first region 110 increases, the wear
resistance and/or thermal stability of the PCD table 102 may
increase.
[0047] The at least one low-carbon-solubility material of the first
region 110 of the PCD table 102 may be selected from a number of
different materials exhibiting a melting temperature of about
1300.degree. C. or less and a bulk modulus at 20.degree. C. of
about 150 GPa or less. As used herein, melting temperature refers
to the lowest temperature at which melting of a material begins at
standard pressure conditions (i.e., 100 kPa). For example,
depending upon the composition of the at least one
low-carbon-solubility material, the at least one
low-carbon-solubility material may melt over a temperature range
such as occurs when the at least one low-carbon-solubility material
is an alloy with a hypereutectic composition or a hypoeutectic
composition where melting begins at the solidus temperature and is
substantially complete at the liquidus temperature. In other cases,
the at least one low-carbon-solubility material may have a single
melting temperature as occurs in a substantially pure metal or a
eutectic alloy.
[0048] The at least one low-carbon-solubility material of the first
region 110 may be chosen from a number of different metals, alloys,
and semiconductors, such as copper, tin, indium, gadolinium,
germanium, gold, silver, aluminum, lead, zinc, cadmium, bismuth,
antimony, combinations thereof, and alloys thereof. In an
embodiment, the at least one low-carbon-solubility material may be
an alloy of copper and gold and/or silver to improve the corrosion
resistance of the at least one low-carbon-solubility material.
Thus, the at least one low-carbon-solubility material may be a
metallic, non-ceramic material. In one or more embodiments, the at
least one low-carbon-solubility material exhibits a coefficient of
thermal expansion of about 3.times.10.sup.-6 per .degree. C. to
about 20.times.10.sup.-6 per .degree. C., a melting temperature of
about 180.degree. C. to about 1300.degree. C., and a bulk modulus
at 20.degree. C. of about 30 GPa to about 150 GPa; a coefficient of
thermal expansion of about 15.times.10.sup.-6 per .degree. C. to
about 20.times.10.sup.-6 per .degree. C., a melting temperature of
about 180.degree. C. to about 1100.degree. C., and a bulk modulus
at 20.degree. C. of about 50 GPa to about 130 GPa; a coefficient of
thermal expansion of about 15.times.10.sup.-6 per .degree. C. to
about 20.times.10.sup.-6 per .degree. C., a melting temperature of
about 950.degree. C. to about 1100.degree. C. (e.g., 1090.degree.
C.), and a bulk modulus at 20.degree. C. of about 120 GPa to about
140 GPa (e.g., about 130 GPa); or a coefficient of thermal
expansion of about 15.times.10.sup.-6 per .degree. C. to about
20.times.10.sup.-6 per .degree. C., a melting temperature of about
180.degree. C. to about 300.degree. C. (e.g., about 250.degree.
C.), and a bulk modulus at 20.degree. C. of about 45 GPa to about
55 GPa (e.g., about 50 GPa). For example, the at least one
low-carbon-solubility material may exhibit a melting temperature of
less than about 1200.degree. C. (e.g., less than about 1100.degree.
C.) and a bulk modulus at 20.degree. C. of less than about 140 GPa
(e.g., less than about 130 GPa). For example, the at least one
low-carbon-solubility material may exhibit a melting temperature of
less than about 1200.degree. C. (e.g., less than 1100.degree. C.),
and a bulk modulus at 20.degree. C. of less than about 130 GPa.
[0049] With respect to some specific materials for the at least one
low-carbon-solubility material, for example, tin exhibits a
coefficient of thermal expansion of about 20.0.times.10.sup.-6 per
.degree. C., a melting temperature of about 232.degree. C., and a
bulk modulus at 20.degree. C. of about 52 GPa. For example, copper
exhibits a coefficient of thermal expansion of about
16.6.times.10.sup.-6 per .degree. C., a melting temperature of
about 1083.degree. C., and a bulk modulus at 20.degree. C. of about
130 GPa. For example, aluminum exhibits a coefficient of thermal
expansion of about 2.5.times.10.sup.-6 per .degree. C., a melting
temperature of about 658.degree. C., and a bulk modulus at
20.degree. C. of about 75 GPa. Of course, alloys of these metals
may also exhibit thermal expansion, melting temperature, and bulk
modulus values within the ranges disclosed above.
[0050] The strength of the diamond-to-diamond bonding between the
diamond grains of the PCD table 102 is sufficiently strong and the
density is sufficiently high so that the at least one
low-carbon-solubility material extrudes out of exposed interstitial
regions of the upper surface 104 and/or the at least one lateral
surface 107 of the PCD table 102 during heating thereof at a
temperature of at least about 0.6 times (e.g., about 0.6 to about
0.8 times) the absolute melting temperature of the at least one
low-carbon-solubility material at standard pressure (100 kPa)
without fracturing the PCD table 102. This is due to the relatively
low bulk modulus and melting temperature of the at least one
low-carbon-solubility material in combination with the high
strength and high density of the diamond-to-diamond bonds. In other
words, the at least one low-carbon-solubility material is not
capable of exerting sufficient thermal stresses on the surrounding
diamond grains to cause fracturing of the PCD table 102 and, thus,
is extruded out of the PCD table 102 instead of fracturing the PCD
table 102 during cutting operations.
[0051] In some embodiments, a selected portion of the at least one
low-carbon-solubility material may be at least partially removed
from a selected region of the PCD table 102 in a leaching process.
However, it should be noted that the inventors currently believe
that not removing any of the at least one low-carbon-solubility
material from the PCD table 102 may improve the impact resistance
of the PCD table 102 because the ductile at least one
low-carbon-solubility material may help arrest crack propagation
compared to if the at least one low-carbon-solubility material were
absent. A suitable acid (e.g., nitric acid, hydrochloric acid,
hydrofluoric acid, or mixtures thereof) or base may be used to
leach the selected portion of the at least one
low-carbon-solubility material from the selected region of the PCD
table 102. Even after leaching, a residual amount of the at least
one low-carbon-solubility material may be present in the PCD table
102 in an amount of about 0.8 weight % to about 1.50 weight %. As
an example, the leached selected region may extend inwardly from
the upper surface 104 and/or the at least one lateral surface 107
to a depth of about 50 .mu.m to about 700.mu.m, about 250 .mu.m to
about 400 .mu.m, about 250 .mu.m to about 350 .mu.m, about 250
.mu.m to about 300 .mu.m, about 250 .mu.m to about 275 .mu.m, or
about 500 .mu.m to about 1000 .mu.m.
[0052] FIG. 2 is a cross-sectional view of an assembly 200 to be
processed under HPHT conditions to form the PDC 100 shown in FIG. 1
according to an embodiment of a method. The assembly 200 includes
an at least partially leached PCD table 202 disposed between the
substrate 108 and at least one layer 204 including one or more of
the aforementioned low-carbon-solubility materials. The at least
partially leached PCD table 202 includes an upper surface 104' and
a back surface 106'. The at least partially leached PCD table 202
also includes a plurality of interstitial regions that were
previously completely occupied by a metallic catalyst and forms a
network of at least partially interconnected pores that extend
between the upper surface 104' and the back surface 106'.
[0053] The at least partially leached PCD table 202 and the at
least one layer 204 may be placed in a pressure transmitting medium
(e.g., a refractory metal can embedded in pyrophyllite or other
pressure transmitting medium) to form a cell assembly. The cell
assembly, including the at least partially leached PCD table 202
and the at least one layer 204, may be subjected to an HPHT process
using an ultra-high pressure press to create temperature and
pressure conditions at which diamond is stable. The temperature of
the HPHT process may be at least about 1000.degree. C. (e.g., about
1200.degree. C. to about 1600.degree. C., or about 1200.degree. C.
to about 1300.degree. C.) and the pressure of the HPHT process may
be at least 4.0 GPa (e.g., about 5.0 GPa to about 10.0 GPa, or
about 5.0 GPa to about 8.0 GPa) for a time sufficient to at least
partially melt and infiltrate the at least partially leached PCD
table 202 with the at least one low-carbon-solubility material from
the at least one layer 204 and the metallic cementing constituent
from the substrate 108. The at least one low-carbon-solubility
material is capable of infiltrating and/or wetting the diamond
grains to fill the interstitial regions between the bonded diamond
grains of the at least partially leached PCD table 202.
[0054] During the HPHT process, the at least one
low-carbon-solubility material from the at least one layer 204 at
least partially melts and infiltrates into a first region 110' of
the at least partially leached PCD table 202 prior to or
substantially simultaneously with the metallic cementing
constituent from the substrate 108 at least partially melting and
infiltrating into a second region 112' of the at least partially
leached PCD table 202 that is located adjacent to the substrate
108. The at least one low-carbon-solubility material from the at
least one layer 204 infiltrates into the first region 110' of the
at least partially leached PCD table 202 generally to the depth "d"
to fill at least a portion of the interstitial regions thereof. As
the at least one low-carbon-solubility material is not a strong
carbide former (e.g., silicon), the at least one
low-carbon-solubility material does not consume portions of the
diamond grains via a chemical reaction so that the strength of the
diamond grain structure may be preserved. It should also be noted
that the composition of the at least one low-carbon-solubility
material may change after infiltration. For example, if the at
least one low-carbon-solubility material includes a mixture of
copper and tin particles or discs, the copper and tin may form a
copper-tin alloy after HPHT processing and infiltration. As another
example, in some embodiments, when the at least one
low-carbon-solubility material is aluminum, the aluminum may
partially or substantially completely react with oxygen to form
aluminum oxide ("Al.sub.2O.sub.3") depending upon the atmosphere in
which the HPHT processing is conducted. The amount of the at least
one low-carbon-solubility material in the at least one layer 204
may be selected so that it only infiltrates into the first region
110' of the at least partially leached PCD table 202 to the depth
"d."
[0055] The HPHT conditions are also sufficient to at least
partially melt the metallic cementing constituent present in the
substrate 108 (e.g., cobalt in a cobalt-cemented tungsten carbide
substrate), which infiltrates into at least a portion of the
interstitial regions of the second region 112' of the at least
partially leached PCD table 202. However, the depth of infiltration
of the metallic cementing constituent from the substrate 108 may be
limited by the presence of the at least one low-carbon-solubility
material in the first region 110'. Upon cooling from the HPHT
process, the metallic cementing constituent infiltrated into the at
least partially leached PCD table 202 forms a strong metallurgical
bond between the second region 112' and the substrate 108.
[0056] Referring to FIG. 1 along with FIG. 2, in some embodiments,
the depth "d" extends the entire thickness of the PCD table 102 or
almost the entire thickness of the PCD table 102. However, the
metallic cementing constituent may form a strong metallurgical bond
between the substrate 108 and a portion of the diamond grains of
the second region 112 even when the metallic cementing constituent
is located just along or near the interface between the PCD table
102 and the substrate 108.
[0057] It should be noted that the thickness of the at least
partially leached PCD table 202 may be reduced after HPHT
processing. Before and/or after HPHT processing, the infiltrated
PCD table represented as the PCD table 102 shown in FIG. 1 may be
subjected to one or more types of finishing operations, such as
grinding, machining, or combinations of the foregoing.
[0058] The at least partially leached PCD table 202 shown in FIG. 2
may be fabricated by enclosing a plurality of diamond particles
with a metallic catalyst (e.g., cobalt, nickel, iron, or alloys
thereof) in a pressure transmitting medium (e.g., a refractory
metal can embedded in pyrophyllite or other pressure transmitting
medium) to form a cell assembly and subjecting the cell assembly
including the contents therein to an HPHT sintering process to
sinter the diamond particles and form a PCD body comprised of
bonded diamond grains that exhibit diamond-to-diamond bonding
(e.g., sp.sup.3 bonding) therebetween. For example, the metallic
catalyst may be mixed with the diamond particles, infiltrated from
a metallic catalyst foil or powder adjacent to the diamond
particles, provided and infiltrated from a cemented carbide
substrate (e.g., cobalt from a cobalt cemented tungsten carbide
substrate), or combinations of the foregoing. The bonded diamond
grains define interstitial regions, with the metallic catalyst
disposed within at least a portion of the interstitial regions. The
diamond particles may exhibit a single-mode diamond particle size
distribution, or a bimodal or greater diamond particle size
distribution. The as-sintered PCD body may be leached by immersion
in an acid, such as aqua regia, nitric acid, hydrofluoric acid,
mixtures of the foregoing, or subjected to another suitable process
to remove at least a portion of the metallic catalyst from the
interstitial regions of the PCD body and form the at least
partially leached PCD table 202. For example, the as-sintered PCD
body may be immersed in the acid for about 2 to about 7 days (e.g.,
about 3, 5, or 7 days) or for a few weeks (e.g., about 4 weeks)
depending on the process employed. It is noted that when the
metallic catalyst is infiltrated into the diamond particles from a
cemented tungsten carbide substrate including tungsten carbide
particles cemented with a metallic catalyst (e.g., cobalt, nickel,
iron, or alloys thereof), the infiltrated metallic catalyst may
carry a tungsten-containing material (e.g., tungsten and/or
tungsten carbide) therewith and the as-sintered PCD body may
include such tungsten-containing material therein disposed
interstitially between the bonded diamond grains. Depending upon
the leaching process, at least a portion of the tungsten-containing
material may not be substantially removed by the leaching process
and may enhance the wear resistance of the at least partially
leached PCD table 202.
[0059] The diamond-stable HPHT sintering process conditions
employed to form the as-sintered PCD body may be a temperature of
at least about 1000.degree. C. (e.g., about 1100.degree. C. to
about 2200.degree. C., or about 1200.degree. C. to about
1450.degree. C.) and a pressure in the pressure transmitting medium
of at least about 7.5 GPa (e.g., about 7.5 GPa to about 15 GPa,
about 9 GPa to about 12 GPa, or about 10 GPa to about 12.5 GPa) for
a time sufficient to sinter the diamond particles together in the
presence of the metallic catalyst and form the PCD comprising
directly bonded-together diamond grains defining interstitial
regions occupied by the metal-solvent catalyst. For example, the
pressure in the pressure transmitting medium that encloses the
diamond particles and metallic catalyst source may be at least
about 8.0 GPa, at least about 9.0 GPa, at least about 10.0 GPa, at
least about 11.0 GPa, at least about 12.0 GPa, or at least about 14
GPa.
[0060] As the sintering pressure employed during the HPHT process
used to fabricate the PCD body is moved further into the
diamond-stable region away from the graphite-diamond equilibrium
line, the rate of nucleation and growth of diamond increases. Such
increased nucleation and growth of diamond between diamond
particles (for a given diamond particle formulation) may result in
the as-sintered PCD body being formed that exhibits one or more of
a relatively lower metallic catalyst content, a higher coercivity,
a lower specific magnetic saturation, or a lower specific
permeability (i.e., the ratio of specific magnetic saturation to
coercivity) than PCD formed at a lower sintering pressure.
[0061] Generally, as the sintering pressure that is used to form
the PCD body increases, the coercivity of the PCD body may increase
and the magnetic saturation may decrease. The PCD body defined
collectively by the bonded diamond grains and the metallic catalyst
may exhibit a coercivity of about 115 Oersteds ("Oe") or more and a
metallic catalyst content of less than about 7.5 weight % ("wt %")
as indicated by a specific magnetic saturation of about 15
Gausscm.sup.3/grams ("Gcm.sup.3/g") or less. For example, the
coercivity of the PCD body may be about 115 Oe to about 250 Oe and
the specific magnetic saturation of the PCD body may be greater
than 0 Gcm.sup.3/g to about 15 Gcm.sup.3/g. In an even more
detailed embodiment, the coercivity of the PCD body may be about
115 Oe to about 175 Oe and the specific magnetic saturation of the
PCD body may be about 5 G.sup.3/g to about 15 G.sup.3/g. In yet an
even more detailed embodiment, the coercivity of the PCD body may
be about 155 Oe to about 175 Oe and the specific magnetic
saturation of the PCD body may be about 10 Gcm.sup.3/g to about 15
G.sup.3/g. The specific permeability (i.e., the ratio of specific
magnetic saturation to coercivity) of the PCD may be about 0.10 or
less, such as about 0.060 Gcm.sup.3/Oeg to about 0.090
Gcm.sup.3/Oeg.
[0062] As merely one example, ASTM B886-03 (2008) provides a
suitable standard for measuring the specific magnetic saturation
and ASTM B887-03 (2008) e1 provides a suitable standard for
measuring the coercivity of the PCD. Although both ASTM B886-03
(2008) and ASTM B887-03 (2008) e1 are directed to standards for
measuring magnetic properties of cemented carbide materials, either
standard may be used to determine the magnetic properties of PCD. A
KOERZIMAT CS 1.096 instrument (commercially available from Foerster
Instruments of Pittsburgh, Pa.) is one suitable instrument that may
be used to measure the specific magnetic saturation and the
coercivity of the PCD.
[0063] The pressure values employed in the HPHT processes disclosed
herein refer to the pressure in the pressure transmitting medium at
room temperature (e.g., about 25.degree. C.) with application of
pressure using an ultra-high pressure press and not the pressure
applied to the exterior of the cell assembly. The actual pressure
in the pressure transmitting medium at sintering temperature may be
slightly higher. The ultra-high pressure press may be calibrated at
room temperature by embedding at least one calibration material
that changes structure at a known pressure such as, PbTe, thallium,
barium, or bismuth in the pressure transmitting medium.
[0064] Even after leaching, a residual amount of the metallic
catalyst may remain in the interstitial regions between the bonded
diamond grains of the at least partially leached PCD table 202 that
may be identifiable using mass spectroscopy, energy dispersive
x-ray spectroscopy microanalysis, or other suitable analytical
technique. Such entrapped, residual metallic catalyst is difficult
to remove even with extended leaching times. For example, the
residual amount of metallic catalyst may be present in an amount of
about 4 weight % or less, about 3 weight % or less, about 2 weight
% or less, about 0.8 weight % to about 1.50 weight %, or about 0.86
weight % to about 1.47 weight %.
[0065] The at least partially leached PCD table 202 may be
subjected to at least one shaping process prior to bonding to the
substrate 108, such as grinding or lapping, to tailor the geometry
thereof (e.g., forming an edge chamfer), as desired, for a
particular application. The as-sintered PCD body may also be shaped
prior to leaching or bonding to the substrate 108 by a machining
process, such as electro-discharge machining
[0066] The plurality of diamond particles sintered to form the at
least partially leached PCD table 202 may exhibit one or more
selected sizes. The one or more selected sizes may be determined,
for example, by passing the diamond particles through one or more
sizing sieves or by any other method. In an embodiment, the
plurality of diamond particles may include a relatively larger size
and at least one relatively smaller size. As used herein, the
phrases "relatively larger" and "relatively smaller" refer to
particle sizes determined by any suitable method, which differ by
at least a factor of two (e.g., 40 .mu.m and 20 .mu.m). More
particularly, in various embodiments, the plurality of diamond
particles may include a portion exhibiting a relatively larger size
(e.g., 100 .mu.m, 90 .mu.m, 80 .mu.m, 70 .mu.m, 60 .mu.m, 50 .mu.m,
40 .mu.m, 30 .mu.m, 20 .mu.m, 15 .mu.m, 12 .mu.m, 10 .mu.m, 8
.mu.m) and another portion exhibiting at least one relatively
smaller size (e.g., 30 .mu.m, 20 .mu.m, 10 .mu.m, 15 .mu.m, 12
.mu.m, 10 .mu.m, 8 .mu.m, 4 .mu.m, 2 .mu.m, 1 .mu.m, 0.5 .mu.m,
less than 0.5 .mu.m, 0.1 .mu.m, less than 0.1 .mu.m). In another
embodiment, the plurality of diamond particles may include a
portion exhibiting a relatively larger size between about 40 .mu.m
and about 15 .mu.m and another portion exhibiting a relatively
smaller size between about 12 .mu.m and about 2 .mu.m. Of course,
the plurality of diamond particles may also comprise three or more
different sizes (e.g., one relatively larger size and two or more
relatively smaller sizes), without limitation.
[0067] It should be noted that the second region 112 of the PCD
table 102 in FIG. 1 may exhibit any of the foregoing magnetic
characteristics as at least a portion of the interstitial regions
thereof are occupied by a ferromagnetic metallic constituent, such
as cobalt from the substrate 108. The high coercivity is indicative
of the high strength and density of the diamond-to-diamond bonds
between the diamond grains of the PCD table 102. The low magnetic
saturation is indicative of a low metallic catalyst content of
about 1 wt % to about 7.5 wt %, such as about 3 wt % to about 6 wt
%. The magnetic characteristics of the second region 112 may be
determined by removing the substrate 108 and the first region 110
via grinding, electro-discharge machining, or another suitable
material removal process and magnetically testing the isolated
second region 112 of the PCD table 102.
[0068] FIG. 3 is a cross-sectional view of an assembly 300 to be
HPHT processed to form the PDC shown in FIG. 1 according to another
embodiment of method. The at least one layer 204 including the at
least one low-carbon-solubility material therein may be positioned
between the at least partially leached PCD table 202 and the
substrate 108 to form the assembly 300. The assembly 300 may be
enclosed in a suitable pressure transmitting medium and subjected
to an HPHT process to form the PDC 100 (FIG. 1) using the same or
similar HPHT conditions previously discussed with respect to HPHT
processing the assembly 200 shown in FIG. 2.
[0069] FIGS. 4A and 4B are cross-sectional views at different
stages during another embodiment of a method for fabricating the
PDC 100 shown in FIG. 1. Referring to FIG. 4A, the at least
partially leached PCD table 202 may be provided that includes the
upper surface 104' and the back surface 106'. The least one layer
204 including the at least one low-carbon-solubility material
therein may be positioned adjacent to the upper surface 104' to
form the assembly 400, such as by coating the upper surface 104'
with the at least one layer 204 and/or disposing the at least one
layer 204 in the bottom of a container and placing the at least
partially leached PCD table 202 in the container and in contact
with the at least one layer 204.
[0070] The assembly 400 may be enclosed in a suitable pressure
transmitting medium to form a cell assembly and subjected to an
HPHT process using the HPHT conditions used to HPHT process the
assembly 200 shown in FIG. 2. During the HPHT process, the at least
one low-carbon-solubility material of the at least one layer 204
may partially or substantially completely melt and infiltrate into
at least a portion of the interstitial regions of the first region
110' of the at least partially leached PCD table 202 to form a
partially infiltrated PCD table 202' (FIG. 4B). The volume of the
at least one low-carbon-solubility material may be selected so that
it is sufficient to only fill the interstitial regions of the
selected first region 110'. Thus, the interstitial regions of the
second region 112' are not infiltrated with the at least one
low-carbon-solubility material and, thus, are substantially free of
the at least one low-carbon-solubility material.
[0071] In another embodiment, when the at least one
low-carbon-solubility material in the at least one layer 204 melts
or begins melting at a sufficiently low temperature so the
infiltration can be performed without significantly damaging the
diamond grains of the at least partially leached PCD table 202, the
at least one low-carbon-solubility material may be infiltrated into
the at least partially leached PCD table 202 under atmospheric
pressure conditions or in a hot-isostatic pressing ("HIP") process.
For example, one suitable at least one low-carbon-solubility
material may comprise a eutectic or near eutectic (e.g.,
hypereutectic or hypoeutectic) mixture or alloy of aluminum and
silicon.
[0072] Referring to FIG. 4B, the back surface 106' of the partially
infiltrated PCD table 202' may be positioned adjacent to the
substrate 108 to form an assembly 402. The assembly 402 may be
subjected to an HPHT process using the HPHT conditions used to HPHT
process the assembly 200 shown in FIG. 2. During the HPHT process,
the metallic cementing constituent present in the substrate 108 may
liquefy, and infiltrate into and occupy at least a portion of the
interstitial regions of the second region 112'. Upon cooling from
the HPHT process, the metallic cementing constituent forms a strong
metallurgical bond between the substrate 108 and the second region
112'.
[0073] In other embodiments, the at least partially leached PCD
table 202 may be selectively infiltrated with at least one
low-carbon-solubility material to provide a thermally-stable
cutting edge region while a metallic constituent may be infiltrated
in other regions of the at least partially leached PCD table 202 to
provide a strong bond with the substrate 108. FIGS. 5A and 5B are
exploded isometric and cross-sectional views of an assembly 500 to
be HPHT processed to form a PDC including a PCD table that is
infiltrated with at least one low-carbon-solubility material in
selective locations according to an embodiment of method. The
assembly 500 includes a thin ring 502 or other annular structure
made from one or more of the low-carbon-solubility materials
disclosed herein. The thin ring 502 is disposed between the at
least partially leached PCD table 202 and the substrate 108.
However, in another embodiment shown in FIG. 5E, the at least
partially leached PCD table 202 may be disposed between the thin
ring 502 and the substrate 108. The assembly 500 may be subjected
to an HPHT process using the same or similar HPHT conditions used
to process the assembly 200 shown in FIG. 2.
[0074] FIG. 5C is a cross-sectional view of a PDC 504 formed by
HPHT processing the assembly 500 and FIG. 5D is a top plan view.
During the HPHT process, the thin ring 502 liquefies and
infiltrates into a generally annular region 506 (FIG. 5B) of the at
least partially leached PCD table 202. During the HPHT process, a
metallic cementing constituent (e.g., cobalt) from the substrate
108 also infiltrates into a core region 508 (FIG. 5B) of the at
least partially leached PCD table 202. In some embodiments, the
thin ring 502 liquefies before the metallic cementing constituent
and, thus, the metallic cementing constituent infiltrates the core
region 508 after the at least one low-carbon-solubility material
infiltrates into the generally annular region 506. However, in
other embodiments, the metallic cementing constituent may
infiltrate at substantially the same time as the at least one
low-carbon-solubility material. The infiltrated metallic cementing
constituent provides a strong metallurgical bond between a PCD
table 510 so-formed and the substrate 108. The PCD table 510
so-formed includes a thermally-stable cutting region 512 exhibiting
a generally annular configuration that includes the infiltrated at
least one low-carbon-solubility material provided from the thin
ring 502, and a core region 514 that includes the infiltrated
metallic cementing constituent.
[0075] Referring to FIG. 6A, in other embodiments, the at least
partially leached PCD table 202 may be infiltrated with the at
least one low-carbon-solubility material from at least one lateral
surface 600 thereof. In such an embodiment, a ring 602 may be
disposed about the at least partially leached PCD table 202, and
the assembly of the ring 602 and the at least partially leached PCD
table 202 may be positioned adjacent to the interfacial surface 106
of the substrate 108 to form an assembly 604. The assembly 604 may
be subjected to an HPHT process using the same or similar HPHT
conditions used to process the assembly 200 shown in FIG. 2.
[0076] During the HPHT process, the ring 602 liquefies and
infiltrates through the at least one lateral surface 600 and into a
generally annular region 604 of the at least partially leached PCD
table 202. During the HPHT process, a metallic cementing
constituent from the substrate 108 also infiltrates into a core
region 606 of the at least partially leached PCD table 202. In some
embodiments, the ring 602 liquefies before the metallic cementing
constituent and, thus, the metallic cementing constituent
infiltrates the core region 606 after the at least one
low-carbon-solubility material infiltrates into the generally
annular region 604. However, in other embodiments, the metallic
cementing constituent may infiltrate at substantially the same time
as the at least one low-carbon-solubility material.
[0077] Referring to FIG. 6B, the infiltrated metallic cementing
constituent provides a strong metallurgical bond between a PCD
table 608 so-formed and the substrate 108. The PCD table 608
so-formed includes a thermally-stable cutting region 610 exhibiting
a generally annular configuration that includes the infiltrated at
least one low-carbon-solubility material provided from the ring
602, and a core region 611 including the infiltrated metallic
cementing constituent.
[0078] Referring to FIG. 6C, in some embodiments, the ring 602 may
exhibit a thickness T1 that is dimensioned to be less than that of
a thickness T2 of the at least partially leached PCD table 202.
Referring to FIG. 6D, after HPHT process of the assembly shown in
FIG. 6C, a PCD table 608' so-formed includes a thermally-stable
cutting region 610' that does not extend the total thickness T2 of
the PCD table 608'. Rather, the thermally-stable cutting region
610' only extends part of the thickness of the PCD table 608' and
has a standoff 612 from the interfacial surface 106 of the
substrate 108.
[0079] In other embodiments, a cap-like structure including the at
least one low-carbon-solubility material may be formed. Referring
to FIG. 6E, a receptacle 602' made from the at least one
low-carbon-solubility material may be placed over the upper surface
104' of the at least partially leached PCD table 202. As shown in
FIG. 6F, after HPHT processing, the at least one
low-carbon-solubility material infiltrates the at least partially
leached PCD table 202 to form a cap-like structure 614 that extends
along an upper surface 616 and lateral surface 618 of infiltrated
PCD table 620 so-formed. Depending upon the geometry of the
receptacle 602', the cap-like structure 614 may extend along only
part of the length of the lateral surface 618 or along
substantially the entire length of the lateral surface 618 so that
there is no standoff from the interfacial surface 106 of the
substrate 108 to which the infiltrated PCD table 620 is bonded.
[0080] A variety of other thermally-stable cutting region
configurations may be formed besides those illustrated in FIGS. 5C,
6B, and 6D. FIG. 7A is a top plan view of a PCD table 700 that is
selectively infiltrated with the at least one low-carbon-solubility
material in multiple discrete locations to form a plurality of
thermally-stable cutting regions 702 according to another
embodiment. A main region 704 may be infiltrated with a metallic
cementing constituent from the substrate 108 (not shown). The
plurality of thermally-stable cutting regions 702 may be formed,
for example, by dividing the thin ring 502 (FIGS. 5A and 5B) into
discrete sections that are placed between the at least partially
leached PCD table 202 and the substrate 108 and circumferentially
spaced from each other. Alternatively, the discrete sections may be
placed adjacent to an upper surface of the at least partially
leached PCD table 202.
[0081] FIG. 7B is a top plan view of an infiltrated PCD table 706
that is selectively infiltrated with the at least one
low-carbon-solubility material in multiple discrete locations to
form a plurality of thermally-stable cutting regions 708 according
to another embodiment. The plurality of thermally-stable cutting
regions 708 are interconnected by a network of radially-extending
branches 710. A region 712 extending about the plurality of
thermally-stable cutting regions 708 and the branches 710 may be
infiltrated with a metallic cementing constituent from the
substrate 108 (not shown). The plurality of thermally-stable
cutting regions 708 and the branches 710 may be formed by cutting,
stamping, or machining a substantially correspondingly shaped
structure from a thin disc made from the at least one
low-carbon-solubility material.
[0082] In other embodiments, the PCD table 102 of the PDC 100 may
be integrally formed with the substrate 108 in a single-step HPHT
process. For example, FIG. 8A is a cross-sectional view of an
assembly 800 to be processed under HPHT conditions to form the PDC
100 shown in FIG. 1 in a single-step HPHT process according to an
embodiment of a method. The assembly 800 includes a plurality of
diamond particles 802 positioned between the substrate 108 and a
carbon source 804. The plurality of diamond particles 802 may
exhibit any of the diamond particle sizes and distributions
disclosed herein.
[0083] The carbon source 804 includes one or more of the at least
one low-carbon-solubility materials implanted with carbon ions. In
an embodiment, the carbon source 804 includes a thin disc of one or
more of the at least one low-carbon-solubility materials implanted
with carbon ions. In another embodiment, the carbon source 804
includes a plurality of particles made from one or more of the at
least one low-carbon-solubility materials implanted with carbon
ions. For example, the plurality of particles may be made from the
same low-carbon-solubility material or a mixture of two or more
types of particles made from different types of
low-carbon-solubility materials.
[0084] The carbon source 804 may be formed by directing a plurality
of carbon ions at the one or more of the at least one
low-carbon-solubility materials to implant the carbon ions therein.
The dose and implantation energy of the carbon ions implanted may
be sufficient to at least saturate or supersaturate the one or more
of the at least one low-carbon-solubility materials with the carbon
ions. As disclosed herein, the solubility of carbon in the at least
one low-carbon-solubility material may be very low at room
temperature. Therefore, the carbon ions may be in solution in the
one or more of the at least one low-carbon-solubility materials in
a metastable state.
[0085] In an embodiment, a plasma that includes the carbon ions may
be generated from a carbon-containing gas using electron cyclotron
resonance ("ECR"), a large-area pulsed radio frequency, or another
suitable technique. For example, the carbon ions may be generated
by discharge of a carbon-containing gas, such as carbon monoxide,
carbon dioxide, methane, another type of hydrocarbon gas, or
mixtures of the foregoing; or sputter erosion of carbon electrode
using a plasma, such as an argon plasma. The carbon ions may be
accelerated at the one or more of the at least one
low-carbon-solubility materials using a high-voltage source so that
the carbon ions become embedded therein. For example, the carbon
ions may be accelerated at the one or more of the at least one
low-carbon-solubility materials with an energy of about 2 keV to
about 50 keV. In some embodiments, the carbon ions may be in the
form of a high-energy beam of carbon ions that may be directed at
the one or more of the at least one low-carbon-solubility
materials. For example, the high-energy beam of carbon ions may
exhibit an energy of about 70 keV to about 100 keV. The dose of the
carbon ions implanted into the one or more of the at least one
low-carbon-solubility materials may be about 10.sup.15 ions per
cm.sup.2 to about 10.sup.18 ions per cm.sup.2, such as about 10
.sup.16 ions per cm.sup.2 to about 10.sup.17 ions per cm.sup.2 or
about 10.sup.17 ions per cm.sup.2 or more. In an embodiment, the
one or more of the at least one low-carbon-solubility materials may
be implanted with carbon ions in sequentially applied doses each of
which has a lower implantation energy to thereby stack the carbon
ions.
[0086] The assembly 800 may be placed in a pressure transmitting
medium, such as a refractory metal can embedded in pyrophyllite or
other pressure transmitting medium, to form a cell assembly. The
cell assembly, including the assembly 800 therein, may be subjected
to an HPHT process using an ultra-high pressure press to create
temperature and pressure conditions at which diamond is stable. The
temperature of the HPHT process may be at least about 1000.degree.
C. (e.g., about 1200.degree. C. to about 1600.degree. C., or about
1200.degree. C. to about 1300.degree. C.) and the pressure of the
HPHT process may be at least 4.0 GPa (e.g., about 5.0 GPa to about
10.0 GPa, or about 5.0 GPa to about 8.0 GPa) for a time sufficient
to at least partially melt and infiltrate the plurality of diamond
particles 802 with the one or more of the at least one
low-carbon-solubility materials implanted with carbon ions from the
carbon source 804 and the metallic cementing constituent from the
substrate 108.
[0087] During the HPHT process, the one or more of the at least one
low-carbon-solubility materials implanted with carbon ions from the
carbon source 804 at least partially melts and infiltrates into a
first region 110''of the plurality of diamond particles 802
carrying carbon prior to or substantially simultaneously with the
metallic cementing constituent from the substrate 108 infiltrating
into a second region 112'' of the plurality of diamond particles
802 that is located adjacent to the substrate 108. The one or more
of the at least one low-carbon-solubility materials from the carbon
source 804 infiltrates into the plurality of diamond particles 802
generally to a selected depth and the implanted carbon ions
precipitate as diamond under the diamond-stable HPHT conditions.
Thus, the one or more of the at least one low-carbon-solubility
materials implanted with carbon ions may carry such carbon ions
that precipitate to form diamond-to-diamond bonds between the
plurality of diamond particles 802 to form first region 110 of the
sintered PCD table 102 (FIG. 1). The amount of the at least one
low-carbon-solubility material in the carbon source 804 may be
selected so that it only infiltrates into the first region 110'' to
the selected depth. The HPHT conditions are also sufficient to at
least partially melt the metallic cementing constituent present in
the substrate 108 (e.g., cobalt in a cobalt-cemented tungsten
carbide substrate), which infiltrates into the interstitial regions
of the second region 112'' of the plurality of diamond particles
802 to catalyze formation of PCD therefrom. However, the depth of
infiltration of the metallic cementing constituent from the
substrate 108 may be limited by the presence of the at least one
low-carbon-solubility material in the first region 110''. Upon
cooling from the HPHT process, the infiltrated metallic cementing
constituent forms a strong metallurgical bond between the PCD table
102 (FIG. 1) so-formed and the substrate 108.
[0088] In another embodiment, the carbon source 804 may be
positioned between the substrate 108 and the plurality of diamond
particles 802 to form an assembly. The assembly so-formed may be
enclosed in a suitable pressure transmitting medium to form a cell
assembly and subjected to an HPHT process to form the PDC 100 (FIG.
1) using the same or similar HPHT conditions previously discussed
with respect to HPHT processing the assembly 800 shown in FIG.
8A.
[0089] FIG. 8B is a cross-sectional view of an assembly 806 to be
processed under HPHT conditions to form the PDC 100 shown in FIG. 1
in a single-step HPHT process according to an embodiment of a
method. The assembly 806 includes a mixture of diamond particles
810 and carbon-source particles 812 made from at least one
low-carbon-solubility material implanted with carbon ions. For
example, the diamond particles 810 may exhibit any of the disclosed
diamond particle size and distributions disclosed herein and the at
least one low-carbon-solubility material may be chosen from any of
the at least one low-carbon-solubility materials disclosed herein
or combinations thereof. The carbon-source particles 812 may be
formed by implanting particles made from the at least one
low-carbon-solubility material with carbon ions using any of the
implantation techniques disclosed herein. The assembly 806 may be
enclosed in a suitable pressure transmitting medium and subjected
to an HPHT process to form the PDC 100 (FIG. 1) using the same or
similar HPHT conditions previously discussed with respect to HPHT
processing the assembly 800 shown in FIG. 8A.
[0090] FIG. 9 is an isometric view and FIG. 10 is a top elevation
view of an embodiment of a rotary drill bit 900 that includes at
least one PDC configured and/or made according to any of the
disclosed PDC embodiments. The rotary drill bit 900 includes a bit
body 902 that includes radially and longitudinally extending blades
904 having leading faces 906, and a threaded pin connection 908 for
connecting the bit body 902 to a drilling string. The bit body 902
defines a leading end structure for drilling into a subterranean
formation by rotation about a longitudinal axis 910 and application
of weight-on-bit. At least one PDC, configured and/or made
according to any of the disclosed PDC embodiments, may be affixed
to the bit body 902. With reference to FIG. 10, each of a plurality
of PDCs 912 are secured to the blades 904 of the bit body 902 (FIG.
9). For example, each PDC 912 may include a PCD table 914 bonded to
a substrate 916. More generally, the PDCs 912 may comprise any PDC
disclosed herein, without limitation. In addition, if desired, in
some embodiments, a number of the PDCs 912 may be conventional in
construction. Also, circumferentially adjacent blades 904 define
so-called junk slots 920 therebetween. Additionally, the rotary
drill bit 900 includes a plurality of nozzle cavities 918 for
communicating drilling fluid from the interior of the rotary drill
bit 900 to the PDCs 912.
[0091] FIGS. 9 and 10 merely depict one embodiment of a rotary
drill bit that employs at least one PDC fabricated and structured
in accordance with the disclosed embodiments, without limitation.
The rotary drill bit 900 is used to represent any number of
earth-boring tools or drilling tools, including, for example, core
bits, roller-cone bits, fixed-cutter bits, eccentric bits, bicenter
bits, reamers, reamer wings, or any other downhole tool including
superabrasive compacts, without limitation.
[0092] The PDCs disclosed herein (e.g., PDC 100 of FIG. 1) may also
be utilized in applications other than cutting technology. For
example, the disclosed PDC embodiments may be used in wire dies,
bearings, artificial joints, inserts, cutting elements, and heat
sinks. Thus, any of the PDCs disclosed herein may be employed in an
article of manufacture including at least one superabrasive element
or compact.
[0093] Thus, the embodiments of PDCs disclosed herein may be used
in any apparatus or structure in which at least one conventional
PDC is typically used. In one embodiment, a rotor and a stator,
assembled to form a thrust-bearing apparatus, may each include one
or more PDCs (e.g., PDC 100 of FIG. 1) configured according to any
of the embodiments disclosed herein and may be operably assembled
to a downhole drilling assembly. U.S. Pat. Nos. 4,410,054;
4,560,014; 5,364,192; 5,368,398; and 5,480,233, the disclosure of
each of which is incorporated herein, in its entirety, by this
reference, disclose subterranean drilling systems within which
bearing apparatuses utilizing superabrasive compacts disclosed
herein may be incorporated. The embodiments of PDCs disclosed
herein may also form all or part of heat sinks, wire dies, bearing
elements, cutting elements, cutting inserts (e.g., on a
roller-cone-type drill bit), machining inserts, or any other
article of manufacture as known in the art. Other examples of
articles of manufacture that may use any of the PDCs disclosed
herein are disclosed in U.S. Pat. Nos. 4,811,801; 4,268,276;
4,468,138; 4,738,322; 4,913,247; 5,016,718; 5,092,687; 5,120,327;
5,135,061; 5,154,245; 5,180,022; 5,460,233; 5,544,713; and
6,793,681, the disclosure of each of which is incorporated herein,
in its entirety, by this reference.
[0094] The following working examples set forth various
formulations and methods for forming PDCs. In the following working
examples, the thermal stability of conventional comparative working
examples 1 through 3 are compared to the thermal stability of
working examples 4 through 13 according to embodiments of the
invention.
COMPARATIVE EXAMPLES 1 AND 2
[0095] Two conventional PDCs were obtained that were fabricated by
placing a layer of diamond particles having an average particle
size of about 19 .mu.m adjacent to a cobalt-cemented tungsten
carbide substrate. The layer and substrate were placed in a
container assembly. The container assembly, including the layer and
substrate therein, were subjected to HPHT conditions in an HPHT
press at a temperature of about 1400.degree. C. and a pressure of
about 5 GPa to about 8 GPa to form a conventional PDC including a
PCD table integrally formed and bonded to the cobalt-cemented
tungsten carbide substrate. Cobalt was infiltrated into the layer
of diamond particles from the cobalt-cemented tungsten carbide
substrate catalyzing formation of the PCD table. The nominal
thickness of the PCD table of the PDC was about 2.286 mm and an
about 45 degree, 0.3048-mm nominal chamfer was machined in the PCD
table.
[0096] The thermal stability of the PCD table of comparative
examples 1 and 2 was evaluated by measuring the distance cut in a
Barre granite workpiece prior to failure, without using coolant, in
a vertical turret lathe test. The distance cut is considered
representative of the thermal stability of the PCD table. The test
parameters were a depth of cut for the PDC of about 1.27 mm, a back
rake angle for the PDC of about 20 degrees, an in-feed for the PDC
of about 1.524 mm/rev, a cutting speed of the workpiece to be cut
of about 1.78 m/sec, and the workpiece had an outer diameter of
about 914 mm and an inner diameter of about 254 mm. The
conventional PCD tables of the PDCs of comparative examples 1 and 2
were able to cut a distance of about 2576 and 3308 linear feet,
respectively, in the workpiece prior to failure.
COMPARATIVE EXAMPLE 3
[0097] A PDC was obtained, which was fabricated as performed in
comparative examples 1 and 2. The nominal thickness of the PCD
table of the PDC was about 2.286 mm and an about 45 degree,
0.3048-mm nominal chamfer was machined in the PCD table. Then, the
PCD table was acid leached after machining to a depth of about 200
.mu.m.
[0098] The thermal stability of the PCD table of comparative
example 3 was evaluated by measuring the distance cut prior to
failure in the same workpiece used to test comparative examples 1
and 2 and using the same test parameters, without using coolant, in
a vertical turret lathe test. The conventional PCD table of the PDC
of comparative example 3 was able to cut a distance of about 4933
linear feet in the workpiece prior to failure.
EXAMPLES 4 AND 5
[0099] Two PDCs were formed according to the following process. A
PCD table was formed by HPHT sintering, in the presence of cobalt,
diamond particles having an average grain size of about 19 .mu.m.
The PCD table included bonded diamond grains, with cobalt disposed
within interstitial regions between the bonded diamond grains. The
PCD table was leached with acid for a time sufficient to remove
substantially all of the cobalt from the interstitial regions to
form an at least partially leached PCD table. The at least
partially leached PCD table was placed adjacent to a
cobalt-cemented tungsten carbide substrate. A layer of copper was
placed adjacent to the at least partially leached PCD table on a
side thereof opposite the cobalt-cemented tungsten carbide
substrate. The at least partially leached PCD table,
cobalt-cemented tungsten carbide substrate, and layer of copper
were placed in a container assembly and HPHT processed in a
high-pressure cubic press at a temperature of about 1400.degree. C.
and a pressure of about 5 GPa to about 8 GPa to form a PDC
comprising an infiltrated PCD table bonded to the cobalt-cemented
tungsten carbide substrate. During the HPHT process, copper from
the layer of copper infiltrated an upper region of the PCD table
and cobalt from the cobalt-cemented tungsten carbide substrate
infiltrated a lower region of the PCD table adjacent the
cobalt-cemented tungsten carbide substrate. The copper-infiltrated
PCD table had a thickness of about 2.286 mm and an about 45 degree,
0.3048-mm nominal chamfer was machined in the infiltrated PCD
table.
[0100] FIG. 11 is a bar chart showing the distance cut prior to
failure for all of the working examples. The thermal stability of
the copper-infiltrated PCD tables of examples 4 and 5 was evaluated
by measuring the distance cut in the same workpiece used to test
comparative examples 1-3 and using the same test parameters,
without using coolant, in a vertical turret lathe test. The
copper-infiltrated PCD tables of the PDCs of examples 4 and 5 were
able to cut a distance about 13706 and 13758 linear feet,
respectively, in the workpiece, which was greater than the distance
that the un-leached and leached PDCs of comparative examples 1-3
were able to cut. The thermal stability tests were stopped before
the copper-infiltrated PCD tables of the PDCs of examples 4 and 5
failed.
[0101] Scanning electron microscopy was performed on a PDC
fabricated in accordance with examples 4 and 5, while the PDC was
heated to a temperature of about 1338.degree. C. FIG. 12 is a
scanning electron photomicrograph showing the copper infiltrant
(light regions) being extruded out of an upper surface of the
copper-infiltrated PCD table and from between the diamond grains
(dark regions) of the copper-infiltrated PCD table during heating
at a temperature of about 1338.degree. C. No evidence of any
cracking of the copper-infiltrated PCD table was observed during
the scanning electron microscopy.
EXAMPLES 6 AND 7
[0102] Two PDCs were fabricated as performed in examples 4 and 5.
The nominal thickness of the PCD tables of the PDCs were about
2.286 mm and an about 45 degree, 0.3048-mm nominal chamfer was
machined in the PCD tables. Then, the PCD tables were acid leached
after machining to remove at least some of the copper from the
copper-infiltrated PCD tables.
[0103] The thermal stability of the leached copper-infiltrated PCD
tables of examples 6 and 7 was evaluated by measuring the distance
cut in the same workpiece used to test comparative examples 1-5 and
using the same test parameters, without using coolant, in a
vertical turret lathe test. As shown in FIG. 11, the leached
copper-infiltrated PCD tables of the PDCs of examples 6 and 7 were
able to cut a distance about 13731 and 13690 linear feet,
respectively, in the workpiece, which was greater than the distance
that the un-leached and leached PDCs of comparative examples 1-3
were able to cut. The thermal stability tests were stopped before
the leached copper-infiltrated PCD tables of the PDCs of examples 6
and 7 failed.
EXAMPLES 8 THROUGH 10
[0104] Three PDCs were fabricated as performed in examples 4 and 5
except a layer of tin was employed instead of a layer of copper to
infiltrate an upper region of the at least partially leached PCD
tables. The nominal thickness of the PCD tables of the PDCs were
about 2.286 mm and an about 45 degree, 0.3048-mm nominal chamfer
was machined in the PCD tables.
[0105] The thermal stability of the copper-infiltrated PCD tables
of examples 8-10 was evaluated by measuring the distance cut in the
same workpiece used to test comparative examples 1-7 and using the
same test parameters, without using coolant, in a vertical turret
lathe test. As shown in FIG. 11, the tin-infiltrated PCD tables of
the PDCs of examples 8-10 were able to cut a distance of about
17662, 22154, and 14048 linear feet, respectively, in the workpiece
prior to failure, which was greater than the distance that the
un-leached and leached PDCs of comparative examples 1-3 were able
to cut.
EXAMPLES 11 THROUGH 13
[0106] Three PDCs were fabricated as performed in examples 4 and 5
except a layer of aluminum was employed instead of a layer of
copper to infiltrate an upper region of the at least partially
leached PCD tables. The nominal thickness of the PCD tables of the
PDCs were about 2.286 mm and an about 45 degree, 0.3048-mm nominal
chamfer was machined in the PCD tables.
[0107] The thermal stability of the aluminum-infiltrated PCD tables
of examples 11-13 was evaluated by measuring the distance cut in
the same workpiece used to test comparative examples 1-10 and using
the same test parameters, without using coolant, in a vertical
turret lathe test. As shown in FIG. 11, the aluminum-infiltrated
PCD tables of the PDCs of examples 11-13 were able to cut a
distance of about 8850, 11372, and 21628 linear feet, respectively,
in the workpiece prior to failure, which was greater than the
distance that the un-leached and leached PDCs of comparative
examples 1-3 were able to cut.
[0108] While various aspects and embodiments have been disclosed
herein, other aspects and embodiments are contemplated. The various
aspects and embodiments disclosed herein are for purposes of
illustration and are not intended to be limiting. Additionally, the
words "including," "having," and variants thereof (e.g., "includes"
and "has") as used herein, including the claims, shall be open
ended and have the same meaning as the word "comprising" and
variants thereof (e.g., "comprise" and "comprises").
* * * * *