U.S. patent application number 13/286355 was filed with the patent office on 2013-05-02 for earth boring cutting inserts and earth boring bits including the same.
This patent application is currently assigned to TDY Industries, Inc.. The applicant listed for this patent is Gabriel B. Collins, Oladapo O. Eso, John L. Johnson, Prakash K. Mirchandani, James J. Oakes. Invention is credited to Gabriel B. Collins, Oladapo O. Eso, John L. Johnson, Prakash K. Mirchandani, James J. Oakes.
Application Number | 20130105231 13/286355 |
Document ID | / |
Family ID | 47226397 |
Filed Date | 2013-05-02 |
United States Patent
Application |
20130105231 |
Kind Code |
A1 |
Oakes; James J. ; et
al. |
May 2, 2013 |
EARTH BORING CUTTING INSERTS AND EARTH BORING BITS INCLUDING THE
SAME
Abstract
An earth boring cutting insert including a cemented carbide
comprising metal carbide grains dispersed in a metallic binder
including at least one of platinum, palladium, rhenium, rhodium,
and ruthenium. Also disclosed is an earth boring bit such as, for
example, a rotary-cone earth boring bit or a percussion bit,
including at least one earth boring cutting insert comprising a
cemented carbide including a metallic binder comprising at least
one of platinum, palladium, rhenium, rhodium, and ruthenium
Inventors: |
Oakes; James J.; (Madison,
AL) ; Mirchandani; Prakash K.; (Houston, TX) ;
Collins; Gabriel B.; (Huntsville, AL) ; Eso; Oladapo
O.; (Harvest, AL) ; Johnson; John L.; (Toney,
AL) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Oakes; James J.
Mirchandani; Prakash K.
Collins; Gabriel B.
Eso; Oladapo O.
Johnson; John L. |
Madison
Houston
Huntsville
Harvest
Toney |
AL
TX
AL
AL
AL |
US
US
US
US
US |
|
|
Assignee: |
TDY Industries, Inc.
Pittsburgh
PA
|
Family ID: |
47226397 |
Appl. No.: |
13/286355 |
Filed: |
November 1, 2011 |
Current U.S.
Class: |
175/428 |
Current CPC
Class: |
E21B 10/5673 20130101;
B22F 2998/00 20130101; B22F 2005/001 20130101; C22C 29/067
20130101; B22F 2998/00 20130101; C22C 29/08 20130101 |
Class at
Publication: |
175/428 |
International
Class: |
E21B 10/36 20060101
E21B010/36 |
Claims
1. An earth boring cutting insert including: a cemented carbide
comprising a metallic binder including greater than an impurities
concentration of one or more elements selected from the group
consisting of platinum, palladium, rhenium, rhodium, and
ruthenium.
2. The earth boring cutting insert of claim 1, wherein the cemented
carbide comprises: a dispersed phase including hard grains
including metal carbide comprising at least one transition metal
selected from titanium, vanadium, chromium, zirconium, niobium,
molybdenum, hafnium, tantalum, and tungsten; and a continuous phase
of a metallic binder comprising at least one of cobalt, a cobalt
alloy, nickel, a nickel alloy, iron, and an iron alloy, and at
least one element selected from the group consisting of platinum,
palladium, rhenium, rhodium, and ruthenium, wherein the combined
concentration of platinum, palladium, rhenium, rhodium, and
ruthenium in the metallic binder is 0.1 to 10 weight percent, based
on the total weight of the cemented carbide.
3. The earth boring cutting insert of claim 2, wherein the metallic
binder comprises a combined concentration of platinum, palladium,
rhenium, rhodium, and ruthenium in the metallic binder that is 0.3
to 7 weight percent, based on the total weight of the cemented
carbide.
4. The earth boring cutting insert of claim 2, wherein the metallic
binder comprises a combined concentration of platinum, palladium,
rhenium, rhodium, and ruthenium in the metallic binder that is 0.5
to 5 weight percent, based on the total weight of the cemented
carbide.
5. The earth boring cutting insert of claim 2, wherein the cemented
carbide comprises 2 to 40 weight percent of the metallic binder and
60 to 98 weight percent of the dispersed phase.
6. The earth boring cutting insert of claim 2, wherein the hard
grains of the dispersed phase comprise at least one of titanium
carbide, vanadium carbide, chromium carbide, zirconium carbide,
niobium carbide, molybdenum carbide, hafnium carbide, tantalum
carbide, and tungsten carbide.
7. The earth boring cutting insert of claim 2, wherein the hard
grains of the dispersed phase comprise tungsten carbide.
8. The earth boring cutting insert of claim 2, wherein the metallic
binder comprises cobalt and ruthenium.
9. The earth boring cutting insert of claim 2, wherein the hard
grains of the dispersed phase comprise tungsten carbide, and the
metallic binder comprises cobalt and ruthenium.
10. The earth boring cutting insert of claim 2, wherein the hard
grains of the dispersed phase consist essentially of tungsten
carbide, and the metallic binder comprises cobalt and
ruthenium.
11. The earth boring cutting insert of claim 1, wherein the cutting
insert is adapted for use with at least one of a rotary-cone earth
boring bit and a percussion bit.
12. The earth boring cutting insert of claim 2, wherein the cutting
insert is adapted for use with at least one of a rotary-cone earth
boring bit and a percussion bit.
13. The earth boring cutting insert of claim 1, wherein the cutting
insert comprises a working portion and a body portion.
14. The earth boring cutting insert of claim 13, wherein the
working portion includes a shape selected from an ovoid shape, a
ballistic shape, a chisel shape, a multi-dome shape, and a conical
shape.
15. The earth boring cutting insert of claim 2, wherein the cutting
insert comprises a working portion and a body portion.
16. The earth boring cutting insert of claim 15, wherein the
working portion comprises a shape selected from an ovoid shape, a
ballistic shape, a chisel shape, a multi-dome shape, and a conical
shape.
17. The earth boring cutting insert of claim 1, wherein the cutting
insert comprises: a first region comprising a first cemented
carbide including a dispersed phase including hard grains of metal
carbide in a metallic binder, the metallic binder of the first
cemented carbide including at least one of platinum, palladium,
rhenium, rhodium, and ruthenium, wherein a combined concentration
of platinum, palladium, rhenium, rhodium, and ruthenium in the
metallic binder is 0.1 to 10 weight percent, based on the weight of
the first cemented carbide; and a second region comprising a second
cemented carbide including a dispersed phase including hard grains
of metal carbide in a metallic binder, wherein the metallic binder
of the second cemented carbide includes a combined concentration of
platinum, palladium, rhenium, rhodium, and ruthenium that is less
than the combined concentration of platinum, palladium, rhenium,
rhodium, and ruthenium in the metallic binder of the first cemented
carbide.
18. The earth boring cutting insert of claim 17, wherein the
metallic binder of the first cemented carbide comprises a combined
concentration of platinum, palladium, rhenium, rhodium, and
ruthenium in the metallic binder that is 0.3 to 7 weight percent,
based on the total weight of the cemented carbide.
19. The earth boring cutting insert of claim 17, wherein the
metallic binder of the first cemented carbide comprises a combined
concentration of platinum, palladium, rhenium, rhodium, and
ruthenium in the metallic binder that is 0.5 to 5 weight percent,
based on the total weight of the cemented carbide.
20. The earth boring cutting insert of claim 17, wherein the
metallic binder of the first cemented carbide comprises 0.1 to 10
weight percent ruthenium, based on the total weight of the first
cemented carbide.
21. The earth boring cutting insert of claim 17, wherein the
metallic binder of the second cemented carbide including no greater
than an impurities concentration of ruthenium.
22. The earth boring cutting insert of claim 17, wherein the
metallic binder of the second cemented carbide does not include
ruthenium.
23. The earth boring cutting insert of claim 17, wherein the first
cemented carbide and the second cemented carbide each individually
comprise: a dispersed phase including hard grains of metal carbide
comprising at least one transition metal selected from titanium,
vanadium, chromium, zirconium, niobium, molybdenum, hafnium,
tantalum, and tungsten; and a continuous phase of a metallic binder
comprising at least one of cobalt, a cobalt alloy, nickel, a nickel
alloy, iron, and an iron alloy.
24. The earth boring cutting insert of claim 17, wherein the first
region includes a working portion of the cutting insert.
25. The earth boring cutting insert of claim 24, wherein the
working portion comprises a shape selected from an ovoid shape, a
ballistic shape, a chisel shape, a multi-dome shape, and a conical
shape.
26. The earth boring cutting insert of claim 17, wherein: the
dispersed phase of the first cemented carbide comprises tungsten
carbide, and the metallic binder of the first cemented carbide
comprises cobalt; and the dispersed phase of the second cemented
carbide comprises tungsten carbide, and the metallic binder of the
second cemented carbide comprises cobalt.
27. The earth boring cutting insert of claim 17, wherein the
cutting insert is adapted for use with at least one of a
rotary-cone earth boring bit and a percussion bit.
28. An earth boring cutting insert comprising: a working portion
comprising a first cemented carbide including a dispersed phase
including hard grains of metal carbide comprising at least one
transition metal selected from titanium, vanadium, chromium,
zirconium, niobium, molybdenum, hafnium, tantalum, and tungsten,
and a continuous phase of a metallic binder comprising at least one
of cobalt, a cobalt alloy, nickel, a nickel alloy, iron, and an
iron alloy, and at least one element selected from the group
consisting of platinum, palladium, rhenium, rhodium, and ruthenium,
wherein the combined concentration of platinum, palladium, rhenium,
rhodium, and ruthenium in the metallic binder is 0.1 to 10 weight
percent, based on the total weight of the first cemented carbide;
and a body portion comprising a second cemented carbide including a
dispersed phase including hard grains of metal carbide comprising
at least one transition metal selected from titanium, chromium,
vanadium, zirconium, hafnium, tantalum, molybdenum, niobium, and
tungsten, and a continuous phase of a metallic binder comprising at
least one of cobalt, a cobalt alloy, nickel, a nickel alloy, iron,
and an iron alloy, and a combined concentration of platinum,
palladium, rhenium, rhodium, and ruthenium in the metallic binder
that is less than the combined concentration of platinum,
palladium, rhenium, rhodium, and ruthenium in the metallic binder
of the first cemented carbide.
29. The earth boring cutting insert of claim 28, wherein the
metallic binder of the first cemented carbide comprises a combined
concentration of platinum, palladium, rhenium, rhodium, and
ruthenium that is 0.3 to 7 weight percent, based on the total
weight of the first cemented carbide.
30. The earth boring cutting insert of claim 28, wherein the
metallic binder of the first cemented carbide comprises a combined
concentration of platinum, palladium, rhenium, rhodium, and
ruthenium that is 0.5 to 5 weight percent, based on the total
weight of the first cemented carbide.
31. The earth boring cutting insert of claim 28, wherein the
dispersed phase of the first cemented carbide comprises tungsten
carbide; and the metallic binder of the first cemented carbide
comprises cobalt.
32. The earth boring cutting insert of claim 31, wherein the
dispersed phase of the second cemented carbide comprises tungsten
carbide; and the metallic binder of the second cemented carbide
comprises cobalt.
33. An earth boring bit comprising: a bit body; and at least one
earth boring cutting insert comprising a metallic binder including
at least one element selected from the group consisting of
platinum, palladium, rhenium, rhodium, and ruthenium, wherein the
combined concentration of platinum, palladium, rhenium, rhodium,
and ruthenium in the metallic binder is 0.1 to 10 weight percent,
based on the total weight of the cemented carbide.
34. The earth boring bit of claim 33, wherein the cemented carbide
comprises: a dispersed phase including hard grains of metal carbide
comprising at least one transition metal selected from titanium,
vanadium, chromium, zirconium, niobium, molybdenum, hafnium,
tantalum, and tungsten; and a continuous phase of a metallic binder
comprising 0.1 to 10 weight percent ruthenium, based on the total
weight of the cemented carbide, and at least one of cobalt, a
cobalt alloy, nickel, a nickel alloy, iron, and an iron alloy.
35. The earth boring bit of claim 34, wherein the metallic binder
comprises a combined concentration of platinum, palladium, rhenium,
rhodium, and ruthenium that is 0.3 to 7 weight percent, based on
the total weight of the cemented carbide.
36. The earth boring bit of claim 34, wherein the metallic binder
comprises a combined concentration of platinum, palladium, rhenium,
rhodium, and ruthenium that is 0.5 to 5 weight percent, based on
the total weight of the cemented carbide.
37. The earth boring bit of claim 34, wherein the cemented carbide
comprises 2 to 40 weight percent of the metallic binder and 60 to
98 weight percent of the dispersed phase.
38. The earth boring bit of claim 34, wherein the hard grains of
the dispersed phase comprise at least one of titanium carbide,
vanadium carbide, chromium carbide, zirconium carbide, niobium
carbide, molybdenum carbide, hafnium carbide, tantalum carbide, and
tungsten carbide.
39. The earth boring bit of claim 34, wherein the hard grains of
the dispersed phase comprise tungsten carbide.
40. The earth boring bit of claim 34, wherein the metallic binder
comprises cobalt and ruthenium.
41. The earth boring bit of claim 33, wherein the earth boring bit
is one of a rotary-cone earth boring bit and a percussion bit.
42. The earth boring bit of claim 34, wherein the earth boring bit
is one of a rotary-cone earth boring bit and a percussion bit.
43. The earth boring bit of claim 33, wherein the at least one
earth boring cutting insert comprises: a first region comprising a
first cemented carbide including metal carbide grains dispersed in
a metallic binder, the metallic binder of the first cemented
carbide including at least one element selected from the group
consisting of platinum, palladium, rhenium, rhodium, and ruthenium,
wherein the combined concentration of platinum, palladium, rhenium,
rhodium, and ruthenium in the metallic binder is 0.1 to 10 weight
percent, based on the total weight of the first cemented carbide;
and a second region comprising a second cemented carbide including
metal carbide grains dispersed in a metallic binder, wherein the
metallic binder of the second cemented carbide includes a combined
concentration of platinum, palladium, rhenium, rhodium, and
ruthenium in the metallic binder that is less than the combined
concentration of platinum, palladium, rhenium, rhodium, and
ruthenium in the metallic binder of the first cemented carbide.
44. The earth boring bit of claim 43, wherein the metallic binder
of the first cemented carbide comprises 0.1 to 10 weight percent
ruthenium, based on the total weight of the first cemented
carbide.
45. The earth boring bit of claim 43, wherein the metallic binder
of the first cemented carbide comprises a combined concentration of
platinum, palladium, rhenium, rhodium, and ruthenium in the
metallic binder that is 0.3 to 7 weight percent, based on the total
weight of the first cemented carbide.
46. The earth boring bit of claim 43, wherein the metallic binder
of the first cemented carbide comprises a combined concentration of
platinum, palladium, rhenium, rhodium, and ruthenium in the
metallic binder that is 0.5 to 5 weight percent, based on the total
weight of the first cemented carbide.
47. The earth boring bit of claim 43, wherein the metallic binder
of the second cemented carbide does not include ruthenium.
48. The earth boring bit of claim 43, wherein: the first cemented
carbide comprises tungsten carbide grains, and the metallic binder
of the first cemented carbide comprises cobalt; and the second
cemented carbide comprises tungsten carbide grains, and the
metallic binder of the second cemented carbide comprises
cobalt.
49. The earth boring bit of claim 43, wherein the earth boring bit
is one of a rotary-cone earth boring bit and a percussion bit.
50. An earth boring bit including at least one earth boring cutting
insert comprising: a working portion comprising a first cemented
carbide including a dispersed phase including hard grains of metal
carbide comprising at least one transition metal selected from
titanium, vanadium, chromium, zirconium, niobium, molybdenum,
hafnium, tantalum, and tungsten, and a continuous phase of a
metallic binder comprising at least one of cobalt, a cobalt alloy,
nickel, a nickel alloy, iron, and an iron alloy, and at least one
of platinum, palladium, rhenium, rhodium, and ruthenium, wherein
the combined concentration of platinum, palladium, rhenium,
rhodium, and ruthenium in the metallic binder is 0.1 to 10 weight
percent, based on the total weight of the first cemented carbide;
and a body portion comprising a second cemented carbide including a
dispersed phase including hard grains of metal carbide comprising
at least one transition metal selected from titanium, chromium,
vanadium, zirconium, hafnium, tantalum, molybdenum, niobium, and
tungsten, and a continuous phase of a metallic binder comprising at
least one of cobalt, a cobalt alloy, nickel, a nickel alloy, iron,
and an iron alloy, and a combined concentration of platinum,
palladium, rhenium, rhodium, and ruthenium that is less than the
combined concentration of platinum, palladium, rhenium, rhodium,
and ruthenium in the metallic binder of the first cemented
carbide.
51. The earth boring bit of claim 50, wherein the metallic binder
of the first cemented carbide comprises 0.1 to 10 weight percent
ruthenium, based on the total weight of the first cemented
carbide.
52. The earth boring bit of claim 50, wherein the metallic binder
of the first cemented carbide comprises a combined concentration of
platinum, palladium, rhenium, rhodium, and ruthenium in the
metallic binder that is 0.3 to 7 weight percent, based on the total
weight of the first cemented carbide.
53. The earth boring bit of claim 50, wherein the metallic binder
of the first cemented carbide comprises a combined concentration of
platinum, palladium, rhenium, rhodium, and ruthenium in the
metallic binder that is 0.5 to 5 weight percent, based on the total
weight of the first cemented carbide
54. The earth boring bit of claim 50, wherein the dispersed phase
of the first cemented carbide comprises tungsten carbide; and the
metallic binder of the first cemented carbide comprises cobalt.
Description
FIELD OF TECHNOLOGY
[0001] This disclosure relates to improvements to earth boring
cutting inserts including cemented carbide for use with earth
boring bits such as, for example, rotary-cone earth boring bits and
percussion bits (such as, for example, hammer bits). This
disclosure also relates to earth boring bits including an earth
boring bit body and at least one earth boring cutting insert
according to the present disclosure mounted on the bit body.
BACKGROUND OF THE INVENTION
[0002] Earth boring (or drilling) bits are commonly employed for
oil and natural gas exploration, mining, and excavation. Such earth
boring bits may include rotatable or fixed cutting elements. For
example, FIG. 1 illustrates a typical rotary-cone earth boring bit
10 including a bit body comprising rotatable cutting elements 11,
commonly referred to as "rotary cones". Cutting inserts 12, which
may be made from cemented carbide, are mounted in cutting inserts
pockets located on outer surfaces of each of the rotatable cutting
elements 11. Several cutting inserts 12 may be mounted on the
rotatable cutting elements 11 in various predetermined positions to
optimize the cutting action of the earth boring bit 10.
[0003] The service life of an earth boring bit is typically a
function of the wear properties of the bit's cutting inserts. One
technique to increase earth boring bit service life is to employ
earth boring cutting inserts made of materials having improved
combinations of strength, toughness, and wear resistance. Many
conventional earth boring bits utilize cutting elements made from
cemented carbide, which is a cemented hard particle material. The
choice of cemented carbide for such applications is predicated on
the fact that these materials offer very attractive combinations of
strength, fracture toughness, and wear resistance, properties that
are extremely important to the efficient and economical functioning
of an earth boring bit. Cemented carbides are composites comprising
a discontinuous dispersed phase that typically includes hard grains
comprising carbides of one or more of the transition metals
belonging to groups IVB, VB, and VIB of the periodic table. These
transition metals include, for example, titanium (Ti), vanadium
(V), chromium (Cr), zirconium (Zr), niobium, (Nb), molybdenum (Mo),
hafnium (Hf), tantalum (Ta), and tungsten (W). The hard grains of
the dispersed phase are bound or "cemented" together by a
continuous phase of a metallic binder that typically includes on or
more of cobalt, a cobalt alloy, nickel, a nickel alloy, iron, and
an iron alloy. Among the different possible hard grain-metallic
binder combinations, cemented carbides based on tungsten carbide
(WC) as the dispersed phase hard grains and cobalt (Co) or nickel
(Ni) as the metallic binder (i.e., WC--Co based cemented carbides
and WC--Ni based cemented carbides, respectively) are commonly
employed in earth boring applications.
[0004] Mechanical properties of cemented carbides important to
earth boring applications largely depend on two microstructural
parameters, namely, (i) the average hard grain size and (ii) the
weight or volume fraction of the hard grains and/or the metallic
binder in the cemented carbide. In general, the hardness and wear
resistance of a cemented carbide increases as the dispersed phase
hard grain size decreases and/or the metallic binder content
decreases. On the other hand, fracture toughness of a cemented
carbide increases as the dispersed phase hard grain size increases
and/or as the metallic binder content increases. Thus, there is a
trade-off between wear resistance and fracture toughness when
selecting a cemented carbide grade for any application. As wear
resistance increases, fracture toughness typically decreases, and
vice versa.
[0005] FIGS. 2A-2E illustrate a selection of different shapes and
designs of conventional cemented carbide cutting inserts used with
rotary-cone earth boring bits. Earth boring cutting inserts may be
characterized by the shape of the insert's domed portion. Available
shapes include, for example, ovoid shapes (FIG. 2A), ballistic
shapes (FIG. 2B), chisel shapes (FIG. 2C), multidome shapes (FIG.
2D), and conical shapes (FIG. 2E). The choice of the shape and
cemented carbide composition (i.e., grade) employed is influenced
by, for example, the type of rock to be drilled or otherwise
excavated. Regardless of shape or size, earth boring cutting
inserts typically include a working portion and a body portion. For
example, the earth boring cutting insert 30 shown in FIG. 2A
includes dome-shaped working portion 32 and body portion 34. Also,
for example, the earth boring cutting insert 40 shown in FIG. 2B
includes ballistic-shaped cutting portion 42 and body portion 44.
The cutting action is wholly or principally performed by the
working portion, while the body portion provides support for the
working portion. In general, most or all of the body portion is
embedded within the bit body, and the body portion is typically
mounted on the bit body by press fitting or is otherwise secured in
a cutting insert pocket provided on the bit body.
[0006] As previously stated, the drilling/cutting action may be at
least primarily provided by a working portion of an earth boring
cutting inserts. The first region of the working portion of an
earth boring cutting insert that begins wearing away is the top
half and, in particular, the extreme tip, of the working portion.
As the top of the working portion of an earth boring cutting insert
begins to flatten out, the efficiency of cutting decreases
dramatically given that the rock and earth is being removed more by
a rubbing action, as opposed to a more efficient cutting action. As
the rubbing action continues, considerable heat may be generated by
the increase in friction between the material and the cutting
insert, thereby resulting in increased heating of portions of the
cutting insert. If the temperature of any portion of cemented
carbide earth boring cutting insert exceeds a threshold valve,
thermal cracks may be initiated at the interface of the hard grains
and the metallic binder. Thermal cycling of the article exacerbates
propagation of thermal cracks. Crack propagation may result in
fracturing of a cutting insert, which may necessitate replacement
of the cutting inert or the entire bit. Retrieving a drill string
from a drill hole, for example, to access and repair or place an
earth boring bit including fractured cutting inserts significantly
slows and adds substantial expense to the drilling process.
[0007] Accordingly, there is a need for improved cemented carbide
cutting inserts useful for earth boring bits. The improved cutting
inserts preferably should have an increased level of wear
resistance without loss of fracture toughness. In this way, cutting
efficiency may be improved and the service life of the cutting
inserts, and the earth boring bit as a whole, may be extended.
SUMMARY OF THE PRESENT INVENTION
[0008] The present disclosure provides an improved earth boring
cutting insert including a cemented carbide comprising greater than
impurities concentrations of one or more elements selected from the
group consisting of platinum, palladium, rhenium, rhodium, and
ruthenium. The present disclosure also is directed to an earth
boring bit such as, for example, a rotary-cone earth boring bit or
a percussion bit, including at least one earth boring cutting
insert including a cemented carbide comprising greater than
impurities concentrations of one or more elements selected from the
group consisting of platinum, palladium, rhenium, rhodium, and
ruthenium.
[0009] According to one non-limiting aspect of the present
disclosure, an earth boring cutting insert includes a cemented
carbide comprising a metallic binder that includes at least one
element selected from the group consisting of platinum, palladium,
rhenium, rhodium, and ruthenium. In certain non-limiting
embodiments, the cemented carbide includes a dispersed phase
including hard grains of metal carbide comprising at least one
transition metal selected from titanium, vanadium, chromium,
zirconium, niobium, molybdenum, hafnium, tantalum, and tungsten;
and a continuous phase of a metallic binder including at least one
of cobalt, a cobalt alloy, nickel, a nickel alloy, iron, and an
iron alloy, and at least one element selected from the group
consisting of platinum, palladium, rhenium, rhodium, and ruthenium,
wherein the combined concentration of platinum, palladium, rhenium,
rhodium, and ruthenium in the metallic binder is 0.1 to 10 weight
percent, based on the total weight of the cemented carbide.
[0010] According to another non-limiting aspect of the present
disclosure, an earth boring cutting insert includes two or more
regions. A first region comprises a first cemented carbide
including hard grains of metal carbide dispersed in a metallic
binder, wherein the metallic binder includes at least one element
selected from the group consisting of platinum, palladium, rhenium,
rhodium, and ruthenium, wherein the combined concentration of
platinum, palladium, rhenium, rhodium, and ruthenium in the
metallic binder is 0.1 to 10 weight percent, based on the total
weight of the cemented carbide. A second region comprises a second
cemented carbide including hard grains of metal carbide comprising
at least one transition metal selected from titanium, vanadium,
chromium, zirconium, niobium, molybdenum, hafnium, tantalum, and
tungsten; and a continuous phase of a metallic binder including a
combined concentration of platinum, palladium, rhenium, rhodium,
and ruthenium that is less than the combined concentration of
platinum, palladium, rhenium, rhodium, and ruthenium in the
metallic binder of the first cemented carbide.
[0011] According to yet another non-limiting embodiment of the
present disclosure, an earth boring cutting insert includes a
working portion comprising a first cemented carbide, and a body
portion including a second cemented carbide. The first cemented
carbide includes a dispersed phase including hard grains of metal
carbide comprising at least one transition metal selected from
titanium, vanadium, chromium, zirconium, niobium, molybdenum,
hafnium, tantalum, and tungsten. The first cemented carbide also
includes a continuous phase of a metallic binder comprising at
least one of cobalt, a cobalt alloy, nickel, a nickel alloy, iron,
and an iron alloy, and at least one element selected from the group
consisting of platinum, palladium, rhenium, rhodium, and ruthenium,
wherein the combined concentration of platinum, palladium, rhenium,
rhodium, and ruthenium in the metallic binder is 0.1 to 10 weight
percent, based on the total weight of the cemented carbide. The
second cemented carbide includes a dispersed phase of hard grains
of metal carbide comprising at least one transition metal selected
from titanium, vanadium, chromium, zirconium, niobium, molybdenum,
hafnium, tantalum, and tungsten. The second cemented carbide also
includes a continuous phase of a metallic binder including a
combined concentration of platinum, palladium, rhenium, rhodium,
and ruthenium that is less than the combined concentration of
platinum, palladium, rhenium, rhodium, and ruthenium in the
metallic binder of the first cemented carbide.
[0012] According to a further aspect of the present disclosure, an
earth boring bit includes a bit body and at least one earth boring
cutting insert. The at least one earth boring cutting insert
comprises a metallic binder including at least one element selected
from the group consisting of platinum, palladium, rhenium, rhodium,
and ruthenium, wherein the combined concentration of platinum,
palladium, rhenium, rhodium, and ruthenium in the metallic binder
is 0.1 to 10 weight percent, based on the total weight of the
cemented carbide. In certain non-limiting embodiments of the earth
boring bit, the cemented carbide includes a dispersed phase
including hard grains of metal carbide comprising at least one
transition metal selected from titanium, vanadium, chromium,
zirconium, niobium, molybdenum, hafnium, tantalum, and tungsten;
and a continuous phase of a metallic binder comprising at least one
of cobalt, a cobalt alloy, nickel, a nickel alloy, iron, and an
iron alloy, and at least one element selected from the group
consisting of platinum, palladium, rhenium, rhodium, and ruthenium,
wherein the combined concentration of platinum, palladium, rhenium,
rhodium, and ruthenium in the metallic binder is 0.1 to 10 weight
percent, based on the total weight of the cemented carbide. The
earth boring bit according to the present disclosure may be, for
example, a rotary-cone earth boring bit or a percussion bit (such
as, for example, a hammer bit).
[0013] According to yet a further non-limiting aspect of the
present disclosure, an earth boring bit includes a bit body and an
earth boring cutting insert comprising two or more regions. A first
region of the earth boring cutting insert comprises a first
cemented carbide including a metallic binder, wherein the metallic
binder includes at least one element selected from the group
consisting of platinum, palladium, rhenium, rhodium, and ruthenium,
wherein the combined concentration of platinum, palladium, rhenium,
rhodium, and ruthenium in the metallic binder is 0.1 to 10 weight
percent, based on the total weight of the cemented carbide. A
second region of the at least one earth boring cutting insert
includes a second cemented carbide including a metallic binder that
includes a combined concentration of platinum, palladium, rhenium,
rhodium, and ruthenium that is less than the combined concentration
of platinum, palladium, rhenium, rhodium, and ruthenium in the
metallic binder of the first cemented carbide. The earth boring bit
according to the present disclosure may be, for example, a
rotary-cone earth boring bit or a percussion bit (such as, for
example, a hammer bit).
[0014] According to an additional aspect of the present disclosure,
an earth boring bit includes a bit body and at least one earth
boring cutting insert mounted on the bit body. The at least one
earth boring cutting insert includes a working portion comprising a
first cemented carbide, and a body portion comprising a second
cemented carbide. The first cemented carbide includes a dispersed
phase of hard grains of metal carbide comprising at least one
transition metal selected from titanium, vanadium, chromium,
zirconium, niobium, molybdenum, hafnium, tantalum, and tungsten.
The first cemented carbide also includes a continuous phase of a
metallic binder comprising at least one of cobalt, a cobalt alloy,
nickel, a nickel alloy, iron, and an iron alloy, and at least one
element selected from the group consisting of platinum, palladium,
rhenium, rhodium, and ruthenium, wherein the combined concentration
of platinum, palladium, rhenium, rhodium, and ruthenium in the
metallic binder is 0.1 to 10 weight percent, based on the total
weight of the cemented carbide. The second cemented carbide
includes a dispersed phase of hard grains including carbides of at
least one transition metal selected from titanium, chromium,
vanadium, zirconium, hafnium, tantalum, molybdenum, niobium, and
tungsten. The second cemented carbide also includes a continuous
phase of a metallic binder that includes a combined concentration
of platinum, palladium, rhenium, rhodium, and ruthenium that is
less than the combined concentration of platinum, palladium,
rhenium, rhodium, and ruthenium in the metallic binder of the first
cemented carbide. The earth boring bit according to the present
disclosure may be, for example, a rotary-cone earth boring bit or a
percussion bit (such as, for example, a hammer bit).
[0015] The reader will appreciate the foregoing details and
advantages of the present invention, as well as others, upon
consideration of the following detailed description of certain
non-limiting embodiments of the invention. The reader also may
comprehend such additional details and advantages of the present
invention upon making and/or using embodiments within the present
invention.
BRIEF DESCRIPTION OF THE FIGURES
[0016] The features and advantages of the present invention may be
better understood by reference to the accompanying figures in
which:
[0017] FIG. 1 illustrates a typical rotary-cone earth boring bit
comprising a bit body, roller cones, and cutting inserts;
[0018] FIGS. 2A-2E illustrate different shapes and sizes of cutting
inserts typically employed in earth boring bits such as ovoid (FIG.
2A), ballistic (FIG. 2B), chisel (FIG. 2C), multidome (FIG. 2D),
and conical (FIG. 2E);
[0019] FIG. 3 shows the typical microstructure of a cemented hard
particle material having a continuous phase of a metallic binder,
and a dispersed phase comprising hard grains;
[0020] FIG. 4 is a graph showing the relationship between wear
resistance and fracture toughness for cemented carbide grades
listed in Table 1;
[0021] FIG. 5 is a graph showing the relationship between wear
resistance and fracture toughness for experimental cemented carbide
grades listed in Table 2;
[0022] FIGS. 6A-D are micrographs showing the microstructure of
certain embodiments of cemented carbides discussed herein; and
[0023] FIGS. 7(a)-(e) are photographs illustrating various aspects
of a non-limiting embodiment of an earth boring cutting insert
according to the present disclosure including first and second
cemented carbides
DESCRIPTION OF NON-LIMITING EMBODIMENTS OF THE INVENTION
[0024] Various embodiments are described and illustrated in this
specification to provide an overall understanding of the structure,
function, properties, and use of the disclosed earth boring cutting
inserts and earth boring bits. It is understood that the various
embodiments described and illustrated in this specification are
non-limiting and non-exhaustive. Thus, the invention is not limited
by the description of the various non-limiting and non-exhaustive
embodiments disclosed in this specification. The features and
characteristics described in connection with various embodiments
may be combined with the features and characteristics of other
embodiments. Such modifications and variations are intended to be
included within the scope of this specification. As such, the
claims may be amended to recite any features or characteristics
expressly or inherently described in, or otherwise expressly or
inherently supported by, this specification. Further, Applicants
reserve the right to amend the claims to affirmatively disclaim
features or characteristics that are present in the prior art
regardless of whether such features are explicitly described
herein. Therefore, any such amendments comply with the requirements
of 35 U.S.C. .sctn.112, first paragraph, and 35 U.S.C.
.sctn.132(a). The various embodiments disclosed and described in
this specification can comprise, consist of, or consist essentially
of the features and characteristics as variously described
herein.
[0025] Any patent, publication, or other disclosure material
identified herein is incorporated by reference into this
specification in its entirety unless otherwise indicated, but only
to the extent that the incorporated material does not conflict with
existing definitions, statements, or other disclosure material
expressly set forth in this specification. As such, and to the
extent necessary, the express disclosure as set forth in this
specification supersedes any conflicting material incorporated by
reference herein. Any material, or portion thereof, that is said to
be incorporated by reference into this specification, but which
conflicts with existing definitions, statements, or other
disclosure material set forth herein, is only incorporated to the
extent that no conflict arises between that incorporated material
and the existing disclosure material. Applicants reserve the right
to amend this specification to expressly recite any subject matter,
or portion thereof, incorporated by reference herein.
[0026] The grammatical articles "one", "a", "an", and "the", as
used in this specification, are intended to include "at least one"
or "one or more", unless otherwise indicated. Thus, the articles
are used in this specification to refer to one or more than one
(i.e., to "at least one") of the grammatical objects of the
article. By way of example, "a component" means one or more
components, and thus, possibly, more than one component is
contemplated and may be employed or used in an implementation of
the described embodiments. Further, the use of a singular noun
includes the plural, and the use of a plural noun includes the
singular, unless the context of the usage requires otherwise.
[0027] Various embodiments disclosed and described in this
specification are directed to improved cutting inserts adapted for
use with earth boring bits. For example, certain embodiments of the
cutting inserts according to the present disclosure may be used
with percussion bits (which include, for example, hammer bits) or
with rotary-cone earth boring bits for oil and natural gas
exploration and extraction, mining, excavation, and related
drilling and cutting operations. According to one aspect of the
present disclosure, earth boring cutting inserts described herein
comprise, consist essentially of, or consist of a cemented carbide
including a metallic binder comprising greater than an impurities
concentration of one or more elements selected from the group
consisting of platinum, palladium, rhenium, rhodium, and ruthenium.
As discussed herein in relation to certain non-limiting
embodiments, the present inventors discovered that providing a
combined concentration of platinum, palladium, rhenium, rhodium,
and ruthenium in the metallic binder in the range of 0.1 to 10
weight percent, based on the total weight of the cemented carbide,
significantly improves critical mechanical properties of the
cutting inserts, thereby increasing the resistance of the cutting
inserts to wear and prolonging the period before cutting insert
failure and the need for repairing or replacing the earth boring
bit. The metallic binder may include one, two, three, four, or all
of platinum, palladium, rhenium, rhodium, and ruthenium, but the
combined weight percentages of these elements in the metallic
binder is at least 0.1 weight percent and is no greater than 10
weight percent. In other words, in certain embodiments the metallic
binder may entirely lack one or more of platinum, palladium,
rhenium, rhodium, and ruthenium, but the combined concentration of
any such elements that are present is within the indicated
concentration range.
[0028] Several terms used in the present description and in the
claims have the following meanings.
[0029] As used herein, the term "cemented carbide" refers to a
composite material including a discontinuous, dispersed phase
including hard grains, and a continuous phase of a relatively soft
metallic binder. In many conventional cemented carbides the hard
grains of the dispersed phase comprise transition metal carbide,
wherein the transition metal is selected from, for example,
titanium, vanadium, chromium, zirconium, hafnium, molybdenum,
niobium, tantalum, tungsten, solid solutions of two or more
thereof, and solutions of two or more thereof. The metallic binder
typically comprises at least one of cobalt, a cobalt alloy, nickel,
a nickel alloy, iron, and an iron alloy. The metallic binder binds
or "cements" the dispersed hard grains together, and the composite
exhibits an advantageous combination of the physical properties of
the discontinuous and continuous phases. FIG. 3 is a micrograph of
the microstructure of a representative cemented carbide. The
lighter regions are dispersed hard grains of tungsten carbide, and
the darker region is a continuous region of cobalt binder cementing
together the hard tungsten carbide grains, thereby forming the
composite. In various non-limiting embodiments, the metallic binder
of the cemented carbide may also include one or more additives
selected from chromium, molybdenum, boron, tungsten, tantalum,
titanium, niobium, silicon, aluminum, copper, and manganese. In
certain non-limiting embodiments, the metallic binder of a cemented
carbide may include up to a total of 20 weight percent of the
additives, based on the total weight of the binder. In other
non-limiting embodiments, the metallic binder of a cemented carbide
may include a total of up to 15 weight percent, up to 10 weight
percent, or up to 5 weight percent of the additives, based on the
total weight of the binder. As will be understood, both the
dispersed phase and the metallic binder may include incidental
impurities.
[0030] Numerous cemented carbide types or "grades" are produced by
varying parameters that may include the composition of the
materials in the dispersed and/or continuous phases, the average
size of the hard grains of the dispersed phase, and/or the volume
fractions of the discontinuous and continuous phases. Cemented
carbides including a dispersed phase of tungsten carbide grains and
a cobalt or cobalt alloy binder are the most commercially important
of the commonly available cemented carbide grades. Conventional
cemented carbide grades are available as powders (often referred to
"cemented carbide powders"). The powders may be processed to a
final monolithic form using, for example, conventional
press-and-sinter techniques or other techniques known for producing
cemented carbides from precursor cemented carbide powder
grades.
[0031] Conventional cemented carbide grades including a
discontinuous, dispersed phase of tungsten carbide grains and a
continuous phase of cobalt binder exhibit advantageous combinations
of ultimate tensile strength, fracture toughness, and wear
resistance. As is known in the art, "fracture toughness" refers to
the ability of a material to absorb energy and deform plastically
before fracturing. "Toughness" is proportional to the area under
the stress-strain curve from the origin to the breaking point (see
MCGRAW-HILL DICTIONARY OF SCIENTIFIC AND TECHNICAL TERMS (5.sup.th
ed. 1994)) and may be evaluated using known mechanical test
techniques. "Wear resistance" refers to the ability of a material
to withstand damage to its surface. Wear generally involves
progressive loss of material from an article due to relative motion
between the article and a contacting surface or substance. See
METALS HANDBOOK DESK EDITION (2d ed. 1998).
[0032] Certain non-limiting embodiments of earth boring cutting
inserts described herein include a working portion. As used herein,
a "working portion" refers to the portion of an earth boring
cutting insert that principally contacts the rock, dirt, or other
material to be removed or separated by the earth boring bit on
which the cutting insert is mounted. In contrast to the working
portion, an earth boring cutting insert also may include a "body
portion" which, as used herein, refers to a portion of the earth
boring cutting insert that supports the working portion. The body
portion and working portion may be, but need not be, regions of a
unitary earth boring cutting insert. It will be understood that in
certain embodiments of an earth boring cutting insert according to
the present invention, there may not exist a clear line of division
between the working portion and the body portion of the cutting
insert. In such embodiments, however, an ordinarily skilled person
will recognize a difference between the portions in that the
working portion will be adapted to principally carry out the
intended function of the cutting insert, while the body portion
will be adapted to principally support the working portion.
Alternatively, the working portion and body portion may be formed
of different materials and otherwise securely attached or bonded
together so that the body portion provides the requisite support
for the working portion when the cutting insert is in service.
[0033] It is generally understood that properties of cemented
carbides that largely determine overall performance of earth boring
cutting inserts (and hence, of the earth boring bit on which the
cutting inserts are mounted) are wear resistance and fracture
toughness. In order to optimize performance of earth boring cutting
inserts, it is desirable to obtain the highest fracture toughness
for a given level of wear resistance, and vice versa. As noted
above, the wear resistance and fracture toughness properties of
cemented carbides are largely influenced by two parameters of the
material's microstructure, namely, the average hard grain size and
the weight or volume fraction of the hard grains and/or the
metallic binder. In general, the hardness and wear resistance
increases as the average hard grain size decreases and/or the
weight or volume fraction of the metallic binder content of the
cemented carbide decreases. On the other hand, fracture toughness
increases as the average hard grain size increases and/or the
weight or volume fraction of the metallic binder of the cemented
carbide increases. Thus, it has been believed that one invariably
experiences a trade-off between wear resistance and fracture
toughness when selecting a cemented carbide grade for any earth
boring application.
[0034] The trade-off between wear resistance and fracture toughness
in certain conventional cemented carbides is illustrated in Table 1
and in FIG. 4. Table 1 provides a listing of conventional WC--Co
based cemented carbide grades, identified as Grade A through Grade
L, that are commonly used in earth boring cutting inserts and are
commercially available from ATI Firth Sterling, Houston, Tex. Table
1 also lists the following for each grade: the commercial grade
designation used by ATI Firth Sterling; the average WC grain size;
the cobalt binder content (based on total weight of the cemented
carbide); hardness; and density. The cobalt contents listed in
Table 1 are weight percentages based on the total weight of the
cemented carbide. The balance of each grade listed in Table 1 is
tungsten carbide grains. The listed cemented carbide grades include
WC grains having an average diameter (when viewed in a prepared
microstructural specimen) in the range of about 4 to about 8 .mu.m,
a cobalt binder content in the range of about 8 to about 17 weight
percent, with the balance constituting the WC grains. FIG. 4 is a
graph plotting the relationship between wear resistance and
fracture toughness for the cemented carbide grades A-L listed in
Table 1. Fracture toughness was evaluated using a test method
substantially equivalent to ASTM B 771-87(2006), "Standard Test
Method for Short Rod Fracture Toughness of Cemented Carbides". Wear
resistance was evaluated according to ASTM B 611-85(2005),
"Standard Test Method for Abrasive Wear Resistance of Cemented
Carbides".
TABLE-US-00001 TABLE 1 Average WC Commercial Grain Co Hard- Grade
Size Content WC ness Density Grade Designation (.mu.m) (wt %)
Content (HRA) (g/cm.sup.3) A .sup. 45B 5.5 16.0 Bal. 85.5 13.90 B
147 7.0 14.0 Bal. 86.0 14.10 C 120 6.5 12.0 Bal. 86.6 14.30 D 231
5.5 10.0 Bal. 87.8 14.50 E 1865 6.5 9.0 Bal. 87.8 14.65 F 931 5.0
11.0 Bal. 87.8 14.40 G 241 4.5 10.0 Bal. 88.5 14.50 H 941 4.5 11.0
Bal. 88.5 14.40 J 91 5.0 8.5 Bal. 89.3 14.60 K 1550 5.0 7.5 Bal.
89.2 14.75 L 290 4.0 6.0 Bal. 90.3 14.90
[0035] As confirmed by the least fit curve plotted from the data
points in FIG. 4 for grades A through L, fracture toughness
decreases as wear resistance increases, and vice versa. Also, as is
evident from FIG. 4, all of the data points plotting the fracture
toughness and wear resistance values for each of cemented carbide
grades A-L lie within a relatively narrow band about the least fit
curve. Given the relationship shown in FIG. 4, metallurgists and
design engineers face the dilemma of having to compromise on one or
the other of wear resistance and fracture toughness when selecting
a cemented carbide grade for earth boring applications.
[0036] The present inventors undertook efforts to improve the
performance of cemented carbide earth boring cutting inserts by
modifying the composition of the cemented carbide. With reference
to the cemented carbide grades in FIG. 4, for example, the present
inventors concluded that the performance of earth boring cutting
inserts including those cemented carbides could be significantly
enhanced if the individual data points in FIG. 4 could be displaced
in an easterly direction (i.e., increasing wear resistance without
any loss in fracture toughness) and/or in a northerly direction
(i.e., increasing fracture toughness without any loss in wear
resistance). Thus, the arrows in FIG. 4 indicate a desired
direction in which the individual data points (representing the
combination of wear resistance and fracture toughness of the
individual grades) might be displaced in order to enhance
performance. More generally, the present inventors sought to
identify modifications to composition of cemented carbide grades so
as to increase wear resistance without reducing fracture toughness
and/or increase fracture toughness without reducing wear
resistance.
[0037] The present inventors discovered that earth boring cutting
inserts including cemented carbide in which a platinum group metal
such as ruthenium is added as an alloying addition to the metallic
binder of the cemented carbide exhibit significantly improved
properties important for earth boring applications relative to
identical cemented grades lacking the addition. For example, the
present inventors determined through experimentation and testing
that WC--Co based cemented carbide grades based on average WC grain
sizes and Co contents comparable to certain conventional cemented
carbide grades listed above in Table 1, but which have been
modified to include the platinum group metal ruthenium as an
alloying addition to the cobalt-based metallic binder of the
cemented carbides, provide substantially superior combinations of
wear resistance and facture toughness compared to the corresponding
conventional grades.
[0038] The experimental ruthenium-containing cemented carbides
listed in Table 2 below, identified as R-1 through R-4, were
prepared. The cobalt and ruthenium contents listed in Table 2 are
in weight percentages based on the total weight of the cemented
carbide. Each of grades R-1 through R-4 was prepared in
substantially the same way, using standard press-and-sinter
techniques commonly used to produce cemented carbides for earth
boring cutting inserts. In preparing each of the experimental
grades, WC--Co, cobalt, and ruthenium powders were blended to
provide a homogenous powder blend having the desired ratio of WC
particles, cobalt, and ruthenium. A portion of the powder blend was
then consolidated to a green compact in rigid tooling using a
compacting pressure of about 20,000 psi. The green compact was
sintered in an over-pressure sintering furnace (also known as a
"Sinter-Hip" furnace) at a final temperature of 1400.degree. C.,
and was held at the final temperature for about 90 minutes. The
sintering step resulted in inter-diffusion of the ruthenium and
cobalt, producing a continuous phase of metallic binder including
cobalt and ruthenium, binding together a dispersed phase of hard
tungsten carbide grains. The microstructures of experimental grades
R-1 through R-4 are shown in FIGS. 6A-D, respectively. The dark
regions in each micrograph are tungsten carbide grains,
constituting the dispersed phase of the material, and the light
regions represent the ruthenium-containing cobalt binder of the
material. Table 2 provides information on the average WC grain size
and the composition of experimental grades R-1 through R-4.
TABLE-US-00002 TABLE 2 Average WC Co Content Ru Content Grade Grain
Size (.mu.m) (wt %) (wt %) WC content R-1 4.5 8.7 1.3 Balance R-2
5.5 10.2 1.8 Balance R-3 5.5 11.9 2.1 Balance R-4 5.5 14.0 2.1
Balance
[0039] Suitable test specimens were prepared from the sintered
blanks of experimental grades R-1 through R4 and tested for
fracture toughness and wear resistance. Table 3 lists measured
mechanical properties of the experimental grades, and FIG. 5
includes data points R-1 through R-4 plotting the relationship
between wear resistance and fracture toughness for the
corresponding experimental grade. Fracture toughness was evaluated
using a test method substantially equivalent to ASTM B
771-87(2006). Wear resistance was evaluated according to ASTM B
611-85(2005). FIG. 5 also includes the data points and the curve
presented in FIG. 4 for conventional grades A-L. The improvement in
performance achieved by the ruthenium-containing experimental
grades is evident from FIG. 5. Each of the data points for the
experimental grades is shifted away significantly from the least
fit curve plotted from the data points for the conventional grades.
It will understood that a least fit curve generated based on the
four data points R-1 through R-4 in FIG. 5, for example, would be
in a position shifted in a northeasterly direction from the curve
in FIG. 5 associated with the data points for the conventional
cemented carbide grades. Thus, with regard to a least fit curve for
data points R-1 through R-4, for any given fracture toughness, the
associated wear resistance would be significantly greater than on
the curve shown in FIG. 5 for the conventional grades. Also, with
regard to a least fit curve for data points R-1 through R-4, for
any given wear resistance, the associated fracture toughness would
be significantly greater than on the curve shown in FIG. 5 for the
conventional grades.
TABLE-US-00003 TABLE 3 Fracture Wear Hardness Density Toughness
Resistance Grade (HRA) (g/cm.sup.3) (ksi. in) (krevs/cm.sup.3) R-1
88.9 14.5 12.6 9.3 R-2 87.7 14.4 15.5 7.5 R-3 87.1 14.2 15.9 6.3
R-4 86.4 14.0 17.3 4.6
[0040] Thus, the addition of the platinum group metal ruthenium
allows for cemented carbide grades with fracture toughness at least
equivalent to conventional grades, but with greater wear
resistance, and vice versa. Thus, for example, greater wear
resistance may be achieved without a corresponding reduction in
fracture toughness, and great fracture toughness may be achieved
without a reduction in wear resistance. Including embodiments of
the novel cemented carbide grades in earth boring cutting inserts
will increase the service life of the cutting inserts and the earth
boring bit as a whole. This will reduce the frequency of cutting
insert replacement, making extraction of the drill string a less
frequent event, thereby lowering downtime and costs.
[0041] Accordingly, an aspect of the present disclosure is directed
to an earth boring cutting insert including a cemented carbide
comprising a metallic binder including ruthenium. The inventors
have determined that the addition of ruthenium to the metallic
binder improves the performance of the cutting inserts, as shown in
the experimentation described above. Prior work indicates to the
present inventors that the other platinum group metals rhodium,
palladium, and platinum, as well as the element rhenium (positioned
in an adjacent column of the Periodic Table) can have effects
similar to those of the platinum group metal ruthenium.
Accordingly, based on the results of the present inventors' testing
involving additions of ruthenium, the present disclosure also
contemplates the possible addition of one or more of ruthenium,
platinum, palladium, rhenium, and rhodium to a metallic binder of
cemented carbide comprised in an earth boring cutting insert to
achieve the advantages discussed herein.
[0042] To further illustrate the scope of the present invention,
various possible (prophetic) non-limiting embodiments of cemented
carbides that may be included in the earth boring cutting inserts
and bits according to the present invention, numbered as Examples
1-10, are provided in Table 4. All values listed in Table 4 are
weight percentages based on the total weight of the cemented
carbide. Grains comprising the dispersed phase of the cemented
carbides include tungsten carbide (WC), titanium carbide (TiC),
tantalum/niobium carbide (Ta,NbC), and/or chromium carbide
(Cr.sub.2C.sub.3). The metallic binder of the cemented carbides
includes cobalt, nickel, iron, ruthenium, rhenium, platinum, and/or
palladium.
TABLE-US-00004 TABLE 4 Ex. WC TiC Ta,NbC Cr.sub.2C.sub.3 Co Ni Fe
Ru Re Pt Pd 1 89.1 -- -- -- 9.5 -- -- 1.4 -- -- -- 2 89.1 -- -- --
9.1 -- -- -- 1.8 -- -- 3 89.1 -- -- -- 10.2 -- -- -- -- 0.7 -- 4
89.1 -- -- -- 10.2 -- -- -- -- -- 0.7 5 89.1 -- -- -- 6.1 3.4 --
1.4 -- -- -- 6 89.1 -- -- -- 6.1 1.7 1.7 1.4 -- -- -- 7 68.3 6.5
14.0 -- 10.0 -- -- 1.2 -- -- -- 8 67.7 6.5 14.0 10.0 -- -- -- 1.8
-- -- 9 89.4 -- -- 0.8 8.0 -- -- -- 1.8 -- -- 10 89.4 -- -- 0.8 7.3
-- -- -- 2.5 --
[0043] In certain non-limiting embodiments of earth boring cutting
inserts according the present disclosure, the cutting inserts
include a cemented carbide that comprises a dispersed phase
including hard grains, and a continuous phase of a metallic binder.
The earth boring cutting inserts may be, for example, adapted for
use on rotary-cone earth boring bits and/or percussion bits
(including, for example, hammer bits). The hard grains may include
metal carbide comprising at least one transition metal selected
from titanium, vanadium, chromium, zirconium, niobium, molybdenum,
hafnium, tantalum, and tungsten. In certain non-limiting
embodiments, the hard grains of the dispersed phase comprise at
least one of titanium carbide, vanadium carbide, chromium carbide,
zirconium carbide, niobium carbide, molybdenum carbide, hafnium
carbide, tantalum carbide, and tungsten carbide. In certain
non-limiting embodiments, the hard grains of the dispersed phase
comprise tungsten carbide. In certain non-limiting embodiments, the
metallic binder comprises at least one of cobalt, a cobalt alloy,
nickel, a nickel alloy, iron, and an iron alloy, and a combined
concentration of platinum, palladium, rhenium, rhodium, and
ruthenium in the metallic binder that is 0.1 to 10 weight percent,
based on the total weight of the cemented carbide. In certain
non-limiting embodiments, the metallic binder of the cemented
carbide comprises 0.1 to 10 weight percent ruthenium. In certain
other non-limiting embodiments, the metallic binder of the cemented
carbide comprises ruthenium and cobalt. In yet other non-limiting
embodiments, the metallic binder of the cemented carbide comprises
a combined concentration of platinum, palladium, rhenium, rhodium,
and ruthenium that is 0.3 to 7 weight percent, based on the total
weight of the cemented carbide. In certain other embodiments, the
metallic binder comprises a combined concentration of platinum,
palladium, rhenium, rhodium, and ruthenium in the metallic binder
that is 0.5 to 5 weight percent, based on the total weight of the
cemented carbide. In certain non-limiting embodiments of earth
boring cutting inserts according the present disclosure, the
cutting inserts include a cemented carbide comprising 2 to 40
weight percent of the metallic binder and 60 to 98 weight percent
of the dispersed phase.
[0044] In certain non-limiting embodiments of earth boring cutting
inserts according the present disclosure, the cutting inserts
include a cemented carbide wherein the hard grains of the dispersed
phase of the cemented carbide comprise, consist essentially of, or
consist of tungsten carbide; and the metallic binder comprises
cobalt and greater than an impurities concentration of
ruthenium.
[0045] Non-limiting embodiments of earth boring bits according to
the present disclosure may include a working portion and a body
portion. In certain embodiments, the working portion includes a
shape selected from an ovoid shape, a ballistic shape, a chisel
shape, a multi-dome shape, and a conical shape.
[0046] In certain embodiments, an earth boring cutting insert
according to the present disclosure includes a first region
comprising a first cemented carbide, and a second region comprising
a second cemented carbide. The first cemented carbide includes a
metallic binder including a combined concentration of platinum,
palladium, rhenium, rhodium, and ruthenium in the metallic binder
that is 0.1 to 10 weight percent, based on the total weight of the
cemented carbide. The second cemented carbide includes a metallic
binder that includes a combined concentration of platinum,
palladium, rhenium, rhodium, and ruthenium that is less than
combined concentration of platinum, palladium, rhenium, rhodium,
and ruthenium in the metallic binder of the first cemented carbide.
In certain embodiments, the metallic binder of the first cemented
carbide comprises a combined concentration of platinum, palladium,
rhenium, rhodium, and ruthenium in the metallic binder that is 0.3
to 7 weight percent, based on the total weight of the first
cemented carbide. In certain other embodiments, the metallic binder
of the first cemented carbide comprises a combined concentration of
platinum, palladium, rhenium, rhodium, and ruthenium in the
metallic binder that is 0.5 to 5 weight percent, based on the total
weight of the first cemented carbide. In certain non-limiting
embodiments, the metallic binder of the first cemented carbide
includes 0.1 to 10 weight percent ruthenium, or 0.3 to 7 weight
percent ruthenium, or 0.5 to 5 weight percent ruthenium, based on
the weight of the first cemented carbide. In further embodiments,
the metallic binder of the second cemented carbide includes no
greater than an impurities concentration of platinum, palladium,
rhenium, rhodium, and ruthenium. Also, in certain embodiments, the
metallic binder of the second cemented carbide does not include
ruthenium.
[0047] In non-limiting embodiments directed to an earth boring
cutting insert according to the present disclosure including a
first region comprising a first cemented carbide, and a second
region comprising a second cemented carbide, the first cemented
carbide and the second cemented carbide may each individually
comprise: a dispersed phase including hard grains of metal carbide
comprising at least one transition metal selected from titanium,
vanadium, chromium, zirconium, niobium, molybdenum, hafnium,
tantalum, and tungsten; and a continuous phase of a metallic binder
comprising at least one of cobalt, a cobalt alloy, nickel, a nickel
alloy, iron, and an iron alloy. According to one non-limiting
embodiment of an earth boring cutting insert according to the
present disclosure including a first region comprising a first
cemented carbide, and a second region comprising a second cemented
carbide, a dispersed phase of the first cemented carbide comprise
tungsten carbide, and a metallic binder of the first cemented
carbide comprises cobalt; and a dispersed phase of the second
cemented carbide comprises tungsten carbide, and a metallic binder
of the second cemented carbide comprises cobalt.
[0048] In non-limiting embodiments directed to an earth boring
cutting insert according to the present disclosure including a
first region comprising a first cemented carbide, and a second
region comprising a second cemented carbide, the first region
includes a working portion of the cutting insert. Possible shapes
included in the working portion of the earth boring cutting insert
include, for example, an ovoid shape, a ballistic shape, a chisel
shape, a multi-dome shape, and a conical shape. The earth boring
cutting insert may be adapted for use with at least one of a
rotary-cone earth boring bit and a percussion bit (including, for
example, a hammer bit).
[0049] In certain non-limiting embodiments of earth boring cutting
inserts according the present disclosure, the cutting inserts
include a working portion comprising a first cemented carbide, and
a body portion comprising a second cemented carbide. The first
cemented carbide includes a dispersed phase of hard grains
including metal carbide comprising at least one transition metal
selected from titanium, vanadium, chromium, zirconium, niobium,
molybdenum, hafnium, tantalum, and tungsten. The first cemented
carbide also includes a continuous phase of a metallic binder
comprising at least one of cobalt, a cobalt alloy, nickel, a nickel
alloy, iron, and an iron alloy, and a combined concentration of
platinum, palladium, rhenium, rhodium, and ruthenium that is 0.1 to
10 weight percent, based on the total weight of the cemented
carbide. In certain embodiments of the earth boring cutting insert,
the metallic binder of the first cemented carbide comprises a
combined concentration of platinum, palladium, rhenium, rhodium,
and ruthenium in the metallic binder that is 0.3 to 7 weight
percent, based on the total weight of the first cemented carbide.
In certain embodiments of the earth boring cutting insert, the
metallic binder of the first cemented carbide comprises a combined
concentration of platinum, palladium, rhenium, rhodium, and
ruthenium in the metallic binder that is 0.5 to 5 weight percent,
based on the total weight of the first cemented carbide. In certain
non-limiting embodiments, the metallic binder of the first cemented
carbide includes 0.1 to 10 weight percent ruthenium, 0.3 to 7
weight percent ruthenium, or 0.5 to 5 weight percent ruthenium,
based on the weight of the first cemented carbide. The second
cemented carbide includes a dispersed phase of hard grains
including metal carbide comprising at least one transition metal
selected from titanium, vanadium, chromium, zirconium, niobium,
molybdenum, hafnium, tantalum, and tungsten. The second cemented
carbide also includes a continuous phase of a metallic binder
comprising at least one of cobalt, a cobalt alloy, nickel, a nickel
alloy, iron, and an iron alloy, and a combined concentration of
platinum, palladium, rhenium, rhodium, and ruthenium in the
metallic binder that is less than the combined concentration of
platinum, palladium, rhenium, rhodium, and ruthenium in the
metallic binder of the first cemented carbide.
[0050] In certain embodiments of an earth boring cutting insert
according to the present disclosure including a working portion
comprising a first cemented carbide, and a body portion comprising
a second cemented carbide, the dispersed phase of the first
cemented carbide comprises tungsten carbide, and the metallic
binder of the first cemented carbide comprises cobalt and greater
than an impurities concentrations of one or more elements selected
from the group consisting of platinum, palladium, rhenium, rhodium,
and ruthenium. In certain embodiments of an earth boring cutting
insert including a working portion comprising a first cemented
carbide, and a body portion comprising a second cemented carbide,
the dispersed phase of the second cemented carbide comprises
tungsten carbide, and the metallic binder of the second cemented
carbide comprises cobalt.
[0051] FIGS. 7(a)-(e) are photographs showing aspects of an
embodiment of an earth boring cutting insert according to the
present disclosure having a dome-shaped tip and including a first
region including a first cemented carbide, and a second region
including a second cemented carbide. FIG. 6(a) is a cross-sectional
view (taken through a longitudinal axis) and FIG. 6(e) is an
exterior view of earth boring cutting insert 50. Earth boring
cutting insert 50 includes a first region including a first
cemented carbide 52, and a second region including a second
cemented carbide 54. As best shown in FIG. 6(a), the first cemented
carbide 52 and the second cemented carbide 54 meet at a transition
zone 56. FIG. 6(b) is a micrograph showing the microstructure of
the dome-shaped tip region. FIG. 6(c) is a micrograph showing the
microstructure in the transition zone, wherein the first cemented
carbide meets the second cemented carbide. FIG. 6(d) is a
micrograph showing the microstructure of the second cemented
carbide in the second region. The first cemented carbide 52 may
include a dispersed phase including hard grains of carbide of at
least one transition metal selected from titanium, vanadium,
chromium, zirconium, niobium, molybdenum, hafnium, tantalum, and
tungsten; and a continuous phase of a metallic binder comprising at
least one of cobalt, a cobalt alloy, nickel, a nickel alloy, iron,
and an iron alloy, and a combined concentration of platinum,
palladium, rhenium, rhodium, and ruthenium that is 0.1 to 10 weight
percent, based on the total weight of the cemented carbide. The
second cemented carbide 54 may include, for example, a dispersed
phase of hard grains including metal carbide comprising at least
one transition metal selected from titanium, vanadium, chromium,
zirconium, niobium, molybdenum, hafnium, tantalum, and tungsten;
and a continuous phase of a metallic binder comprising at least one
of cobalt, a cobalt alloy, nickel, a nickel alloy, iron, and an
iron alloy, and a combined concentration of platinum, palladium,
rhenium, rhodium, and ruthenium in the metallic binder that is less
than a combined concentration of platinum, palladium, rhenium,
rhodium, and ruthenium in the metallic binder of the first cemented
carbide. In a more particular embodiment, both the first cemented
carbide and the second cemented carbide include a dispersed phase
comprising hard grains of tungsten carbide; the first cemented
carbide includes a continuous phase of a metallic binder including
cobalt and a combined concentration of platinum, palladium,
rhenium, rhodium, and ruthenium in the metallic binder that is 0.1
to 10 weight percent, based on the total weight of the cemented
carbide; and the second cemented carbide includes 0 up to no more
than an impurities concentration of each of platinum, palladium,
rhenium, rhodium, and ruthenium.
[0052] An advantage of a multi-region earth boring cutting insert
according to the present disclosure, such as cutting insert 50
shown in FIGS. 7(a)-(e) is that a working portion of the cutting
insert may be composed of a first cemented carbide that includes
greater ruthenium than a second cemented carbide positioned in body
portion of the cutting insert. Given the cost of the alloying
elements, utilizing a cemented carbide including a significant
level of platinum, palladium, rhenium, rhodium, and/or ruthenium
only in regions of the cutting insert that will be subjected to
significant wear forces may reduce the materials cost associate
with producing the cutting inserts.
[0053] The present disclosure also is directed to earth boring
bits, such as, for example, rotary-cone earth boring bits and
percussion bits (including, for example, hammer bits), including
one or more earth boring cutting inserts according to the present
disclosure mounted thereon. In one non-limiting embodiment
according to the present disclosure, an earth boring bit includes a
bit body; and at least one earth boring cutting insert comprising a
metallic binder including at least one of platinum, palladium,
rhenium, rhodium, and ruthenium. In certain non-limiting
embodiments, the at least one earth boring bit includes a cemented
carbide comprising: a dispersed phase including hard grains
including metal carbide comprising at least one transition metal
selected from titanium, vanadium, chromium, zirconium, niobium,
molybdenum, hafnium, tantalum, and tungsten; and a continuous phase
of a metallic binder comprising at least one of cobalt, a cobalt
alloy, nickel, a nickel alloy, iron, and an iron alloy, and a
combined concentration of platinum, palladium, rhenium, rhodium,
and ruthenium in the metallic binder that is 0.1 to 10 weight
percent, based on the total weight of the cemented carbide. In
certain embodiments, the metallic binder comprises a combined
concentration of platinum, palladium, rhenium, rhodium, and
ruthenium in the metallic binder that is 0.3 to 7 weight percent,
based on the total weight of the cemented carbide. In certain
embodiments, the metallic binder comprises a combined concentration
of platinum, palladium, rhenium, rhodium, and ruthenium in the
metallic binder that 0.5 to 5 weight percent, based on the total
weight of the cemented carbide. In certain embodiments, the
metallic binder comprises 0.1 to 10 weight percent ruthenium, 0.3
to 7 weight percent ruthenium, or 0.5 to 5 weight percent
ruthenium, based on the total weight of the cemented carbide. In
certain non-limiting embodiments, the cemented carbide comprises 2
to 40 weight percent of the metallic binder and 60 to 98 weight
percent of the dispersed phase. In certain embodiments, the hard
grains of the dispersed phase comprise at least one of titanium
carbide, vanadium carbide, chromium carbide, zirconium carbide,
niobium carbide, molybdenum carbide, hafnium carbide, tantalum
carbide, and tungsten carbide. In certain embodiments, the hard
grains of the dispersed phase comprise tungsten carbide, and the
metallic binder comprises cobalt and ruthenium.
[0054] According to certain non-limiting embodiments, an earth
boring bit according to the present disclosure, which may be, for
example, a rotary-cone earth boring bit or a percussion bit,
includes at least one earth boring cutting insert that comprises a
first region including a first cemented carbide, and a second
region including a second cemented carbide. The first cemented
carbide includes a metallic binder comprising a combined
concentration of platinum, palladium, rhenium, rhodium, and
ruthenium in the metallic binder that is 0.1 to 10 weight percent,
based on the total weight of the cemented carbide. The second
cemented carbide includes a metallic binder that includes no more
than an impurities concentration of each of platinum, palladium,
rhenium, rhodium, and ruthenium, or includes a combined
concentration of platinum, palladium, rhenium, rhodium, and
ruthenium that is less than the concentration of ruthenium in the
metallic binder of the first cemented carbide. In certain
embodiments, the metallic binder of the first cemented carbide
comprises a combined concentration of platinum, palladium, rhenium,
rhodium, and ruthenium in the metallic binder that is 0.3 to 7
weight percent, based on the total weight of the first cemented
carbide. In certain other embodiments, the metallic binder of the
first cemented carbide comprises a combined concentration of
platinum, palladium, rhenium, rhodium, and ruthenium in the
metallic binder that is 0.5 to 5 weight percent, based on the total
weight of the first cemented carbide. In certain embodiments, the
metallic binder of the second cemented carbide includes no greater
than an impurities concentration of a platinum, palladium, rhenium,
rhodium, and ruthenium. In certain embodiments, the metallic binder
of the second cemented carbide does not include platinum,
palladium, rhenium, rhodium, and/or ruthenium in the metallic
binder. In certain embodiments, the first cemented carbide and the
second cemented carbide each individually comprise: a dispersed
phase including hard grains including a metal carbide comprising at
least one transition metal selected from titanium, vanadium,
chromium, zirconium, niobium, molybdenum, hafnium, tantalum, and
tungsten; and a continuous phase of a metallic binder comprising at
least one of cobalt, a cobalt alloy, nickel, a nickel alloy, iron,
and an iron alloy. In certain embodiments, the dispersed phase of
the first cemented carbide comprise tungsten carbide, and the
metallic binder of the first cemented carbide comprises cobalt; and
the dispersed phase of the second cemented carbide comprises
tungsten carbide, and the metallic binder of the second cemented
carbide comprises cobalt.
[0055] According to certain non-limiting embodiments, an earth
boring bit according to the present disclosure includes at least
one earth boring cutting insert comprising a working portion
comprising a first cemented carbide, and a body portion comprising
a second cemented carbide. The first cemented carbide includes a
dispersed phase of hard grains including a carbide of at least one
transition metal selected from titanium, vanadium, chromium,
zirconium, niobium, molybdenum, hafnium, tantalum, and tungsten.
The first cemented carbide also includes a continuous phase of a
metallic binder comprising at least one of cobalt, a cobalt alloy,
nickel, a nickel alloy, iron, and an iron alloy, and a combined
concentration of platinum, palladium, rhenium, rhodium, and
ruthenium in the metallic binder that is 0.1 to 10 weight percent,
based on the total weight of the cemented carbide. The second
cemented carbide includes a dispersed phase of hard grains
including metal carbide comprising at least one transition metal
selected from titanium, vanadium, chromium, zirconium, niobium,
molybdenum, hafnium, tantalum, and tungsten. The second cemented
carbide includes a continuous phase of a metallic binder comprising
at least one of cobalt, a cobalt alloy, nickel, a nickel alloy,
iron, and an iron alloy, and a combined concentration of platinum,
palladium, rhenium, rhodium, and ruthenium in the metallic binder
that is less than a combined concentration of platinum, palladium,
rhenium, rhodium, and ruthenium in the metallic binder of the first
cemented carbide. In certain embodiments, the metallic binder of
the first cemented carbide comprises a combined concentration of
platinum, palladium, rhenium, rhodium, and ruthenium in the
metallic binder that is 0.3 to 7 weight percent, based on the total
weight of the first cemented carbide. In certain embodiments, the
metallic binder of the first cemented carbide comprises a combined
concentration of platinum, palladium, rhenium, rhodium, and
ruthenium in the metallic binder that is 0.5 to 5 weight percent,
based on the total weight of the first cemented carbide. In other
embodiments, the dispersed phase of the first cemented carbide
comprises tungsten carbide, and the metallic binder of the first
cemented carbide comprises cobalt. In certain embodiments, the
dispersed phase of the second cemented carbide comprises tungsten
carbide, and the metallic binder of the second cemented carbide
comprises cobalt.
[0056] The various earth boring cutting inserts and earth boring
bits according to the present disclosure may be made by any method
of manufacturing such articles, whether known now or hereinafter
developed. For example, earth boring cutting inserts according to
the present disclosure may be made by first using conventional
press-and-sinter manufacturing techniques to provide a billet or
predetermined shape of cemented carbide. As understood by
ordinarily skilled artisans, press-and-sinter techniques may
include a step of producing a metallurgical powder blend having the
desired composition. Here, such a powder blend may have the
composition of the desired cemented carbide material, including
elemental powders and/or master alloy powders providing the desired
elements in the appropriate proportions. All or a portion of the
powder blend is compacted under high pressure to provide a green
compact. As is known in the art, the green compact may by
pre-sintered to provide a "brown" compact, which may be machined to
provide particular features. The compact is sintered at high
temperature for a period of time sufficient to suitably consolidate
and densify the compact, thereby providing a billet or
pre-determined shape of sintered cemented carbide material. The
sintered compact may be machined to provide a cutting insert having
the desired shape and including particular features. Regarding
earth boring cutting bits, the bit bodies of such bits may be made
using any conventional process. For example, bit bodes formed of
metallic alloy may be machined from a perform of the desired alloy
material. Cemented carbide bit bodies may be produced using known
manufacturing techniques. One or more earth boring cutting inserts
may be mounted on a particular bit body to provide an earth boring
bit.
[0057] An alternative to using elemental or master alloy powders in
a powder mix as the means for including concentrations of one or
more of platinum, palladium, rhenium, rhodium, and ruthenium in a
metallic binder according to the present disclosure is to diffuse
one or more of these elements into the metallic binder of cemented
carbide earth boring inserts manufactured in a conventional
press-and-sinter manner, as outlined above. Suitable techniques
that may be used to diffuse elements into the metallic binder of a
cemented carbide are known in the art and include, for example,
techniques described in U.S. Patent Application Publication No. US
2011/0052931 A1, the entire disclosure of which is hereby
incorporated herein by reference. In the event such diffusion
techniques are used, a near-surface region of the cemented carbide
will include a concentration gradient of the diffused element or
elements in the metallic binder of the material.
[0058] Those having ordinary skill, on reading the present
disclosure, may, without undue effort, identify and implement
suitable methods for producing earth boring cutting inserts and
earth boring bits having the characteristics described herein.
Accordingly, further discussion of possible manufacturing
techniques need not be provided herein.
[0059] This specification has been written with reference to
various non-limiting and non-exhaustive embodiments. However, it
will be recognized by persons having ordinary skill in the art that
various substitutions, modifications, or combinations of any of the
disclosed embodiments (or portions thereof) may be made within the
scope of this specification. Thus, it is contemplated and
understood that this specification supports additional embodiments
not expressly set forth herein. Such embodiments may be obtained,
for example, by combining, modifying, or reorganizing any of the
disclosed steps, components, elements, features, aspects,
characteristics, limitations, and the like, of the various
non-limiting embodiments described in this specification. In this
manner, Applicant reserves the right to amend the claims during
prosecution to add features as variously described in this
specification, and such amendments comply with the requirements of
35 U.S.C. .sctn.112, first paragraph, and 35 U.S.C.
.sctn.132(a).
* * * * *