Note: Descriptions are shown in the official language in which they were submitted.
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IiATRI7C FOR l, HARD COMPOSITE
BACKGROUND OF THE INVENTION
The invention pertains to a hard composite
comprising a metal matrix and one or more discrete hard
elements held therein wherein the hard composite can be~
useful as a cutter or a wear member. More particularly,
the invention pertains to a~diamond composite
comprising a matrix composed of carbide-based
particulates bonded together by an infiltrant metal
with one or more discrete diamond-based elements held
therein. It should be understood that the diamond-based
element could comprise a discrete-diamond composite or
polycrystalline diamond composite having a substrate
with a layer of polycrystalline diamond thereon. Some
types of tungsten carbide that are appropriate for use
in matrix tools include a macrocrystalline tungsten
carbide, a crushed sintered cemented macrocrystalline
tungsten carbide having a binder metal,, and a crushed
cast tungsten carbide.
Referring to the macrocrystalline tungsten
carbide, this material is essentially stoichiometric WC
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which is, for the most part, in the form of single
crystals. Some large crystals of macrocrystalline
tungsten carbide are bicrystals. U.S. Patent No.
3,379,503 to McKenna for a PROCESS FOR PREPARING
TUNGSTEN MONOCARBIDE, assigned to the assignee of the
present patent application, discloses a method of
making macrocrystalline tungsten carbide. U.S. Patent
No. 4,834,963 to Terry et al. for MACROCRYSTALLINE
TUNGSTEN MONOCARBIDE POWDER AND PROCESS FOR PRODUCING,
assigned to the assignee of the present patent
application, also discloses a method of making
macrocrystalline tungsten carbide.
Referring to the crushed sintered cemented
macrocrystalline tungsten carbide, this material
comprises small particles of tungsten carbide bonded
together in a metal matrix. For this material as used
in this patent application, the crushed sintered
cemented macrocrystalline tungsten carbide with a
binder (either cobalt or nickel) is made by mixing
together WC particles, Co or Ni powder and a lubricant.
This mixture is pelletized, sintered, cooled, and then
crushed. The pelletization does not use pressure, but
instead, during the mixing of the WC particles and
cobalt, the blades of the mixer cause the mixture of WC
and cobalt (or nickel) to ball up into pellets.
Referring to crushed cast tungsten carbide,
tungsten forms two carbides; namely, WC and W2C. There
can be a continuous range of compositions therebetween.
An eutectic mixture is about 4.5 weight percent carbon.
Cast tungsten carbide commercially used as a matrix
powder typically has a hypoeutectic carbon content of
about 4 weight percent. Cast tungsten carbide is
typically frozen from the molten state and comminuted
to the desired particle size.
In the past, there have been hard composites
comprised of a matrix and discrete hard elements held
therein. In the typical case, the matrix comprised
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carbide-based particulates bonded together by an
infiltrant metal and the hard elements comprised
diamond-based material.
Referring to the carbide-based particulates,
one example of the carbide-based component contains
about 67.10 weight percent macrocrystalline tungsten
carbide having the following size distribution: between
18.0 and 22.0 weight percent of the macrocrystalline
tungsten carbide particles have a size of -80 +120 mesh
(the mesh size is made according to ASTM Standard E-11-
70, and corresponds to greater than 125 micrometers and
less than or equal to 177 micrometers), between 25.0
to 30.0 weight percent of the macrocrystalline tungsten
carbide particles have a size of -120 +170 mesh
(greater than 88 micrometers and less than or equal to
125 micrometers), between 29.0 weight percent and 33.0
weight percent of the macrocrystalline tungsten carbide
particles have a size of -170 +230 mesh (greater than
63 micrometers and less than or equal to 88
micrometers), between 18.0 weight percent and 22.0
weight percent of the macrocrystalline tungsten carbide
particles have a size of -230 +325 mesh (greater than
44 micrometers and less than or equal to 63
micrometers), and up to 5.0 weight percent of the
macrocrystalline tungsten carbide particles have a size
of -325 mesh (less than or equal to 44 micrometers).
The matrix further contains about 30.90 weight percent
crushed cast tungsten carbide particles having a size
of -325 mesh (less than or equal to 44 micrometers),
1.00 weight percent iron that has an average particle
diameter of between 3 micrometers and 5 micrometers,
and 1.00 weight percent grade 4600 steel having a
particle size of -325 mesh (less than or equal to 44
micrometers).
The 4600 grade steel has the following
nominal composition (weight-percent): -1-.57 weight
percent nickel; 0.38 weight percent manganese; 0.32
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weight percent silicon; 0.29 weight percent molybdenum;
0.06 weight percent carbon; and balance iron.
Another example of the carbide-based
component comprises about 65 weight percent of
macrocrystalline tungsten carbide having a particle
size of -80 +325 mesh (greater than 44 micrometers and
less than or equal to 177 micrometers), 27.6 weight
percent tungsten carbide rod milled to an average
particle size of 4 to 6 micrometers with superfines
removed, 2.8 weight percent tungsten having a particle
size of -325 mesh (less than or equal to 44
micrometers), 2.8 weight percent 4600 grade steel
having a particle size of -140 mesh (less than or equal
to 105 micrometers), and 1.8 weight percent of iron
having a particle size of -325 mesh (less than or equal
to 44 micrometers).
Another example of a carbide-based
particulate component comprises 68 weight percent
macrocrystalline tungsten carbide having a size of -80
+325 mesh (greater than 44 micrometers and less than or
equal to 177 micrometers); 15 weight percent of
macrocrystalline tungsten carbide having a size of -325
mesh (less than or equal to 44 micrometers); 15 weight
percent of crushed cast tungsten carbide having a size
of -325 mesh (less than or equal to 44 micrometers);
and 2 weight percent nickel having a size of -325 mesh
(less than or equal to 44 micrometers). This nickel is
INCO type 123 from International Nickel Company and is
a singular spike covered regular shaped powder. The
chemical analysis and physical characteristics
available from commercial literature reveal the
following: The chemical analysis shows a composition
of: 0.1 max. carbon, 0.15 max. oxygen, 0.001 max.
sulfur, 0.01 max. iron, and balance nickel. The average
particle size is 3-7 micrometers (Fisher Subsieve
Size), the apparent density is 1.8-2.7 grams/cc, and
the specific surface area is 0.34-0.44 m2/g.
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Another example of a carbide-based
particulate component comprises 64 weight percent
macrocrystalline tungsten carbide having a size of -80
+325 mesh (greater than 44 micrometers and less than or
equal to 177 micrometers); 14 weight percent of
macrocrystalline tungsten carbide having a size of -325
mesh (less than or equal to 44 micrometers); 14 weight
percent of crushed cast tungsten carbide having a size
of -325 mesh (less than or equal to 44 micrometers);
and 8 weight percent nickel having a size of -200 mesh
(less than or equal to 74 micrometers).
Still another example of a particulate
component comprises a 67.0 weight percent crushed cast
tungsten carbide having a particle size distribution as
follows: between 18.0 and 22.0 weight percent of the
crushed cast tungsten carbide particles have a size of
-80 +120 mesh (greater than 125 micrometers and less
than or equal to 177 micrometers), between 25.0 to
30.0 weight percent of the crushed cast tungsten
carbide particles have a size of -120 +170 mesh
(greater than 88 micrometers and less than or equal to
125 micrometers), between 29.0 weight percent and 33.0
weight percent of the crushed cast tungsten carbide
particles have a size of -170 +230 mesh (greater than
63 micrometers and less than or equal to 88
micrometers), between 18.0 weight percent and 22.0
weight percent of the crushed cast tungsten carbide
particles have a size of -230 +325 mesh (greater than
44 micrometers and less than or equal to 63
micrometers), and up to 5.0 weight percent of the
crushed cast tungsten carbide particles have a size of
-325 mesh (less than or equal to 44 micrometers). The
component further has 31.0 weight percent crushed cast
tungsten carbide having a particle size of -325 mesh
(less than or equal to 44 micrometers), 1.0 weight
percent iron having a particle. size of -325 mesh (less
than or equal to 44 micrometers), and 1.0 weight
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percent 4600 steel having a particle size of -325 mesh
(less than or equal to 44 micrometers).
One example of a suitable infiltrant
comprises 63-67 weight percent copper, 14-16 weight
percent nickel, and 19-21 weight percent zinc. This
material has a specific gravity of 8.5 g/cc and has a
... melting point of 1100 °F. This infiltrant is used in
1/32nd inch by 5/l6ths inch granules. This alloy is
identified as MACROFIL*65 by applicants' assignee, and
this designation will be used in this application.
Another example of a suitable infiltrant has
a nominal composition of 52.7 weight percent copper,
24.0 weight percent manganese, 15.0 weight percent
nickel, 8.0 weight percent zinc, .15 weight percent
boron, and .15 weight percent silicon with traces of
lead, tin and iron. This infiltrant is sold by Belmont
Metals Inc., 330 Belmont Avenue, Brooklyn, New York
11207 under the name designation "VIRGIN binder 4537D"*
in 1 inch by 1/2 inch by 1/2 inch chunks. This alloy is
identified as MACROFIL*53 by applicants' assignee, and
this designation will be used in this application.
While these earlier matrices for a hard
composite have performed in a satisfactory fashion, it
would be desirable to provide an improved matrix for a
hard composite having improved properties. These
properties include impact strength, transverse rupture
strength, hardness, abrasion resistance, and erosion
resistance. It would also be desirable to provide an
improved hard composite that uses~the improved matrix
material. It would still further be desirable to
provide a tool member that includes a tool shank with
the improved hard composite affixed thereto wherein the
tool member could be used, for example, in conjunction
with an oil well drill bit.
*Trade-mark
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SUN~IARY OF THE INVENTION
It is an object of the invention to provide
an improved matrix powder for a hard composite
comprising one or more discrete hard elements held in a
matrix composed of carbide-based particulates bonded
together by an infiltrant metal wherein the matrix has
improved overall properties. It is contemplated that
the hard composite could be used in cutting and
drilling applications, and that the matrix powder and
infiltrant without the hard element could be used in
wear applications.
It is another object of the invention to
provide an improved hard composite comprising a
plurality of discrete hard elements, such a diamond or
polycrystalline diamond composite elements, held in a
matrix composed of carbide-based particulates bonded
together by an infiltrant metal that has improved
impact strength.
It is still another object of the invention
to provide an improved hard composite comprising a
plurality of discrete hard elements, such as diamond or
polycrystalline diamond composite elements, held in a
matrix composed of carbide-based particulates bonded
together by an infiltrant metal that has improved
transverse rupture strength.
It is an object of the invention to provide
an improved hard composite comprising a plurality of
discrete hard elements, such as diamond or
polycrystalline diamond composite elements, held in a
matrix composed of carbide-based particulates bonded
together by an infiltrant metal that has improved
hardness.
It is another object of the invention to
provide an improved hard composite comprising a
plurality of discrete hard elements, such as diamond or
polycrystalline diamond composite.elements, held in a
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matrix composed of carbide-based particulates bonded
together by an infiltrant metal that has improved
erosion resistance properties.
In one form thereof, the invention is a
matrix powder for formation along with an infiltrant
into a matrix. The matrix powder comprises crushed
sintered cemented tungsten carbide particles having a
particle size of -80+400 mesh (greater than 37
micrometers and less than or equal to 177 micrometers).
The composition of the crushed sintered cemented
tungsten carbide comprises between about 5 weight
percent and about 20 weight percent binder metal and
between about 80 weight percent and about 95 weight
percent tungsten carbide.
In still another form thereof, the invention
is a diamond composite member which includes a support
and a diamond composite affixed to the support. The
diamond composite comprises a matrix which includes a
mass of particles held together by an infiltrant. The
mass of particles is formed by heating a powder mixture
in the presence of an infiltrant. The powder mixture
comprises crushed sintered cemented tungsten carbide
particles having a particle size of -80+400 mesh
(greater than 37 micrometers and less than or equal to
177 micrometers). The composition of the crushed
sintered cemented tungsten carbide comprises between
about 5 weight percent and about 20 weight percent
binder metal and between about 80 weight percent and
about 95 weight percent tungsten carbide.
BRIEF DESCRIPTION OF THE DRAWINGS
The following is a brief description of the
drawings which form a part of this patent application:
FIG. 1 is a schematic view of the assembly
used to make a product comprising a tool shank with one
embodiment.of the discrete diamonds bonded thereto; and
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FIG. 2 is a schematic view of the assembly
used to make a product comprising a tool shank with
another embodiment of the diamond composite bonded
thereto; and
FIG. 3 is a perspective view of a tool drill
bit that incorporates the present invention.
DETAILED DESCRIPTION OF SPECIFIC EMBODIMENTS
Referring to FIG. 1, there is illustrated a
schematic of the assembly used to manufacture a product
using the diamond as part of the present invention. The
typical product is a drill head. As will become
apparent, the drill head has a shank. Cutter elements,
such as the discrete diamonds are bonded to the bit
head with the metal matrix. Although the method by
which the shank is affixed to the drill line may vary,
one common method is to provide threads on the shank so
that the shank threadedly engages a threaded bore in
the drill line. Another way is to weld the shank to the
drill line.
The production assembly includes a carbon,
such as graphite, mold, generally designated as 10,
having a bottom wall 12 and an upstanding wall 14. The
mold 10 defines a volume therein. The assembly further
includes a top member 16 which fits over the opening of
the mold 10. It should be understood that the use of
the top number 16 is optional depending upon the degree
of atmospheric control one desires.
A steel shank 24 is positioned within the
mold before the powder is poured therein. A portion of
the steel shank 24 is within the powder mixture 22 and
another portion of the steel shank 24 is outside of the
mixture 22. Shank 24 has threads 25 at one end thereof,
and grooves 25A at the other end thereof.
Referring to the contents of the mold, there
are a plurality of discrete diamonds 20 positioned at
selected positions within the mold so as to be at
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selected positions on the surface of the finished
product. The matrix powder 22 is a carbide=based powder
which is poured into the mold 10 so as to be adjacent
to the diamonds 20. The composition of the matrix
powder 22 will be set forth hereinafter.
Once the diamonds 20 have been set and the
matrix powder 22 poured into the mold, infiltrant alloy
26 is positioned adjacent to the powder mixture 22 in
the mold 10. Then the top 16 is positioned over the
mold, and the mold is placed into a furnace and heated
to approximately 2200 of (1177 °C) so that the
infiltrant 26 melts and infiltrates the powder mass.
The result is an end product wherein the infiltrant
bonds the powder together, the matrix holds the
diamonds therein, and the composite is bonded to the
steel shank.
Referring to FIG. 2, there is illustrated a
schematic of the assembly used to manufacture a second
type of product using the diamond composites as part of
the present invention. The assembly includes a carbon,
such as graphite, mold, generally designated as 30,
having a bottom wall 32 and an upstanding wall 34. The
mold 30 defines a volume therein. The assembly further
includes a top member 36 which fits over the opening of
the mold 30. It should be understood that the use of
the top member 36 is optional depending upon the degree
of atmospheric control one desires.
A steel shank 42 is positioned within the
mold before the powder mixture is poured therein. A
portion of the steel shank 42 is within the powder
mixture 40 and another portion of the steel shank 42 is
outside of the mixture. The shank 42 has grooves 43 at
the end that is within the powder mixture.
Referring to the contents of the mold 30,
there are a plurality of carbon (graphite) blanks 38
positioned at selected positions within the mold so as
to be at selected positions on the surface of the
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finished product. The matrix powder 40 is a carbide-based
powder which is poured into the mold 30 so as to be adjacent to
the carbon (graphite) blanks 38. The composition of the matrix
powder 40 will be set forth hereinafter.
Once the carbon (graphite) blanks 38 have been set
and the matrix powder 40 poured into the mold 30, Infiltrant
alloy 44 is positioned adjacent to the powder mixture in the
mold. Then the top 36 is positioned over the mold, and the
mold is placed into a furnace and heated to approximately 2200°F
(1177°C) so that the infiltrant melts and infiltrates the powder
mass. The result is an intermediate product wherein the
infiltrant bonds the powder together, also bonding the powder
mass to the steel shank, and the carbon (graphite) blanks
define recesses in the surface of the infiltrated mass.
The carbon (graphite) blanks are removed from bonded
mass and a diamond composite insert, having a shape like that
of the carbon (graphite) blank, is brazed into the recess to
form the end product. Typically the diamond composite drill
head has a layer of discrete diamonds along the side.
Referring to FIG. 3, there is illustrated therein a
portion of a tool, generally designated as 50. The tool 50 has
a forwardly facing surface to which are bonded discrete diamond
elements 52.
Preferably, the infiltrant metal is an alloy
comprising about 50 to 70 weight percent copper, about 10 to 20
weight percent nickel and about 15 to 25 weight percent zinc or
an alloy comprising about 45 to 60 weight percent copper, 10 to
20 weight percent nickel, about 4 to 12 weight percent zinc,
about 18 to 30 weight percent manganese, an amount of boron and
an amount of silicon.
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COMPARATIVE EXAMPLES
The following comparative examples were made and
tested and the test results are presented below.
Comparative Example A comprises a powder matrix
mixture having a composition and size distribution as follows:
about 67.10 weight percent macrocrystalline tungsten carbide
having the following size distribution: between 18.0 and 22.0
weight percent of the macrocrystalline tungsten carbide
particles have
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a size of -80 +120 mesh (greater than 125 micrometers
~ and less than or equal to 177 micrometers) between
25.0 to 30.0 weight percent of the macrocrystalline
.. tungsten carbide particles have a size of -120 +170
mesh (greater than 88 micrometers and less than or .
equal to 125 micrometers), between 29.0 weight percent
..-. and 33.0 weight percent of the macrocrystalline
tungsten carbide particles have a size of -170 +230
mesh (greater than 63 micrometers and less than or
equal to 88 micrometers), between 18.0 weight percent
and 22.0 weight percent of the macrocrystalline
tungsten carbide particles have a size of -230 +325
mesh (greater than 44 micrometers and less than or
equal to 63 micrometers), and up to 5.o weight percent
of the macrocrystalline tungsten carbide particles have
a size of -325 mesh (less than or equal to 44
micrometers). The matrix further contains about 30.9
weight percent crushed cast tungsten carbide particles
having a size of -325 mesh (less than or equal to 44
micrometers), 1.00 weight percent iron and has an
average particle diameter of between 3 micrometers and
5 micrometers, and 1.00 weight percent grade 4600 steel
having a particle size of -325 mesh (less than or equal
to 44 micrometers). The 4600 grade steel has the
following nominal composition (weight percent): 1.57
weight percent nickel: 0.38 weight percent manganese:
0.32 weight percent silicon: 0.29 weight percent
molybdenum; 0.06 weight percent carbon: and balance
iron.
TM
The infiltrant was MACROFIL 53. The
TM
composition of the MACROFIL 53 is set forth above. This
TM
powder mixture was placed in a mold along with MACROFIL
53 infiltrant, and heated at about 2200 of (1177 °C)
until the infiltrant had adequately infiltrated the
powder mass so as to bond it together. The mass was
then allowed to cool. -
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Comparative Example B comprises a powder
matrix mixture having a composition and size
distribution as follows: about 68 weight percent
macrocrystalline tungsten carbide having a size of -80
+325 mesh (greater than 44 mic=ometers and less than or
equal to 177 micrometers); 15 weight percent of
macrocrystalline tungsten carbide having a size of -325
mesh (less than or equal to 44 micrometers); 15 weight
.percent of crushed cast tungsten carbide having a size
of -325 mesh (less than or equal to 44 micrometers);
and 2 weight percent nickel having a size of -325 mesh
(less than or equal to 44 micrometers). This nickel is
INCO type 123 from International Nickel Company and is
a singular spike covered regular shaped powder. The
chemical analysis and physical characteristics
available from commercial literature reveal the
following: The chemical analysis shows a composition
of: 0.1 max. carbon, 0.15 max. oxygen, 0.001 max.
sulfur, 0.01 max. iron, and balance nickel. The average
particle size is 3-7 micrometers (Fisher Subsieve
Size), the apparent density is 1.8-2.7 grams/cc, and
the specific surface area is 0.34-0.44 m2/g.
The infiltrant was MACROFILM53. The
TM
composition of the MACROFIL 53 is set forth above. This
powder mixture was placed in a mold along with MACROFILTM
53 infiltrant, and heated at about 2200 of (1177 °C)
until the infiltrant had adequately infiltrated the
powder mass so as to bond it together. The mass was
then allowed to cool.
Comparative Example C comprises a powder
matrix mixture having a composition and size
distribution as follows: about 67.0 weight percent
crushed cast tungsten carbide having a particle size
distribution as follows: between 18.0 and 22.0 weight
percent of the crushed cast tungsten carbide particles
have a size of -80 +120 mesh (greater than 125
microiueters and less than or equal to 177
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micrometers), between 25.0 to 30.0 weight percent of
the crushed cast tungsten carbide particles have a size
of -120 +170 mesh (greater than 88 micrometers and less
than or equal to 125 micrometers), between 29.0 weight
- percent and 33.0 weight percent of the crushed cast
-tungsten carbide particles have a size of -170 +230
'mesh (greater than 63 micrometers and less than or
equal to 88 micrometers), between 18.0 weight percent
and 22.0 weight percent of the crushed cast tungsten
carbide particles have a size of -230 +325 mesh
(greater than 44 micrometers and less than or equal to
63 micrometers), and up to 5.0 weight percent of the
crushed cast tungsten carbide particles have a size of
-325 mesh (less than or equal to 44 micrometers). The
component further has 31.0 weight percent crushed cast
tungsten carbide having a particle size of -325 mesh
(less than or equal to 44 micrometers), 1.0 weight
percent iron having a particle size of -325 mesh (less
than or equal to 44 micrometers), and 1.0 weight
percent 4600 steel having a particle size of -325 mesh
(less than or equal to 44 micrometers).
TM '
The infiltrant was'MACROFIL 53. The
TM
composition of the MACROFIL 53 is set forth above. This
powder mixture was placed in a mold along with MACROFILTM
53 infiltrant, and heated at about 2200 of (1177 °C)
until the infiltrant had adequately infiltrated the
powder mass so as to bond it together. The mass was
then allowed to cool.
Comparative Example D comprises a powder
matrix mixture having a composition and size
distribution as follows: about 64 weight percent
macrocrystalline tungsten carbide having a size of -80
+325 mesh (greater than 44 micrometers and less than or
equal to 177 micrometers); 14 weight percent of
macrocrystalline tungsten carbide having a size of -325
mesh (less than or equal to 44 micrometers); 14 weight
percent of crushed cast tungsten carbide having a size
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of -325 mesh (less than or equal to 44 micrometers);
and 8 weight percent nickel. having a size of -200 mesh
(less than or equal to 74 micrometers). This nickel is
INCO type 123 from International Nickel Company and is
a singular spike covered regular shaped powder. The
chemical analysis and physical characteristics
available from commercial literature reveal the
following: The~chemical analysis shows a composition
of: 0.1 max. carbon, 0.15 max. oxygen, 0.001 max.
sulfur, 0.01 max. iron, and balance nickel. The average
particle size is 3-7 micrometers (Fisher Subsieve
Size), the apparent density is 1.8-2.7 grams/cc, and
the specific surface area is 0.34-0.44 m2/g.
The infiltrant was MACROFILM53. The
composition of the MACROFIL 53 is set forth above. This
powder mixture was placed in a mold along with MACROFILTM
53 infiltrant, and heated at about 2200 °F (1177 °C)
until the infiltrant had adequately infiltrated the
powder mass so as to bond it together. The mass was
then allowed to cool.
Actual Examples
The following actual examples of the present
invention have been made and tested and the test
results are also set forth below.
Examble No. 1
Example No. 1 comprises a powder matrix
mixture having a composition and size distribution as
follows: 100 weight percent of crushed sintered
cemented macrocrystalline tungsten carbide particles
having a particle size of -140 +325 mesh (greater than
44 micrometers and less than or equal to 105
micrometers). The composition of the cemented
macrocrystalline tungsten carbide comprises 13 weight
percent cobalt and 87 weight percent macrocrystalline
tungsten carbide wherein the macrocrystalline tungsten
carbide has an average particle size between about 5
micrometers and about 25 micrometers.
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TM
The infiltrant was MACROFIL 53. The
TM
composition of the MACROFIL 53 is set forth above. This
powder mixture was placed in a mold along with MACROFILTM
_53 infiltrant, and heated at about 2200 of (1177 °C)
_~until the infiltrant had adequately infiltrated the
powder mass so as to bond it together. The mass was
then allowed to cool.
example No. 2
r Example No. 2 comprises a powder mixture
comprising the following: 100 weight percent of crushed
- sintered cemented macrocrystalline tungsten carbide
particles having a particle size of -140+270 mesh
(greater than 63 micrometers and less than or equal to
105 micrometers). The composition of the cemented
macrocrystalline tungsten carbide comprises 6 weight
percent cobalt and 94 weight percent macrocrystalline
tungsten carbide wherein the tungsten carbide has an
average particle size between about 5 micrometers and
about 25 micrometers.
TM
The infiltrant was MACROFIL 53. The
TM
. composition of the MACROFIL 53 is set forth above. This
TM
powder mixture was placed in a mold along with MACROFIL
53 infiltrant, and heated at about 2200 of (1177 °C)
until the infiltrant had adequately infiltrated the
powder mass so as to bond it together. The mass was
then allowed to cool.
Examgle No. 3
Example No. 3 comprises a powder mixture that
has the following composition and particle size
distribution:
(a) about 50.25 weight percent of the
mixture is macrocrystalline tungsten carbide particles
with a particle size of -80+325 mesh (greater than 44
micrometers and less than or equal to 177 micrometers);
and
(b) about 25.00 weight percent of the mixture
is crushed sintered cemented macrocrystalline tungsten
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. carbide particles of a size of -120 mesh (less than or
_ equal to 125 micrometers), and has the following
composition: about 6 weight percent cobalt, a maximum
of 1 weight percent iron, a maximum of l.0 weight
percent tantalum, a maximum of 1.0 weight percent
titanium, a maximum of 0.5 weight percent niobium, a
,maximum of 0.5 weight percent of other impurities and
the balance macrocrystalline tungsten carbide having an
average particle size of between about 5 micrometers
and about 25 micrometers; and
(c) about 23.25 weight percent of the mixture
is cast tungsten carbide having a particle size of -270
mesh (less than or egual to 53 micrometers) with
superfines removed;
(d) about 0.75 weight percent of the mixture
is grade 4600 steel having particle size of -325 mesh
(less than or equal to 44 micrometers); and
(e) about 0.75 weight percent of the mixture
is iron having an average particle size of 3-5
micrometers.
This powder mixture was placed in a mold
TM
along with the MACROFIL 53 infiltrant, and heated at
about 2200 of (1177 °C) until the infiltrant adequately
infiltrated the powder mass so as to bond it together..
The mass was then allowed to cool.
Examgle No. 4
Example No. 4 comprises a powder mixture that
has the following composition and particle size
distribution:
(a) about 33.50 weight percent of the
mixture is macrocrystalline tungsten carbide particles
with a particle size of -80+325 mesh (greater than 44
micrometers and less than or equal to 177 micrometers);
(b) about 50.00 weight percent of the mixture
is crushed sintered cemented macrocrystalline tungsten
carbide particles of a size of -120 mesh (less than or
equal to 125 micrometers), and having the following
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composition: about 6 weight percent cobalt, a maximum
of 1 weight percent iron, a maximum of 1.0 weight
percent tantalum, a maximum of 1.0 weight percent
titanium, a maximum of 0.5 weight percent niobium, a
maximum of 0.5 weight percent of other impurities and
-the balance macrocrystalline tungsten carbide having an
' average particle size of between about 5 micrometers to
about 25 micrometers;
(c) about 15.50 weight percent of the mixture
is cast tungsten carbide having a particle size of -270
mesh (less than or equal to 53 micrometers) with the
superfines removed:
(d) about 0.50 weight percent of the mixture
is grade 4600 steel having a particle size of -325 mesh
(less than or equal to 44 micrometers); and
(e)about 0.50 weight percent of the mixture
is iron having an average particle size of 3-5
micrometers.
This powder mixture was placed in a mold
TM
along with a MACROFIL 53 infiltrant, and was heated at
about 2200 of (1177 oC) until the infiltrant adequately
infiltrated the powder mass so as to bond it together.
The mass was then allowed to cool.
Examgl a No . 5
Example No. 5 comprises a powder mixture
having the following composition and particle size
distribution:
(a) about 16.75 weight percent of the
mixture is macrocrystalline tungsten carbide particles
with a particle size of -80+325 mesh (greater than 44
micrometers and less than or equal to 177 micrometers);
(b) about 75.00 weight percent of the mixture
is crushed sintered cemented macrocrystalline tungsten
carbide particles of a particle size of -120 mesh (less
than or equal to 125 micrometers), and, having the
following composition: about 6 weight percent cobalt,
a maximum of 1 weight percent iron, a maximum of 1.0
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weight percent tantalum, a maximum of 1.0 weight
percent titanium, a maximum of 0.5 weight percent
niobium, a maximum of 0.5 weight percent of other
impurities and the balance macrocrystalline tungsten
carbide having an average particle size between about 5
micrometers and about 25 micrometers;
(c) about 7.75 weight percent of the mixture
is cast tungsten carbide having a particle size of -270
mesh (less than or equal to 53 micrometers) with
superfines removed:
(d) about 0.25 weight percent of the mixture
is grade 4600 steel with a particle size of -325 mesh
(less than or equal to 44 micrometers), and
(e) about 0.25 weight percent of the mixture
is iron, having an average particle size of 3-5
micrometers.
This powder mixture was placed in a mold
TM
along with a MACROFIL 53 infiltrant, and heated at
about 2200 of (1177 °C) until the infiltrant adequately
infiltrated the powder mass so. as to bond it together.
The mass was then allowed to cool.
Example No. 6
Example No. 6 comprises a powder mixture
having the following composition and particle size
distribution:
(a) about 100 weight percent of the mixture
is crushed sintered cemented macrocrystalline tungsten
carbide particles with a particle size of -120 mesh
(less than or equal to 125 micrometers) and having the
following composition: about 6 weight percent cobalt,
a maximum of 1 weight percent iron, a maximum of 1.0
weight percent tantalum, a maximum of 1.0 weight
percent titanium, a maximum of 0.5 weight percent
niobium, a maximum of 0.5 weight percent of other
impurities and the balance macrocrystalline tungsten
carbide having an average particle size of between
about 5 micrometers and about 25 micrometers.
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This powder mixture was placed in a mold
TM
along with a MACROFIL 53 infiltrant, and was heated at
about 1177°C (2200 °F) until the infiltrant had
adequately infiltrated the powder mass so as to bond it
together. The mass was then allowed to cool.
ample No. 7
Example No. 7 comprises a powder mixture of
100 weight percent cemented macrocrystalline tungsten
carbide having a composition of 10 weight percent
nickel and 90 weight percent macrocrystalline tungsten
carbide. The particle size distribution of the powder
mixture comprises: 0.1 weight percent of the cemented
macrocrystalline tungsten carbide having a particle
size of -80+120 mesh (greater than 125 micrometers and
less than or equal to 177 micrometers); 11.4 weight
percent of the cemented macrocrystalline tungsten
carbide having a particle size of -120+170 mesh
(greater than 88 micrometers and less than or equal to
125 micrometers): 41.1 weight percent of the cemented
macrocrystalline tungsten carbide having a particle
size of -170+230 mesh (greater than 63 micrometers and
less than or equal to 88 micrometers); 44.5 weight
percent of the cemented macrocrystalline tungsten
carbide having a particle size of -230+325 mesh
(greater than 44 micrometers and less than or equal to
63 micrometers); and 2.9 weight percent of the cemented
macrocrystalline tungsten carbide having a particle
size of -325+400 mesh (greater than 37 micrometers and
less than or equal to 44 micrometers).
This powderTmixture was placed in a mold
along with a MACROFIL 53 infiltrant, and was heated at
about 1177°C (2200 °F) until the infiltrant had
adequately infiltrated the powder mass so as to bond it
together. The mass was then allowed to cool.
Example Nos. 8 and 9
Examples Nos. 8 and 9 are the same as Example
No. 7.
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To form the cemented macrocrystalline
tungsten carbide for Examples Nos. 7 through 9,
macrocrystalline tungsten carbide was mixed with 10
weight percent nickel and the powder mixture sintered
for one hour at 1371 °C (2500°F). The sintered material
was then crushed into the particle sizes set forth in
Examples Nos. 7 through 9.
Test Results
Tests for impact strength were conducted
according to a procedure using an impact toughness
machine. The machine had a hammer which when dropped
created an impact loading force on a test specimen. The
load required to break the specimen and the time it
took to break the specimen were used to calculate the
impact strength. This test was conducted using a
Dynatap instrumented drop weight tower. This test is a
high strain rate three-point bend test which measures
the amount of energy required to break a one-half inch
diameter sample pin.
Tests for the transverse rupture strength
were conducted according to a procedure where a
cylindrical pin of the infiltrated material was placed
in a fixture. A load was then exerted on the pin until
failure. The transverse rupture strength was then
calculated based upon the actual load and the
dimensions of the pin specimen. Tests for hardness were
conducted according to the ASTM Standard B347-85
The results of the testing for impact
strength, transverse rupture strength and hardness are
set forth below for the six examples and the three
comparative examples.
Example No. 1
Impact Strength 4.728 ft-lbs
Transverse Rupture Strength 136 ksi
Hardness 29.2 Rockwell C
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Example No. 2.
Impact Strength 6.792 ft-lbs
Transverse Rupture Strength 184 ksi
Hardness 44.8 Rockwell C
Example No. 3
Impact Strength 3.516 ft-lbs
Transverse Rupture Strength 105 ksi
Hardness 33.6 Rockwell C
Example No. 4.
Impact Strength 4.819 ft-lbs
Transverse Rupture Strength 131 ksi
Hardness 42.2 Rockwell C
Example No. 5
Impact Strength 5.222 ft-lbs
Transverse Rupture Strength 153 ksi
Hardness 44.3 Rockwell C
Example No. 6
Impact Strength 8.356 ft-lbs
Transverse Rupture Strength 162 ksi
Hardness 42.5 Rockwell C
Example No. 7
Impact Strength 9.249 ft-lbs
Transverse Rupture Strength 216 ksi
Hardness 41.7 Rockwell C
Example No. 8
Impact Strength 7.912 ft-lbs
Transverse Rupture Strength 202 ksi
Hardness 35.4 Rockwell C
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Example No. 9
Impact Strength 7.421 ft-lbs
Transverse Rupture Strength 191 ksi
Hardness 36.3 Rockwell C
Example A.
Impact Strength 2.730 ft-lbs
Transverse Rupture Strength 116 ksi
Hardness 38.3 Rockwell C
Example B
Impact Strength 3.094 ft-lbs
Transverse Rupture Strength 114 ksi
Hardness 31.5 Rockwell C
Example C
Impact Strength 2.466 ft-lbs
Transverse Rupture Strength 96 ksi
Hardness 38.7 Rockwell C
Example D
Impact Strength -- ft-lbs
Transverse Rupture Strength 128 ksi
Hardness -- Rockwell C
The abrasion testing was done according to
the Riley - Stoker method (ASTM Standard B611) using a
counterbalance weight of 26 Kg. These results are set
forth below:
Weight Loss
Samble (Top/Bottom)*
Example No. 1 426.5/373.9
Example No. 2 373.3/298.2
Example No. 3 427.6/423.5
Example No. 4 394.4/387.4
Example No. 5 382.7/375.1
Example No. 6 339.8/374.0
Example No. 7 -- 344.8/ -
Example No. 8 _ 350.4/257.2
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Example No. 9 357.4/331.7
Example A 439.9/443.5
Example B 472.1/466.4
Example C 322.3/329.0
Example D 419.4/406.5
* of a coin
The units for the weight loss are grams per
fifty wheel revolutions.
For the erosion test procedure, the testing
consisted of subjecting coins made of the matrix
material to a high pressure water plus sand abrasive
stream for a set length of time and measuring the mass
loss of the coin. The test parameters were set as
follows:
Water Pressure........1000psi
Sand Grit Size........ASTM 50-70(fine)
Nozzle Size...........#4-15 degree
Test Duration.........1 minute
Impingement Angle.....20 degrees
The test setup consisted of a large, high
pressure water pump unit, a barrel of sand, a trigger-
operated nozzle delivery system, and the hoses to
connect all of these together. The procedure used for
testing was to weigh the coin, place it into the blast
fixture, blast it for one minute, then weight it again
to measure the loss due to erosion. The scale used to
weigh the coin was a Mettler balance with a resolution
of 0.002 grams. The coin was cleaned and dried prior to
every weighing. Two tests were done on each side of the
coin.
The sand and water flow rates were also
monitored. The water flow rate averaged at about 2
gallons per minute throughout the entire test. The sand
flow rate averaged about 0.65 lbs./minute for the test
with some noticeable increase as the testing
progressed. The accuracy of the sand flow measurement
was about ~0.05 lbs/minute. This test procedure follows
ASTM Standard G76, except that it uses a liquid jet
instead of a gas jet.
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These test results
have been normalized
to
take into account the variations in sand flow. The
weight loss is in grams.
Weight Loss
Sample (Top/Bottom)*
Example No. 1 0.25/0.19
Example No. 2 0.16/0.13
Example No. 3 0.12/0.16
Example No. 4 0.13/0.10
Example No. 5 0.11/0.13
Example No. 6 0.10/0.08
Example No. 7 -----
Example No. 8 0.05/0.04
Example No. 9 -----
Example A 0.42/0.37
Example B 0.38/0.37
Example C 0.17/0.17
Example D 0.12/0.09
* of a coin
Other embodiments
of the invention
will be
apparent to those skilled in the art from a
consideration of the
specification or
practice of the
invention disclosed intended that the
herein. It is
specification and examples be sidered as
con
illustrative only, with the true scope and spirit of
the invention being the following claims
indicated by
