AU2022249075B2 - Copper-based alloy and metal matrix composite formed using same - Google Patents

Abstract

The disclosure relates generally to copper-based alloys, and more particularly to copper-based alloys adapted for forming metal matrix composite (MMC) materials, and to methods of making the MMC materials. In one aspect, an alloy for forming a matrix of an MMC material has an elemental composition including: manganese (Mn) at 5.6-10.4 weight percent (wt. %); nickel (Ni) at 3.5-6.5 wt. %; tin (Sn) at 1.4-4 wt. %; and copper (Cu) exceeding 55 wt. % and up to a balance of the elemental composition. The alloy has a solidus temperature lower than a melting temperature of Cu.

Description

2022249075 25 Sep 2024

COPPER-BASED ALLOYAND COPPER-BASED ALLOY ANDMETAL METAL MATRIX MATRIX COMPOSITE COMPOSITE FORMED FORMED USING USING SAME SAME CROSS-REFERENCE CROSS-REFERENCE TO TORELATED RELATEDAPPLICATION APPLICATION

[0001] This application

[0001] This application claims claims the the benefit benefit of of priority priority to to U.S. U.S.Provisional Provisional 2022249075

application applicationnumber number 63/169669, 63/169669, filed filed April April1,1,2021, 2021,entitled entitled"COPPER-BASED ALLOY "COPPER-BASED ALLOY

AND METAL AND METAL MATRIX MATRIX COMPOSITE COMPOSITE FORMEDFORMED USING USING SAME," SAME," the the of content content whichof is which is incorporated incorporated by by reference reference herein herein inentirety. in its its entirety.

BACKGROUND BACKGROUND Field Field

[0002] The disclosure

[0002] The disclosure relates relates generally generally to tungsten to tungsten carbide carbide particles, particles, andand more more

particularly tototextured particularly texturedspheroidal spheroidaltungsten tungstencarbides, carbides,composites composites formed thereof, and formed thereof, and

methods ofapplying methods of applyingthe thecomposites. composites.

[0002a] Any discussion

[0002a] Any discussion of theofprior the prior art throughout art throughout the specification the specification should should in no in no

waybebeconsidered way consideredasasananadmission admissionthat thatsuch suchprior priorart art is is widely widely known known ororforms formspart partofof common common general general knowledge knowledge in the in the field. field.

[0002b]

[0002b] It isIt an is an object object of of thethe presentinvention present invention toto overcome overcome or ameliorate or ameliorate at at least least

one ofthe one of thedisadvantages disadvantages of prior of the the prior art, art, or toorprovide to provide a useful a useful alternative. alternative.

[0002c] Unless

[0002c] Unless the context the context clearly clearly requires requires otherwise, otherwise, throughout throughout the description the description

and the claims, and the claims, the the words “comprise”,"comprising", words "comprise", “comprising”,and and thelike the likeare areto to be be construed construedin in an an inclusive senseasasopposed inclusive sense opposed to antoexclusive an exclusive or exhaustive or exhaustive sense; sense; that that is to isintothe say, say,sense in the of sense of

“including, butnotnot "including, but limited limited to”. to".

Description Description ofofthe theRelated RelatedArtArt

[0003] A metal

[0003] A metal matrix matrix composite composite (MMC) (MMC) refers refers to to a composite a composite material material which which

includes particles includes particles that thatare areembedded withinaametallic embedded within metallic matrix. matrix. AAMMC MMC generally generally includes includes a a high-meltingtemperature high-melting temperaturemetallic metallic powder powder that that is infiltrated is infiltrated with with a single a single metal metal or or more more commonlyananalloy commonly alloyhaving havinga alower lowermelting meltingtemperature temperaturethan thanthe thepowder. powder.MMCs MMCs have have

various applications, including various applications, including mining equipment.The mining equipment. The physical physical properties properties of of MMCs MMCs can be can be

engineered through engineered component materials through component materials and andmanufacturing manufacturing processes processes thereof. thereof.

-1-

SUMMARY SUMMARY 25 Sep 2024 2022249075 25 Sep 2024

[0003a] According

[0003a] According to a to a first first aspect aspect ofpresent of the the present invention invention there is there is provided provided an alloy an alloy

comprising: comprising:

manganese(Mn) manganese (Mn) at at 5.6-10.4 5.6-10.4 weight weight percent percent (wt. (wt. %);%);

nickel (Ni) at 3.5-6.5 wt. %; nickel (Ni) at 3.5-6.5 wt. %;

tin (Sn) at 1.4-4 wt. %; tin (Sn) at 1.4-4 wt. %;

additional elements additional at aa combined elements at concentrationless combined concentration lessthan than 2%; 2%;and and 2022249075

balance of balance of copper copper (Cu), (Cu) , whereinthe wherein the alloy alloy has has aa solidus solidus temperature lower than temperature lower than aa melting melting temperature temperatureofofCu. Cu.

[0003b] According

[0003b] According to to a second a second aspect aspect of the of the present present invention invention therethere is provided is provided a a metal matrix metal matrixcomposite compositematerial materialcomprising comprising reinforcement reinforcement particles particles embedded embedded in a copper- in a copper-

based matrix, based matrix, wherein whereinthe thecopper-based copper-basedmatrix matrix comprises comprises

1.4-4 wt.%%tintin(Sn); 1.4-4 wt. (Sn); 5.6-10.4 5.6-10.4 wt. wt. % manganese % manganese (Mn); (Mn);

3.5-6.5 wt.% % 3.5-6.5 wt. nickel nickel (Ni); (Ni);

additional elements additional at aa combined elements at concentrationless combined concentration lessthan than 2%; 2%;and and aa balance of copper balance of copper (Cu), (Cu), wherein whereinthe thecopper-based copper-based matrix matrix hashas a solidus a solidus temperature temperature

lower than aa melting lower than melting temperature temperatureofofCu. Cu .

[0004] Inone

[0004] In oneaspect, aspect,an an alloy alloy is described. is described. In some In some aspects, aspects, an includes: an alloy alloy includes: manganese(Mn) manganese (Mn) at 5.6-10.4 at 5.6-10.4 weight weight percent percent (wt.%); (wt.%); nickel nickel (Ni) (Ni) at 3.5-6.5 at 3.5-6.5 wt.%; wt.%; tin (Sn) tin (Sn) at at 1.4-4 1.4-4 wt. wt. %; and copper %; and copper(Cu) (Cu)exceeding exceeding 55 55 wt.wt. % and % and upa to up to a balance balance of alloy, of the the alloy, wherein wherein

the alloy the alloy has has aa solidus solidus temperature temperature lower lower than than aa melting melting temperature temperature of of Cu. Cu. In In some some

embodiments, thealloy embodiments, the alloyhas hasa asolidus solidus temperature temperatureisis lower lowerthan than1300 1300K.K.

[0005] In some

[0005] In some embodiments, embodiments, the alloy the alloy forms forms a single a single phase phase solid solution solid solution havinghaving

aa face-centered face-centered cubic cubic (FCC) crystal structure (FCC) crystal structure from from aa solidus solidus temperature downtotoatat least temperature down least 400 400

- 1a - la--

K below the solidus temperature. In some embodiments, greater than 90 wt.% of the alloy is

a single phase solid solution with a face-centered cubic (FCC) crystal structure at room

temperature. In some embodiments, the alloy further includes up to 2 wt. % of impurities. In

some embodiments, the elemental composition does not include one or more of Si, B and Zn.

[0006] In some aspects, the techniques described herein relate to an alloy,

wherein the alloy has an electrical conductivity higher than 2.5 MS/m. In some

embodiments, the alloy has a thermal conductivity higher than 10 W/mK.

[0007] In some embodiments, the alloy forms a matrix of a metal matrix

composite (MMC) material, wherein the MMC material further includes tungsten carbide

particles. In some embodiments, the alloy forms a matrix of a metal matrix composite

(MMC) material, wherein the MMC material forms part of a drilling component. In some

embodiments, the alloy forms a matrix of a metal matrix composite (MMC) material,

wherein the MMC material has a toughness greater than 4,000 in*lbf/in³

[0008] In some aspects, the techniques described herein relate to an alloy,

wherein the alloy is part of a feedstock for forming a metal matrix composite (MMC)

material, wherein the feedstock further includes tungsten carbide particles.

[0009] Another aspect describes a metal matrix composite material including

reinforcement particles embedded in a copper-based matrix, wherein the copper-based matrix

includes greater than 55 wt. % copper (Cu) and greater than 1.4 wt. % tin (Sn).

[0010] In some embodiments, the copper-based matrix includes: 1.4-2.6 wt. % tin

(Sn); 5.6-10.4 wt. % manganese (Mn); and 3.5-6.5 wt. % nickel (Ni), wherein the copper-

based matrix has a solidus temperature lower than Cu. In some embodiments, the solidus

temperature of the copper-based matrix is lower than 1300 K.

[0011] In some embodiments, the copper-based matrix forms a single phase solid

solution having a face-centered cubic (FCC) crystal structure from a solidus temperature

down to at least 400K below the solidus temperature. In some embodiments, greater than 90

wt.% of the copper-based matrix is a single-phase solid solution having a face-centered cubic

(FCC) crystal structure at room temperature. In some embodiments, the copper-based matrix

includes 2 wt. % or less of impurities.

[0012] In some embodiments, the copper-based matrix does not include one or

more of Si, B and Zn. In some embodiments, the copper-based matrix has an electrical conductivity higher than 2.5 MS/m. In some embodiments, the copper-based matrix has a thermal conductivity higher than 10 W/mK. In some embodiments, the reinforcement particles include tungsten carbide particles. In some embodiments, the tungsten carbide particles include 50-70 vol.% of the metal matrix composite material. In some embodiments, the tungsten carbide particles have an average particle size of 1-200 µm.

[0013] In some embodiments, the tungsten carbide particles have a spheroidal

shape having ratio, between a first length along a major axis and a second length along a

minor axis, of 1.20 or lower. In some embodiments, the tungsten carbide particles have a

surface that is textured to have a grain boundary area fraction greater than 5.0 %. In some

embodiments, the metal matrix composite material has a transverse rupture strength

exceeding 175 ksi. In some embodiments, the metal matrix composite material forms part of

a drilling component.

BRIEF DESCRIPTION OF THE DRAWINGS

[0014] FIG. 1 illustrates a scanning electron microscopy (SEM) image of a prior

art metal powder with angular particles.

[0015] FIG. 2 illustrates an optical micrograph of a prior art metal matrix

composite (MMC) prepared using angular particles.

[0016] FIG. 3 illustrates an optical micrograph of a MMC prepared using

spheroidal or substantially spherical particles.

[0017] FIG. 4 illustrates an apparatus for producing an MMC.

[0018] FIG. 5 illustrates an embodiment of earth-engaging tool with a drill bit.

[0019] FIG. 6 illustrates strength and reliability improvements of some MMC

embodiments

[0020] FIG. 7 illustrates a scanning electron micrograph (SEM) of a conventional

MMC.

[0021] FIGS. 8-9 illustrate scanning electron micrographs of an MMCs according

to embodiments.

[0022] FIG. 10 illustrates a binary image of FIG. 7.

[0023] FIG. 11 illustrates a binary image of FIG. 8.

[0024] FIG. 12 illustrates a binary image of FIG. 9.

[0025] FIG. 13 illustrates an optical micrograph of a MMC comprising tungsten

carbide particles embedded in a Cu-based matrix, according to embodiments.

[0026] FIG. 14 shows example samples prepared for testing MMCs having Cu-

based matrix and tungsten carbide particles, according to embodiments.

[0027] FIG. 15. illustrates experimental results of strength testing of a MMC

comprising tungsten carbide particles embedded in a Cu-based matrix, according to

embodiments.

DETAILED DESCRIPTION

[0028] Disclosed herein are embodiments of spheroidal or substantially spherical

fused tungsten carbide particles and metal matrix composites (MMCs) formed from tungsten

carbide particles. The MMCs can include a matrix comprising copper and/or copper alloys,

along with tungsten carbide particles. In some embodiments, the tungsten carbide particles

and MMCs formed therefrom can have substantially improved properties over conventional

angular fused tungsten carbide particles as well as MMCs formed therefrom. In particular,

embodiments of the disclosure can be used to improve erosion resistance and impact

resistance of resulting metal matrix composites.

[0029] Also disclosed herein are embodiments of a feedstock alloy for forming a

copper-based matrix of a MMC with reinforcement particles. The copper-based matrix, and

the MMC integrating the copper-based matrix may both be reinforced with particles. In

some embodiments, the particles may be spherical tungsten carbide particles. In some

embodiments, the copper-based matrix as well as MMCs formed therefrom can have

substantially improved properties over conventional matrices or MMCs formed therefrom.

In some embodiments, the thermal conductivity of MMCs and components incorporating the

same may be improved.

[0030] Spheroidal or substantially spherical fused tungsten carbide particles can

be made from commercially available fused tungsten carbide powder or a mixture of

tungsten, mono tungsten carbide and/or carbon. In some embodiments, spheroidal or

substantially spherical fused tungsten carbide particles can have a combined carbon

composition from 3.7 to 4.2 (or about 3.7 to 4.2) wt. % carbon (C), with the balance of the

composition being tungsten (W). The fused tungsten carbide particles can be produced by several methods. In some methods, a mixture of tungsten powder blended with mono tungsten carbide and carbon powder is melted. The molten mixture of tungsten powder, mono tungsten carbide and carbon powder is then atomized by a rotation atomizing process or an ultra-high temperature melting & atomizing process. A rotation atomizing process includes spinning or rotating the molten mixture such that centrifugal forces break the liquid and throw off molten metal as a spray of droplets. These droplets may then solidify as powder particles. Atomization processes generally spheroidize molten tungsten carbide into spheroidal or substantially spherical fused tungsten carbide particles during the rapid solidification process due to surface tension of the molten metal.

[0031] Other methods for the production of a spheroidal or substantially spherical

fused tungsten carbide particles may be based on the modification of regular fused tungsten

carbide powder. Plasma spraying, electric induction or electric resistance furnace melting

may be used during the spheroidization process to obtain fine spheroidal or substantially

spherical fused tungsten carbide particles.

[0032] Sphericity can be defined by an aspect ratio of the spheroidal or

substantially spherical particles. The aspect ratio can be a ratio of a first length along a major

axis to a second length along a minor axis of the particles, or a ratio of the longest axis length

to the shortest axis length of the spheroidal or substantially spherical particles. For example,

a perfect spherical particle would have an aspect ratio of exactly one. On the other hand,

angular particles have an aspect ratio of at least 1.30.

[0033] In some embodiments, spherical or substantially spherical fused tungsten

carbide particles can have an aspect ratio of about 1.20, about 1.10, about 1.05, or a

value within any range of these values. In some embodiments the aspect ratio can represent

an average value of aspect ratios of a plurality of fused tungsten carbide particles. In some

embodiments, each of the particles can have an aspect ratio within a range disclosed herein.

[0034] The specific density of the spherical or substantially spherical fused

tungsten carbide powder can be around 16.5 g/cm³ with a micro-hardness as defined by a

Vickers pyramid number (HV) ranging from 2,700-3,300 HV (or about 2,700 - about 3,300

HV) or any value there between. Without being limited by theory, the inventors have found

that these high microhardness values might be attributed to, among other things, the particle

shape and internal microstructure resulting from the spheroidization processes as described herein. In comparison, conventional mostly angular fused tungsten carbide particles exhibit a substantially inferior hardness of about 1,500~2,200 HV. The inventors have discovered that MMCs containing spheroidal or substantially spherical fused tungsten carbide particles are more wear resistant than those that contain a similar size and fraction of angular fused tungsten carbide particles.

[0035] FIG. 1 shows a scanning electron microscope (SEM) image of an angular

metallic powder.

[0036] FIG. 2 illustrates an optical micrograph of a MMC prepared using

metallographic techniques from an angular conventional fused tungsten carbide powder. The

MMC includes a soft phase 202, a particulate phase 204 formed from a powder similar to

that shown in FIG. 1, and a particulate-to-soft phase interface 206. The soft phase 202 can be

formed by a matrix material that is first melted and subsequently cooled. Thus, the

conventional MMC includes two principal phases. The soft phase 202 is formed through the

liquid metal infiltration of the particulate phase 204.

[0037] The particulate phase 204 can include metal carbides, borides or oxides.

For example, the particulate phase 204 can include tungsten carbides including: mono

tungsten carbide, fused tungsten carbide or cemented tungsten carbide. Typically, the

tungsten carbide particles are angular, as shown in FIG. 1. Between the soft phase 202 and

the particulate phase 204 there is an interface 206. The inventors have discovered that all

three phases 202, 204, and 206 can contribute to the strength and wear properties of the

MMC.

[0038] FIG. 3 illustrates an optical micrograph of a metal matrix composite

(MMC) 300 prepared using spheroidal or substantially spherical carbide particles. As shown,

the MMC 300 includes spheroidal or substantially spherical fused tungsten carbide particles

302 and a soft phase 304, which are combined to form the metal matrix composite (MMC)

300. The MMC 300 additionally includes a spheroidal or substantially spherical fused

tungsten carbide-to-soft phase interface 306.

[0039] The interface 306 includes metallic or metallurgical bonds formed

between the tungsten carbide particles 302 and the soft phase 304. It should be appreciated

that the metallurgical bonds disclosed herein may comprise diffused atoms and/or atomic

interactions, and may include chemical bonds formed between atoms of the particles 302 and the atoms of the soft phase 304. A metallurgical bond is more than a mere mechanical bond.

Under such conditions, the component parts may be wetted to and by the metallic binding

material. Wetting is the ability of a liquid to maintain contact with a solid surface resulting

from intermolecular interactions when the liquid and the solid surface are brought together.

[0040] Before being incorporated into the MMC, a powder mixture including the

spheroidal or substantially spherical tungsten carbide particles is formed. The MMC formed

from the spheroidal or substantially spherical may be called spherical MMCs, whereas the

conventional MMCs formed from angular powders may be called angular MMCs.

[0041] In some embodiments, a liquid metal infiltration route can be used to form

MMC. Liquid metal infiltration is a process in which a compacted powder material is

immersed inside a liquid metal (e.g., a binding material) or contacts the liquid metal (e.g., the

binding material). The liquid metal fills the pores in the compacted powder material, a

process that is driven by surface energy of the compacted powder material. For example, a

metallic binding material may, be any suitable brazing metal, including: copper, chromium,

tin, silver, cobalt nickel, cadmium, manganese, zinc and/or cobalt or an alloy thereof. The

metallic binding material can be liquid cast through tungsten carbide powder and solidified to

form a MMC.

[0042] Specifically, liquid metal infiltration of a powder containing the

components is described with reference to FIG. 4. A graphite mold assembly 412, 414 is

produced that reflects a negative of the desired shape of a drill bit 500. A powder 408

comprising the spheroidal or substantially spherical particles is poured and compacted in the

mold assembly 412, 414. Subsequently, a binder 406, e.g., copper or copper alloy, and steel

parts 404 may be added. Configured mold assembly 412, 414 is heated to melt at least the

binder 406. Within the mold 412, 414 is a sand component 402 which defines regions within

the resulting casting that is free from MMC. Upon melting, the binder 406 infiltrates the

powder 408 and creates bonds to the steel parts 404. Upon cooling, the solidified structure

contains a plurality of composites advantageously located for strength and wear

considerations.

[0043] In some embodiments, the binder may be copper. In some embodiments,

the binder may be a copper-based alloy. In some embodiments, a quaternary material system

may be used as the binder 406. In some embodiments, the binding material can be a quaternary system comprising copper (47 - 58 wt.% or about 47 - about 58), manganese (23 -

25 wt.% or about 23 - about 25 wt.%), nickel (14 - 16 wt.% or about 14 - about 16 wt.%)

and zinc (7 - 9 wt.% or about 7 - about 9 wt.%).

Drill Bits

[0044] The inventors have discovered that the tungsten carbide particles and

MMCs formed therefrom according to some embodiments of the disclosure can be

particularly useful for applying in mining equipment, such as drills. However, it should be

understood that embodiments are not so limited, and the tungsten carbide particles and

MMCs formed therefrom can be used in a variety of other applications in which abrasion

resistant materials are employed.

[0045] Earth-engaging drill bits are used extensively in industries including the

mining, oil and gas industries for exploration and retrieval of minerals and hydrocarbon

resources. Examples of earth-engaging drill bits include polycrystalline diamond compact

(PDC) bits.

[0046] A drill bit wears when it rubs against a formation of metal or rocks in the

ground or against a metal casing tube. This wear may lead to the loss of function and failure

of the drill bit. During drilling, a cooling and lubricating drilling fluid is circulated through

the drill bit using high hydraulic energies. The drilling fluid may contain abrasive particles,

for example sand, which when impelled by the high hydraulic energies can exacerbate wear

at the face of the drill bit and elsewhere.

[0047] Drill bits may have a body comprising at least one of hardened and

tempered steel, and a metal matrix composite (MMC). A steel drill bit body may have

increased ductility and may be more easily manufactured. A steel drill bit body may be

manufactured using casting and wrought manufacturing techniques, examples of which

include but are not limited to forging or rolled bar techniques. The steel properties after heat

treatment are consistent and repeatable. Fracture of steel-bodied drill bits is infrequent;

however, a worn steel drill bit body may be difficult for an operator to repair.

[0048] A MMC drill bit body may wear more slowly than a steel drill bit body.

Conventional MMC drill bit bodies, however, more frequently fracture during casting and/or

processing and/or use from thermal and mechanical shock. Fracturing may cause an drill bit to be removed from service early due to cosmetic or structural defects within the bit.

Alternatively, conventional MMC drill bit bodies may fail catastrophically with the loss of

part of the cutting structure, which may result in sub-optimal drilling performance and early

retrieval of the drill bit.

[0049] In many cases, it is a wing or blade of a drill bit that fractures. Wing or

blade failures are economically damaging for drill bit manufacturers. The retrieval of a worn

or failed drill bit from a drilled hole, for example a well or borehole, is undesirable. The

non-productive time required to retrieve and introduce into the drilled hole a replacement

drill bit may cost millions of dollars. Drill bits and other earth-engaging tools with increased

wear resistance and lower rates of failure may save considerable time and money. Therefore,

developing an ultra-high-strength MMC for drill bits is desirable to reduce or prevent

fracture during drilling.

[0050] The strength of a sample of an MMC may be determined using a transverse rupture strength (TRS) test. In a TRS test, a load is centrally applied to the cubic

or cylindrically shaped MMC sample that is supported between two points. The rupture

strength is the maximum weight that the MMC can support. A plurality of samples may be

tested to derive a mean strength and a standard deviation which may be used to describe the

MMC. The reliability analysis of the TRS of an MMC can provide additional information

such as the failure possibilities under different stresses.

[0051] While MMC drill bits can generally perform better in erosion than steel

bits, they still may encounter rapid deceleration of particles in hydraulic fluids, resulting in

the erosive removal of material. During drilling, high-velocity drilling-mud exits nozzles to

cool the bit and evacuate detritus. Drilling mud contains materials such as bentonite, clay

and surfactants, which also contain hard and angular minerals from the rock material. The

contact between the PDC bits and drilling mud may erode portions of the drill bits. The

MMC disclosed herein has high erosion resistance accompanied with ultrahigh strength to

improve the reliability and performance of the drill bits during drilling.

[0052] FIG. 5 shows a perspective view of an embodiment of earth-engaging tool

in the form of a drill bit 500 which comprises a bit body 502 comprising an MMC FIG.300.

Some, or all, of the bit body 502 may be formed from embodiments of the MMC 300. In

some embodiments, a majority of the bit body 502 is formed from embodiments of the MMC

300. Further, the tool can include a nozzle port 516, e.g., for hydraulic fluid, a face 510 that

supports cutting element 508, such as polycrystalline diamond compact (PDC) cutters, and

junk slots 506 for carrying cuttings away in a fluid from a face of the drill bit 500.

[0053] It should be appreciated, however, that other embodiments of a tool may

have some or none of the described structural features, or may have other structural features.

The bit body 502 can have protrusions in the form of radially projecting and longitudinally

extending wings or blades 504, which are separated by channels at the face 510 of the drill

bit 500 and junk slots 506 at the sides of the drill bit 500. A plurality of cemented tungsten

carbide or PDC cutting elements 508 can be brazed within pockets on the leading faces of the

blades 504 extending over the face 510 of the bit body 502. The PDC cutting elements 508

may be supported from behind by buttresses 512, for example, which may be integrally

formed with the bit body 502.

[0054] The drill bit 500 may further include a shank 514 in the form of an

American Petroleum Institute (API) threaded connection portion for attaching the drill bit

500 to a drill string (not shown). Furthermore, a longitudinal bore (not shown) can extend

longitudinally through at least a portion of the bit body 502, and internal fluid passageways

(not shown) may provide fluid communication between the longitudinal bore and nozzles

516 provided at the face 510 of the bit body 512 and opening onto the channels leading to

junk slots 506 for removing the drilling fluid and formation cuttings from the drill face.

[0055] During formation cutting, the drill bit 500 is positioned at the bottom of a

hole and rotated while weight-on-bit is applied. A drilling fluid - for example a drilling mud

delivered by the drill string to which the drill bit 500 is attached - is pumped through the

bore, the internal fluid passageways, and the nozzles 516 to the face 510 of the bit body 502

and PDC cutting elements 508. As the drill bit 508 is rotated, the PDC cutting elements 508

scrape across, and shear away, the underlying earth formation. The formation cuttings mix

with, and are suspended within, the drilling fluid and pass through the junk slots 506 and up

through an annular space between the wall of the hole (in the form of a well or borehole, for

example), and the outer surface of the drill string to the surface of the earth formation.

Physical Properties

[0056] The strength of a sample of a MMC may be determined using a TRS test,

but using averaging and using other statistical methods to analyze the TRS results may also

be important. If the values are not thoroughly analyzed, the TRS data may not:

1. indicate the likelihood of failure;

2. access the probability of failure at a given stress value; and/or

3. allow measurement of changes or improvements to powder compositions and

the MMCs made with the powders, in particular the relationship between

stress and reliability.

[0057] The strength distribution in a population of samples of the MMC used in

earth-engaging and other tools may be determined using Weibull statistics, which is a

probabilistic approach that enables a calculation of the likelihood of failure to be established

at a given applied stress. Embodiments of the disclosed MMCs may be used with an earth-

engaging tool, e.g., a drill bit 500, for example, which generally follow a Weibull

distribution.

[0058] A Weibull strength distribution is described by the function:

F

[0059] The variables in the equation are: F, which is the probability of failure for

a sample; o, which is the applied stress; ow which is the lower limit stress needed to cause

failure, which is often assumed to be zero; , which is the characteristic strength; m, which

is the Weibull modulus, a measure of the variability of the strength of the material; and V,

which is the volume of specimen.

[0060] The above equation is typically rearranged and presented on a double

logarithmic plot of (1/(1- F))) versus logarithm of and the slope used to calculate m,

assuming ou is zero.

[0061] FIG. 6 illustrates a Weibull plot of empirical strength data for a plurality

of samples of the same type of angular MMC 602 similar to those shown in FIG. 2,

containing predominately angular particles and an MMC containing predominately

spheroidal or substantially spherical particles 604 similar to those shown in FIG. 3. The

MMCs illustrated in FIG. 6 are composed of textured spheroidal or substantially spherical

tungsten carbide and a Cu53 copper binder, a known copper alloy. The y-axis values on the left most y-axis are indicative of a function of the probability of failure, the y-axis values on the right most y-axis are indicative of a percentage probability of failure. The x-axis values are indicative of a function of the applied stress at the time of failure during a TRS test. The empirical strength data for the samples of angular MMC 602 and the sample of spherical

MMC 604 follow a Weibull distribution. The slope of each line defines the respective

Weibull moduli. The angular MMC 602 has a Weibull modulus of 13.76 and the spherical

MMC 604 has a Weibull modulus of 27.94. The Weibull modulus is one measure of material

strength variability. For example, for a Weibull modulus of 4, there will be a 30% variation

(one standard variation) in strength.

[0062] In some embodiments, the spherical MMC 604 has a Weibull modulus of

15 (or about 15), 20 (or about 20), 25 (or about 25) or greater, or a value in range

defined by any of these values.

[0063] A Weibull plot can be used to design drill bit body blade heights and

widths to a predetermined failure rate, and particularly help determine how thin and tall the

drill bit body blades can be for the predetermined failure rate. A taller and thinner blade may

remove a formation faster than a shorter wider blade. However, a taller and thinner blade

may have an unacceptable probability of failure. Alternatively, the reliability of a drill bit

comprising angular MMC 604 can be compared the reliability of another identically

configured drill bit comprising spherical MMC 602.

[0064] Linear extrapolation to a 1 in 10,000 probability of failure equates to

applied stress of about 60 ksi (kilopound per square inch) for an angular MMC 602 and 188

ksi for aspherical MMC 604. In some embodiments, the linear extrapolation to a 1 in 10,000

probability of failure for the spherical MMC 604 equates to 80 (or about 80) ksi or greater,

100 (or about 100) ksi or greater, 120 (or about 120) ksi or greater, 140 (or about 140) ksi or

greater, 160 (or about 160) ksi or greater, 180 (or about 180) ksi or greater, or a value in a

range defined by any of these values.

Microstructure

[0065] The inventors have discovered that the novel spheroidal or substantially

spherical fused tungsten carbide has a textured surface. The inventors have further

discovered that this texture can increase the available surface area at the interface 306 between the soft phase 304 and the spheroidal or substantially spherical fused tungsten carbide particles 302, as shown in FIG. 3.

[0066] The strength of an MMC system can be associated with one or more of

three different components: the strength of the copper binder, the strength of the tungsten

carbide particles, and/or the binding strength between the copper binder and the incorporated

tungsten carbide particles. Thus, if the tungsten carbide particles and copper do not bond

well, a failure can occur when the MMC undergoes high stress. By having carbide particles

with larger surface areas, the alloy has more area to bond to the carbide particles, thus

increasing the interfacial strength.

[0067] FIG. 7 illustrates the surface morphology of a tungsten particle in a

conventional MMC. As shown, the microstructure has soccer-ball-like topographical

features of conventional fused tungsten carbide particles. The surface is relatively smooth,

resulting in a low surface area and relatively low interfacial strength when incorporated

within a MMC.

[0068] FIG. 8 illustrates the surface morphology of a spheroidal or substantially

spherical tungsten particle in an MMC. The microstructure includes needle-like

topographical features (e.g., texturing) of spheroidal or substantially spherical fused tungsten

carbide. The surface is mostly textured with a fine-grained structure, resulting in a high

surface area and better interfacial strength when incorporated within a MMC.

[0069] FIG. 9 illustrates the surface morphology of a spheroidal or substantially

spherical tungsten particle in an MMC. The microstructure includes dense needle-like like

topographical features of spheroidal or substantially spherical fused tungsten carbide. The

surface is mostly textured with a finer grained structure resulting in an even higher surface

area and exceptional interfacial strength when incorporated within a MMC.

[0070] To quantify the spheroidal or substantially spherical fused tungsten

carbide particles by their surface features, the fraction of a surface area in a fixed view field

of an optical or scanning electron microscope (SEM) image that can be attributed to grain

boundaries is analyzed. An area fraction of grain boundaries refers to the area in an image,

e.g., an optical or SEM image, of a surface of a sample, e.g., the surface of a tungsten carbide

particle, that can be attributed to grain boundaries. The area fraction of grain boundaries can

be quantified using images, e.g., high contrast or binary images such as those shown in FIG.s

10-12. For example, the number of dark pixels as a fraction of a total number of pixels

within an imaged field can correspond the area fraction of grain boundaries. The inventors

have discovered that the conventional soccer-ball-like surface morphology of tungsten

carbide particles leads to a relatively low area fraction of grain boundaries on the surface of

the tungsten carbide particles, e.g., less than 5%. The needle-like surface morphology of

tungsten carbide particles of spheroidal MMCs leads to a relatively high area fraction of

grain boundary on the surface of the tungsten carbide particles, e.g., over 10% (or about

10%). For example, the area fraction of the grain boundary in FIG. 10, which is a binary

image of the MMC of FIG. 7, which illustrates a conventional MMC, is 3.6%. In contrast,

the area fraction of the grain boundary in FIG. 11, which is a binary image of the MMC of

FIG. 8, which illustrates a MMC made from spheroidal or substantially spherical tungsten

carbides, is 14.2%. FIG. 12, a binary image of FIG. 9, illustrates a MMC made from

spheroidal or substantially spherical tungsten carbides in which the area fraction of grain

boundaries is 20.1%. A high area fraction of grain boundaries may lead to more uniform and

finer grains overall.

[0071] The inventors have discovered that the combination of the spheroidal

shape of the tungsten carbide particles, and the needle-like surface morphology of the formed

MMC, may give rise to a relatively high surface area of the tungsten carbide particles, which

in turn gives rise to the relatively high grain boundary area fraction. The high gran boundary

area fraction can be proportional to the amount of high strength interfaces formed between

the tungsten carbide particles and the metal matrix. High amounts of high strength interfaces

can lead to improved mechanical and tribological properties of MMCs, including high TRS

values and increased erosion resistance.

[0072] The needle-like topography comprises needle-like structures that are

elongated along surfaces of the tungsten carbide particles. The needle-like structures have at

least a portion length portion having a length exceeding, e.g., 0.5, 1, 2, 3, 4, 5 µm, or a value

in a range defined by any of these values, while having a width that is less than 2, 1, 0.5, 0.2,

0.1 µm, or a value in a range defined by any of these values. The needle-like structures may

have a ratio of the longest length to the smallest width of the needle like structures that

exceeds 2, 5, 10, 20 or a value in a range defined by any of these values.

[0073] In some embodiments of this disclosure, the spheroidal or substantially

spherical fused tungsten carbide particles have a grain boundary area fraction of 5.0% (or

about 5.0%) or greater. 10.0% (or about 10.0%) or greater, 12.0% (or about 12.0%) or

greater, 12.0% (or about 12.0%) or greater, 20.0% (or about 20.0%), or a value in a range

defined by any of these values.

[0074] Homogeneity of the grain boundary distribution in the particle surface was

also characterized. Each microstructural image of FIGS. 10-12 were separated into nine

equal parts. The grain boundary area fraction in each separated part was measured

individually. Then the variation of the grain boundary area fraction for the nine equal parts

was calculated. The lower the value of variance, the more uniform the distribution of the

grain boundaries. This lower variation can provide for improved strength of the MMC. For

example, the variation in FIG. 10 was measured to be 3.8%, which is lower than the value

measured in FIG. 11, which was 9.4%, indicating a more uniform distribution of grain

boundaries in FIG. 11 relative to FIG. 10.

[0075] FIG. 10 illustrates a binary image of FIG. 7. FIG. 11 shows a binary image

of FIG. 8, which includes an analyzed area fraction of 14.2% and variation of 9.4% when

divided into nine parts. FIG. 12 shows a binary image of FIG. 9, which includes an analyzed

area fraction of 20.1% and variation of 3.8% when divided into nine parts.

Physical Properties

[0076] In some embodiments, the size of the spheroidal or substantially spherical

fused tungsten particle may between 1 to 200 µm. The variation of the size of the spheroidal

or substantially spherical fused tungsten particle can result in the change in TRS of the final

infiltrated MMC.

[0077] Powder particle size distribution is measured and determined by

MicroTrac per ASTM B822, hereby incorporated by reference in its entirety. The powder

particle size distribution is defined by describing values, namely:

- D10 or 10th percentile particle diameter (µm)

- D50 or average particle diameter (µm)

- D90 or 90th percentile particle diameter (um)

[0078] The inventors have discovered that the D50 of tungsten carbide particles

can be tuned to achieve a target TRS value. In some embodiments, an MMC formed from

spheroidal or substantially spherical fused tungsten carbide particles that have an average

particle size (D50) between 1 µm and 10 µm, has a TRS greater than or equal to 360 ksi (or

about 360 ksi, greater than or equal to 530 ksi (or about 530 ksi), greater than or equal to 700

ksi (or about 700 ksi), or a value in a range defined by any of these values.

[0079] In some embodiments, the MMC formed from spheroidal or substantially

spherical fused tungsten carbide particles that have an average particle size (D50) between 11

µm and 20 µm, has a TRS greater than or equal to 280 ksi (or about 280 ksi), greater than or

equal to 365 ksi (or about 365 ksi), greater than or equal to 450 ksi (or about 450 ksi), or

value in a range defined by any of these values.

[0080] In some embodiments, the MMC formed from spheroidal or substantially

spherical fused tungsten carbide particles that have an average particle size (D50) between 21

µm and 40 µm, has a TRS greater than or equal to 230 ksi (or about 230 ksi), greater than or

equal to 260 ksi (or about ksi), greater than or equal to 290 ksi (or about 290 ksi), or a value

in a range defined by any of these values.

[0081] In one embodiment, the MMC formed from spheroidal or substantially

spherical fused tungsten carbide particles that have an average particle size (D50) between 41

µm and 60 µm, has a TRS greater than or equal to 180 ksi, greater than or equal to 200 ksi,

greater than or equal to 220 ksi, or a value in a range defined by any of these values.

[0082] In some embodiments, the MMC formed from spheroidal or substantially

spherical fused tungsten carbide particles that have an average particle size (D50) between 61

µm and 80 µm, has a TRS greater than or equal to 160 ksi (or about 160 ksi), greater than or

equal to 170 ksi (or about 170 ksi), greater than or equal to 180 ksi (or 180 ksi), or a value in

a range defined by any of these values.

[0083] In some embodiments, the MMC formed from spheroidal or substantially

spherical fused tungsten carbide particles that have an average particle size (D50) between 81

µm and 100 µm, has a TRS greater than or equal to 140 ksi (or about 140 ksi), greater than or

equal to 150 ksi (or about 150 ksi), greater than or equal to 160 ksi (or about 160 ksi), or a

value in a range defined by any of these values.

[0084] In some embodiments, the MMC formed from spheroidal or substantially

spherical fused tungsten carbide particles that have an average particle size (D50) between

101 µm and 200 µm, has a TRS greater than or equal to 100 ksi (or about 100 ksi), greater

than or equal to 120 ksi (or about 120 ksi), greater than or equal to 140 ksi (or about 140 ksi),

or a value in a range defined by any of these values.

[0085] Laboratory testing enabled the abrasion and erosion resistance of angular

and spherical MMCs to be measured and compared to one another.

[0086] An erosion test simulating real drilling condition was carried out by using

a modified high-pressure abrasive waterjet cutting machine. A special sample holder

adjustable between 0° and 90° relative to the waterjet was designed to allow the adjustment

of the impacting angle between the sample surface and slurry jet produced by the waterjet

cutting machine. The distance between the nozzle and the sample was selected as 1,000 mm

in order to avoid cutting the sample and to enlarge the contact area between the jet and

sample. Garnet was used as the erodent. The pressure of the waterjet was 50 ksi and the test

duration was 10 min. A balance with an accuracy of 1 mg was used to measure the weight of

the coupon before and after the test.

[0087] An MMC sample produced from spherical fused tungsten carbide particles

and made by liquid infiltration was tested for erosion at a 30° impact angle with volume loss

of 0.022 cm³. A reference MMC made from angular fused tungsten carbide particles was

tested under the same conditions and experienced a volume loss of 0.17 cm³.

[0088] In some embodiments, the spherical MMC has an erosive volume loss of

0.10 (or about 0.10) cm³ or less , 0.08 (or about 0.08) cm³ or less, 0.06 (or about 0.06) cm³ or

less, 0.04 (or about 0.04) cm³ or less, or a value in a range defined by any of these values.

[0089] A standard ASTM 611 high stress abrasion test, hereby incorporated by

reference in its entirety, was performed on an MMC produced from spherical fused tungsten

carbide particles and a reference MMC made from angular fused tungsten carbide particles

An MMC produced from spherical fused tungsten carbide particles under the testing conditions had volume loss of 0.51 cm³ while a reference MMC made from angular fused

tungsten carbide particles had a volume loss of 1.28 cm³ under the same testing conditions.

[0090] In some embodiments of this disclosure, the spherical MMC has an ASTM

611 volume loss of 1.00 (or about 1.00) cm³ or lower, 0.80 (or about 0.80) cm³ or lower, 0.60

(or about 0.60) cm³ or lower, or a value in a range defined by any of these values.

High Thermal Conductivity and Low Melting Temperature Feedstock Alloy, Metal Matrix Formed from the Feedstock Alloy, and MMC formed using the Feedstock Alloy

[0091] As described above, metal matrix composite materials (MMCs) include

reinforcement particles embedded in a matrix. The physical properties of the reinforcement

particles and the matrix can synergistically complement each other to form a metal matrix

composite material that has a unique set of properties that are difficult to achieve with a

single material. For example, as described above, an MMC that includes tungsten carbide

particles embedded in a Cu-based matrix can provide a combination of high strength and

high hardness, which can be difficult to achieve simultaneously in a single material.

[0092] As described above, one technology area that can benefit from MMCs is

drilling technology, e.g., earth drilling technology for extracting hydrocarbon fuel.

Components used in drilling, e.g., drill bits, should exhibit superior strength, hardness and

wear resistance. In addition, the combination of these properties can be demanded under

relatively harsh conditions for some applications. The harsh conditions may include high

temperature, which can result from friction caused by operation of the drill bits. The

performance levels of some MMCs, which may be sufficient at moderate temperatures, may

degrade to unacceptable performance levels at elevated temperatures. Thus, there is a need

for MMCs that combine the various advantageous mechanical properties of MMCs based on

tungsten carbide particles embedded in a Cu-based matrix, while also being designed to

maintain the advantageous properties under heat-generating conditions by efficiently

dissipating heat.

[0093] Accordingly, MMC made from spheroidal or substantially spherical fused

tungsten carbide particles increase the thermal shock resistance of components fabricated

therefrom. In some embodiments, an alloy, e.g., a feedstock alloy, configured to form a

matrix of an MMC having high thermal conductivity, for various applications including

drilling is produced. The MMCs formed using the feedstock alloy can maintain various

advantageous performance criteria as described above, in in addition to significantly improving the thermal shock resistance of the MMCs. The reduction of thermal shock can in turn reduce fracture failures. For drilling applications, reduction of the tendency of the drill bit body to fracture during operation can significantly improve productivity and reduce cost associated with replacement or repair thereof.

[0094] It should be appreciated that, in addition to having high thermal

conductivity, to serve as a synergistic matrix of an MMC, the feedstock alloy for forming the

matrix should be compatible with and integrate well with the reinforcement particles. This is

in part because, as described above, one of the processes for fabricating MMCs involves

infiltration of the network of pores formed by the reinforcement particles. To serve as an

effective infiltrant, the alloy for forming the matrix can have a melting temperature below

that of the reinforcement particles. The alloy, when melted, should have a high fluidity to

provide the surface tension and capillary force for facilitating the infiltration process. In a

liquid state, the alloy should form a low contact angle with the surfaces of the reinforcement

particles. Furthermore, any chemical reaction between the alloy and the reinforcement

particles should be kept to a relatively low level, as such reactions can impede the infiltration

process by altering the composition of the matrix relative to the feedstock alloy, as well as

detrimentally affecting the performance of the resulting MMC.

[0095] To address these and other needs, a feedstock alloy for forming a matrix of

an MMC includes an elemental composition including copper (Cu) as a majority element.

Some reinforcement particles, such as some tungsten carbide particles, have relatively low

thermal conductivity, and the thermal conductivity of the MMC may be limited by that of a

matrix having a relatively high thermal conductivity. Furthermore, in the context of drill

bits, as tungsten carbide content is increased the thermal conductivity of the MMC can drop

proportionally due to a corresponding reduction in the volume fraction of the matrix. The

reduction in thermal conductivity of the MMC with increasing reinforcement particle content

can be offset by incorporating a relatively high copper content. However, some tungsten

carbide particles can have a higher thermal conductivity than the MMC. Regardless, unlike

some relatively isolated reinforcement particles, because the matrix can form an

interconnected network through which heat can transfer, and/or because the matrix

constitutes a substantial thermal mass faction of the resulting MMC, higher thermal

conductivity of the matrix is nevertheless desirable.

[0096] According to various embodiments, a feedstock alloy for forming a matrix

of an MMC includes an elemental composition including a copper (Cu) concentration

exceeding 55, 60, 65, 70, 75, 80, 85 weight percent (wt. %), or a value in a range defined by

any of these values. The high Cu content can provide improved thermal conductivity, among

other advantages.

[0097] While elemental copper may offer one of the highest thermal conductivities, it may not offer one or more other desirable characteristics associated with the

fabrication of the MMC or the resulting mechanical properties thereof. To improve various

mechanical properties of the matrix including strength, hardness and abrasion resistance of

the matrix of the MMC, which in turn improves the corresponding mechanical properties of

the resulting MMC, as well as improving infiltration characteristics described above for

forming the matrix in liquid state, the inventors have discovered a combination of alloying

elements for alloying with Cu to form a feedstock alloy for forming the matrix. According to

various embodiments, in addition to the relatively high Cu content described above, the

elemental composition of the feedstock alloy for forming the matrix includes: tin (Sn) at a

concentration exceeding 1.4 wt. %, nickel (Ni) at a concentration exceeding 3.5 wt. %, and

manganese (Mn) at a concentration exceeding 5.6 wt. %. To maintain the high Cu content

described above, the combined concentration of Sn, Ni and Mn is less than 20 wt.%, 30 wt.

%, 40 wt. %, 45 wt. % or a value in a range defined by any of these values, according to

embodiments.

[0098] In some embodiments, an elemental composition of a feedstock alloy for

forming a matrix of an MMC includes Sn at a concentration exceeding 1.4, 1.6, 1.7, 1.8, 1.9,

2.0, 2.1, 2.2, 2.3, 2.4, 2.6, 2.8, 3.0, 3.2, 3.4, 3.6, 3.8, 4.0 wt. %, or a concentration within a

range defined by any of these values. In some embodiments, the elemental composition may

include Sn at 1.4-4 wt. %, 1.7-2.3 wt. %, or about 2.0 wt. %. In some embodiments, the

elemental composition of the feedstock alloy additionally includes Mn at a concentration

exceeding 5.6, 6.4, 6.8, 7.2, 7,6, 8.0, 8.4, 8.8, 9.2, 9.6, 10.4 wt. %, or a concentration within a

range defined by any of these values. In some embodiments, the elemental composition

includes Mn at 5.6-10.4 wt. %, 6.8-9.2 wt. %, or about 8.0 wt. %. In some embodiments, the

composition of the feedstock alloy additionally includes Ni at a concentration exceeding 3.5,

4.0, 4.3, 4.5, 4.7, 5.0, 5.3, 5.5, 5.8, 6.0, 6.5 wt. %, or a concentration in a range defined by any of these values. In some embodiments, the elemental composition includes Ni at 3.5-6.5 wt. %, 4.3-5.8 wt. %, or about 5.0 wt. %.

[0099] In some embodiments, the elemental composition of the feedstock alloy

may include additional elements, which may include incidental impurities, at a combined

concentration less than 10 wt. %, 5 wt. %, 2 wt. %, 1 wt. % or a value in a range defined by

any of these values. In some embodiments, Cu may be present as a balance of the elemental

composition, in addition to the additional or impurity elements.

[0100] Advantageously, the relatively high Cu concentration of the feedstock can

provide high thermal and/or electrical conductivity. It will be appreciated that the high

thermal conductivity can be indirectly measured by measuring the electrical conductivity of

the allow. In some embodiments, the feedstock has an electrical conductivity greater than

2.0 mega Siemens (MS)/meter (m), 2.5 MS/m, 3.0 MS/m, 3.5 MS/m, or a value in a range

defined by any of these values. Without being bound to any theory, the feedstock can have

thermal conductivity that can have a value related to the electrical conductivity through, e.g.,

Wiedemann-Franz's law. Wiedemann-Franz's law states that the ratio of the electronic

contribution of the thermal conductivity to the electrical conductivity is proportional to the

temperature. According to embodiments, the feedstock can have thermal conductivity

greater than 10 W/mK, 11 W/mK, 12 W/mK, 13 W/mK, 14 W/mK, 15 W/mK, 16 W/mK or

a value in a range defined by any of these values.

[0101] When present in the disclosed amounts, the combination of Cu, Sn, Mn

and Ni forms a feedstock alloy that can provide various advantages over relatively pure

elemental Cu as a source of the matrix of an MMC. The advantages may include in one or

more of: lower melting temperature, lower contact angle with tungsten carbide and/or lower

reactivity with tungsten carbide. The combination of elements can additionally provide

advantages over relatively pure elemental Cu as source of the matrix of an MMC including

one or more of: higher strength, higher abrasion resistance and/or higher hardness.

[0102] In some embodiments, the combination of the elements in the feedstock

alloy can provide further advantages over elemental Cu when the elemental composition of

the feedstock does not include one or more of Si, B and/or Zn, or when present, Si, B and/or

Zn is present at a combined concentration less than 10 wt. %, 5 wt. %, 2 wt. %, 1 wt. % or a

value in a range defined by any of these values.

[0103] In various embodiments, the feedstock alloy for forming a matrix of an

MMC is a pre-formed alloy that is solidified from a liquid having the alloy composition, e.g.,

by melting the constituent elements at a temperature sufficient to melt each of the constituent

elements. Having the feedstock in the form of a preformed alloy, as opposed to a mixture of

elemental powder, can provide various advantages can lower the melting temperature of the

feedstock alloy, such that the MMC can be effectively formed at lower temperatures. The

lower feedstock melting temperature can make different chemical compositions of feedstocks

compatible with existing methods for manufacturing MMCs, including those described

above. Due to the temperature constraints of some existing manufacturing methods, a

feedstock for forming the matrix of an MMC that has a melting temperature exceeding

1300K may be difficult to fully melt to infiltrate the reinforcement particles for

manufacturing into a matrix of an MMC. Thus, based on the melting temperatures of Cu,

Mn and Ni, which are 1083 °C (1356 K), 1244 °C (1517 K), 1453 °C (1726 K), respectively,

the inventors have found it advantageous for the feedstock including these elements to be in

an alloy form that has a melting temperature lower than each of these individual elements.

Thus, according to embodiments, the feedstock in the form of an alloy has a composition

such that the alloy has a solidus temperature lower than a melting temperature of

substantially pure Cu. In some embodiments, the solidus temperature of the alloy is lower

than 1300 K, 1275K, 1250K, 1225K, 1200K, or a solidus temperature in a range defined by

any of these values.

[0104] In some embodiments, the feedstock alloy can be present as, or liquefied

and solidified into, a single phase solid solution. An alloy or matrix in the form of a single

phase solid solution can provide advantages in various mechanical and thermal properties

over a multi-phase alloy. Without being bound to any theory, when present as a single phase

solid solution, thermal conductivity can be enhanced due to, e.g., the suppression of phonon

scattering that can occur at phase boundaries. The absence of phase boundaries can also

enhance the strength of the alloy by reducing boundary-originating defects such as

dislocations.

[0105] The inventors have found that one measure of the availability of an alloy

as a single phase solid solution is a temperature range below the solidus temperature within

which the alloy is present, or predicted to be present under thermodynamic equilibrium conditions, as a single phase solid solution. Such temperature range may be referred to as a single phase temperature range. In some embodiments, the elemental composition of the alloy comprising Cu, Sn, Mn and Ni as disclosed herein has a single phase temperature range greater than 400K such that, from the solidus temperature down to at least 400K below the solidus temperature, the alloy forms a single phase solid solution having a face-centered cubic (FCC) crystal structure. In some embodiments, the single phase temperature range of the feedstock alloy below the solidus temperature within which the alloy is present may exceed 375K, 400K, 425K, 450K, 475K or a value in a range defined by any of these temperatures.

[0106] The FCC crystal structure may correspond to a base crystal structure of Cu

in which Sn, Mn and Ni can be present as substitutional and/or interstitial elements. When

the feedstock alloy has a relatively wide single phase temperature range as described herein,

the feedstock alloy can be formed into a matrix that is substantially present as a single phase

alloy at room temperature. In some embodiments, , at room temperature, greater than 80 wt.

%, 85 wt. %, 90 wt. %, 95 wt. % or a value in range defined by any of these values, of the

alloy and the resulting matrix is present a single phase solid solution having a face-centered

cubic (FCC) crystal structure.

[0107] The feedstock alloy as described herein can be used to form a metal matrix

composite (MMC) material comprising reinforcement particles embedded in a copper-based

matrix. A formed copper-based matrix can have any and/or all of the physical and chemical

characteristics of the feedstock alloy used to form the matrix as described, including the

elemental composition. In some embodiments, the chemical composition of feedstock alloy

and a matrix of a MMC material formed therefrom can be substantially the same. For

example, in some embodiments, the matrix of an MMC has an elemental composition

including copper (Cu) exceeding 55 weight percent (wt. %) and tin (Sn) exceeding 1.4 wt. %.

Similar to the feedstock alloy, the elemental composition of the matrix includes Sn at a

concentration exceeding 1.4, 1.6, 1.7, 1.8, 1.9, 2.0, 2.1, 2.2, 2.3, 2.4, 2.6, 2.8, 3.0, 3.2, 3.4,

3.6, 3.8, 4.0 wt. %, or having a concentration within a range defined by any of these values;

Mn at a concentration exceeding 5.6, 6.4, 6.8, 7.2, 7,6, 8.0, 8.4, 8.8, 9.2, 9.6, 10.4 wt. %, or a

concentration within a range defined by any of these values; and Ni at a concentration exceeding 3.5, 4.0, 4.3, 4.5, 4.7, 5.0, 5.3, 5.5, 5.8, 6.0, 6.5 wt. %, or a concentration in a range defined by any of these values.

[0108] Similarly, the matrix of the MMC can have any and/or all of the physical

and chemical characteristics of the feedstock alloy, including the solidus temperature, the

single phase temperature range, electrical conductivity and thermal conductivity as described

above, overlapping details of which are omitted here for brevity.

[0109] According to various embodiments, the reinforcement particles can

include tungsten carbide particles. The tungsten carbide particles can have any and/or all of

the characteristics of the spheroidal tungsten carbide particles described above, overlapping

details of which are omitted herein for brevity. For example, in some embodiments, the

tungsten carbide particles can have a spheroidal shape having ratio of a first length along a

major axis to second length along a minor axis that is 1.20 or lower. In some embodiments,

the tungsten carbide particles have a surface that is textured to have a grain boundary area

fraction greater than 5.0 %. In some embodiments, the tungsten carbide particles can have a

D50 between 1 µm and 10 µm; between 11 µm and 20 µm; between 21 µm and 40 µm;

between 41 µm and 60 µm; between 61 µm and 80 µm; between 81 µm and 100 µm; between 101 µm and 200 µm; or a value in a range defined by any of these values, where the

dimension D refers to the longest lateral dimension of the reinforcement tungsten carbide

particles, and D50 refers to a median value of the longest lateral dimensions of the tungsten

carbide particles.

[0110] However, the reinforcement particles of MMC materials according to

embodiments are not so limited, and in some other embodiments, the tungsten carbide

particles can have a spheroidal shape having a ratio of a first length along a major axis to

second length along a minor axis that is 1.20 or greater, and/or a surface that is textured to

have a grain boundary area fraction lower than 5.0%..

[0111] In some embodiments, the tungsten carbide particles do not have a

spheroidal shape and/or a textured surface. FIG. 13 illustrates an optical micrograph of a

MMC comprising tungsten carbide particles 1301 embedded in a Cu-based matrix 1302,

according to embodiments. Unlike the spheroidal tungsten carbide particles of the MMC

described above with respect to FIG. 3, and similar to the tungsten carbide particles of the

MMC described above with respect to FIG. 2, the tungsten carbide particles 1301 of the

MMC illustrated in FIG. 13 are angular particles having irregular shapes.

[0112] According various embodiments, the reinforcement particles, e.g.,

tungsten carbide particles, are present in the MMC including the Cu-based matrix at greater

than 40 vol. %, 50 vol. %, 60 vol. %, 70 vol. %, 80 vol. %, or a value in a range defined by

any of these values, for example 50-70 vol. %.

[0113] The MMCs according to embodiments can be fabricated using a method

similar to that described above with respect to FIG. 4, overlapping details of which are

omitted herein for brevity. For example, referring back to FIG. 4, a method of forming a

metal-matrix composite (MMC) material comprises providing reinforcement particles 408,

e.g., tungsten carbide particles, and a feedstock alloy 410 for forming a copper-based matrix

in a mold assembly 412, 414, wherein the feedstock alloy 410 has an elemental composition

including copper (Cu) exceeding 55 weight percent (wt. %) and tin (Sn) exceeding 1.4 wt. %.

The reinforcement particles 408 are disposed below the feedstock alloy 410 such that gravity

pulls liquefied alloy 410 into a porous network formed by the reinforcement particles 408.

Subsequently, the method further comprises melting the alloy 410, infiltrating a network of

pores formed by the reinforcement particles 408 with the liquefied alloy 410, and wetting the

surfaces of the reinforcement particles 408. Subsequently, the liquefied alloy 410 is

solidified within the network to form the MMC material comprising the reinforcement

particles 408 embedded in in the copper-based matrix.

[0114] As described above, because the feedstock is in the form of an alloy 410,

the feedstock can be liquefied at temperatures substantially lower than the melting

temperatures of at some of the elemental metals including Cu, Mn and Ni. According to

embodiments, melting comprises heating the mold to a temperature lower than melting

temperatures of one or more of Cu, Mn and Ni, or lower than 1083 °C (1356 K), 1244 °C

(1517 K), 1453 °C (1726 K). For example, melting comprises heating the mold to a

temperature of 1000-1200 °C. Thus fabricated MMCs can form at least a portion of a drilling

component, such as a drill bit as described above, the details of which are omitted herein for

brevity.

[0115] As described above, one mechanical property that is a measure of strength

of an MMC is the transverse rupture strength (TRS), the measurement details of which are not repeated herein for brevity. The MMCs according to embodiments, when fabricated with tungsten carbide particles and Cu-based alloys as described above, can have TRS values greater than 175 ksi, 200 ksi, 220 ksi, 250 ksi, or a value in a range defined by any of these values.

[0116] The Cu-based alloys disclosed herein provide additional toughness when

used as the binder component in MMCs. The Cu-based alloys can have toughness levels of

greater than 3,000 in*lbf/in³, 4,000 in*lbf/in³, 5,000 in*lbf/in³, or a value in a range defined

by any of these values.

[0117] FIG. 14 shows example samples that have been prepared for testing

MMCs having Cu-based matrix and tungsten carbide particles as described herein. For

measuring the TRS of MMCs according to embodiments, cylindrical MMC samples having

0.5 mm diameter and 100 mm length were prepared using a graphite mold with appropriate

dimensions, by first filling the mold with tungsten carbide particles and placing pieces of the

Cu-based feedstock alloy over the tungsten carbide particles. The mold was then placed in a

furnace at a temperature of 1180 °C for a period of 1 hour to melt the Cu-based alloy and

infiltrate the tungsten carbide particles with the liquefied Cu-based alloy, and subsequently

solidifying the alloy to form the final MMC cylindrical samples as shown. The cylindrical

samples were then tested using a standard 3 point bend test to measure the transverse rupture

strength. The illustrated samples were fabricated using spherical tungsten carbide particles

with a particle size distribution (PSD) defined by upper and lower size limit of 32-75 microns

(corresponding to 200 mesh and 450 mesh and a D50 of 70 microns). The prepared MMC

cylindrical samples as shown in FIG. 14 were demonstrated to have a TRS of 175-250 ksi.

[0118] Cylindrical MMC samples made from a Cu53 alloy and a chemistry according to an embodiment above, e.g. a disclosed Cu alloy, were manufactured by a similar

process as described above. The MMC sample using a Cu53 alloy had a thermal conductivity of 13.96 W/mK and the drill bit sample using the disclosed alloy had a thermal

conductivity of 16.77 W/mK. The MMC sample using the disclosed copper alloy had an

average TRS strength of 240 ksi, above that of the Cu53 alloy, 224 ksi. The comparative

experimental results are illustrated in Table 1. The elastic modulus of the disclosed copper

alloy, 320 GPa, was lower than for the Cu53 alloy, 340 GPa.

Table 1: Transverse Rupture Strength (ksi) Comparison

Disclosed Cu Sample # Alloy Cu53 1 243 217 2 240 225 3 247 223 4 244 243 5 244 217 6 228 219 Mean 241 224

[0119] The TRS testing revealed that the disclosed Copper alloy also exhibits

improved toughness in the MMC sample in comparison to Cu53 manufactured MMCs. The

Cu53 MMC sample shows a toughness of 2,965 in*lbf/in3, whereas the disclosed Copper

alloys shows a toughness of 5,511 in* lbf/in3.

Table 2: Toughness (in*Ibf/in³) Comparison

Sample Disclosed Cu

# Alloy Cu53 1 5616 2726 2 5492 3024 3 5941 2923 4 5653 3654 5 5798 2688 6 4566 2775 Mean 5511 2965

[0120] FIG. 15 shows TRS testing results of MMCs having Cu-based matrix and

tungsten carbide particles as described herein. A cylindrical MMC sample with a copper-

based matrix comprising 2.89% tin (Sn), 7.56% manganese (Mn), 4.88% nickel (Ni), and

84.67 wt. % of Cu (X17C MMC sample), as well as a reference MMC sample made from a

Cu53 alloy were manufactured by a similar process as described above in FIG. 14. Referring

to FIG. 15, TRS testing was performed on both the Cu53 MMC sample as well as the X17C

MMC sample. The UHS+X17C sample exhibited an increase in both strength and toughness

relative to the Cu53 sample.

Additional Examples I 1. A powder blend comprising fused tungsten carbide particles, wherein the

fused tungsten carbide particles comprise:

a spheroidal shape having ratio of a first length along a major axis to second

length along a minor axis that is 1.20 or lower; and

a surface that is textured to have a grain boundary area fraction greater than

5.0%. 2. The powder blend of Example 1, further comprising metallic tungsten

particles.

3. The powder blend of Examples 1 or 2, wherein the textured surface has a

needle-like topography.

4. The powder blend of any one of Examples 1-3, wherein the needle-like

topography comprises needle-like structures elongated along surfaces of the tungsten carbide

particles, wherein at least some of the needle-like structures have a portion having a width

not exceeding 1 µm.

5. The powder blend of any one of Examples 1-4, wherein the powder blend is

configured to form a metal-matrix composite (MMC) including the fused tungsten carbide

particles embedded in a matrix.

6. The powder blend of Example 5, wherein the matrix comprises copper or a

copper alloy.

7. The powder blend of any one of Examples 1-6, wherein the powder blend is

configured to form a high strength MMC that has a Weibull modulus of 15 or greater.

8. The powder blend of any one of Examples 1-7, wherein the powder blend is

configured to form a high strength MMC that has a linear extrapolation of the Weibull plot

to a 1 in 10,000 probability of failure that equates to an applied stress of 80 ksi or greater.

9. The powder blend of any one of Examples 1-8, wherein the powder blend is

used to form a high strength MMC that has an erosive volume loss of 0.10 cm³ or lower.

10. The powder blend of any one of Examples 1-9, wherein the powder blend is

configured to form a high strength MMC that has an ASTM 611 volume loss of 1.00 cm³ or

lower.

11. The powder blend of any one of Examples 1-10, wherein the powder blend is

configured to form a portion of a high strength drill bit including a metal-matrix composite

(MMC) including the fused tungsten carbide particles and a copper or copper alloy matrix.

12. The powder blend of any one of Examples 1-11, wherein the fused tungsten

carbide particles have an average particle size of 1-200 µm.

13. A metal matrix composite (MMC) material, comprising:

fused tungsten carbide particles having a spheroidal shape and a surface that is

textured to have a grain boundary area fraction greater than 5.0 %; and

a matrix having embedded therein the fused tungsten carbide particles.

14. The MMC material of Example 13, wherein at least some of the fused

tungsten carbide particles have a ratio of a first length along a major axis to second length

along minor axis length that is 1.20 or lower.

15. The MMC material of Examples 13 or 14, wherein the matrix comprises

copper or a copper alloy.

16. The MMC material of any one of Examples 13-15, wherein the MMC material has a Weibull modulus of 15 or greater.

17. The MMC material of any one of Examples 13-16, wherein the MMC material has a linear extrapolation of the Weibull plot to a 1 in 10,000 probability of failure

that equates to an applied stress of 80 ksi or greater.

18. The MMC material of any one of Examples 13-17, wherein the MMC material has an erosive volume loss of 0.10 cm³ or lower.

19. The MMC material of any one of Examples 13-18, wherein the MMC material has an ASTM 611 volume loss of 1.00 cm³ or lower.

20. The MMC material of any one of Examples 13-19, wherein the fused tungsten

carbide particles have a D50 between 1 µm and 10 µm and the MMC material has a

transverse rupture strength of 360 ksi or greater.

21. The MMC material of any one of Examples 13-20, wherein the fused tungsten

carbide particles have a D50 between 11 um and 20 µm and the MMC material has a

transverse rupture strength of 280 ksi or greater.

22. The MMC material of any one of Examples 13-21, wherein the fused tungsten

carbide particles have a D50 between 21 µm and 40 µm and the MMC has a transverse

rupture strength of 230 ksi or greater.

23. The MMC material of any one of Examples 13-22, wherein the fused tungsten

carbide particles have a D50 between 41 µm and 60 µm and the MMC has a transverse

rupture strength of 180 ksi or greater.

24. The MMC material of any one of Examples 13-23, wherein the fused tungsten

carbide particles have a D50 between 61 µm and 80 µm and the MMC has a transverse

rupture strength of 160 ksi or greater.

25. The MMC material of any one of Examples 13-24, wherein the fused tungsten

carbides have a D50 between 81 µm and 100 µm and the MMC has a transverse rupture

strength of 140 ksi or greater.

26. The MMC material of any one of Examples 13-25, wherein the fused tungsten

carbides have a D50 between 101 µm and 200 µm and the MMC has a Transverse Rupture

Strength of 100 ksi or greater.

27. The MMC material of any one of Examples 13-26, wherein the MMC material forms part of a high strength drill bit.

28. A method of forming a metal-matrix composite (MMC) material, the method

comprising:

adding into a mold fused tungsten carbide particles having a spheroidal shape

and a surface that is textured to have a grain boundary area fraction greater than 5.0

%; adding a binder material comprising copper into the mold;

melting the binder material to infiltrate the fused tungsten carbide particles;

and

solidifying the molten binder material to form the MMC material.

29. The method of Example 28, wherein the fused tungsten carbide particles have

the grain boundary area fraction of at least 10.0%.

30. The method of Examples 28 or 29, wherein the fused tungsten carbide

particles have the grain boundary area fraction of at least 12.0%.

31. The method of any one of Examples 28-30, wherein the fused tungsten

carbide particles have the grain boundary area fraction of at least 20.0%.

32. The method of any one of Examples 28-31, wherein the MMC material has a

Weibull modulus of 15 or greater.

33. The method of any one of Examples 28-32, wherein the MMC material has a

Weibull modulus of 20 or greater.

34. The method of any one of Examples 28-33, wherein the MMC material has a

Weibull modulus of 25 or greater.

35. The method of any one of Examples 28-34, wherein a linear extrapolation to a

1 in 10,000 probability of failure for the MMC material equates to 80 ksi or greater.

36. The method of any one of Examples 28-35, wherein a linear extrapolation to a

1 in 10,000 probability of failure for the MMC material equates to 140 ksi or greater.

37. The method of any one of Examples 28-36, wherein a linear extrapolation to a

1 in 10,000 probability of failure for the MMC material equates to 180 ksi or greater.

38. The method of any one of Examples 28-37, wherein the MMC material has a

transverse rupture strength of at least 140 ksi.

39. The method of any one of Examples 28-38, wherein the MMC material has a

transverse rupture strength of at least 450 ksi.

40. The method of any one of Examples 28-39, wherein the MMC material has a

transverse rupture strength of at least 700 ksi.

41. The method of any one of Examples 28-40, wherein the MMC material has an

erosive volume loss of 0.10 cm³ or less.

42. The method of any one of Examples 28-41, wherein the MMC material has an

erosive volume loss of 0.08 cm³ or less.

43. The method of any one of Examples 28-42, wherein the MMC material has an

erosive volume loss of 0.04 cm³ or less.

44. The method of any one of Examples 28-43, wherein the method comprises

forming the MMC material as part of a high strength drill bit, wherein the method further

comprises adding steel components into the mold, and wherein melting the binder material

comprises at least partially encompassing the steel component.

45. A high strength drill bit comprising: a metal matrix composite comprising fused tungsten carbide particles within a matrix, wherein the fused tungsten carbide particles have a spheroidal shape and a surface that is textured to have a grain boundary area fraction of at least 5.0%.

46. The drill bit of Example 45, wherein the fused tungsten carbide particles have

a grain boundary area fraction of at least 10.0%.

47. The drill bit of Examples 45 or 46, wherein the fused tungsten carbide

particles have a grain boundary area fraction of at least 12.0%.

48. The drill bit of any one of Examples 45-47, wherein the fused tungsten

carbide particles have a grain boundary area fraction of at least 20.0%.

49. The drill bit of any one of Examples 45-48, wherein the metal matrix

composite has a Weibull modulus of 15 or greater.

50. The drill bit of any one of Examples 45-49, wherein the metal matrix

composite has a Weibull modulus of 20 or greater.

51. The drill bit of any one of Examples 45-50, wherein the metal matrix

composite has a Weibull modulus of 25 or greater.

52. The drill bit of any one of Examples 45-51, wherein a linear extrapolation to a

1 in 10,000 probability of failure for the metal matrix composite equates to 80 ksi or greater.

53. The drill bit of any one of Examples 45-52, wherein a linear extrapolation to a

1 in 10,000 probability of failure for the metal matrix composite equates to 140 ksi or greater.

54. The drill bit of any one of Examples 45-53, wherein a linear extrapolation to a

1 in 10,000 probability of failure for the metal matrix composite equates to 180 ksi or greater.

55. The drill bit of any one of Examples 45-54, wherein the metal matrix

composite has a transverse rupture strength of at least 140 ksi.

56. The drill bit of any one of Examples 45-55, wherein the metal matrix

composite has a transverse rupture strength of at least 450 ksi.

57. The drill bit of any one of Examples 45-56, wherein the metal matrix

composite has a transverse rupture strength of at least 700 ksi.

58. The drill bit of any one of Examples 45-57, wherein the metal matrix composite has an erosive volume loss of 0.10 cm³ or less.

59. The drill bit of any one of Examples 45-58, wherein the metal matrix composite has an erosive volume loss of 0.08 cm³ or less.

60. The drill bit of any one of Examples 45-59, wherein the metal matrix composite has an erosive volume loss of 0.04 cm³ or less.

61. The powder blend of any one of Examples 1-12, wherein the powder blend is

configured to form a metal-matrix composite (MMC) including the fused tungsten carbide

particles embedded in a matrix formed of the alloy of Examples 1-12 of the Additional

Examples II.

62. The MMC material of any one of Examples 13-27, wherein the matrix is

formed of the alloy of Examples 65-76 of the Additional Examples II.

63. The method of any one of Examples 28-44, wherein the MMC comprises a

matrix formed of the alloy of Examples 65-76 of the Additional Examples II.

64. The drill bit of any one of Examples 45-60, wherein the metal matrix

composite comprises a matrix formed of the alloy of Examples 65-77 of the Additional

Examples II.

Additional Examples II

65. An alloy comprising:

manganese (Mn) at 5.6-10.4 weight percent (wt. %);

nickel (Ni) at 3.5-6.5 wt. %;

tin (Sn) at 1.4-4 wt. %; and

copper (Cu) exceeding 55 wt. % and up to a balance of the alloy,

wherein the alloy has a solidus temperature lower than a melting temperature

of Cu.

66. The alloy of Example 65, comprising 1.4-2.6 wt. % tin (Sn).

67. The alloy of Example 66, wherein the solidus temperature is lower than 1300

K.

68. The alloy of Example S 66 or 67, wherein the alloy forms a single phase solid

solution having a face-centered cubic (FCC) crystal structure from a solidus temperature

down to at least 400 K below the solidus temperature,.

69. The alloy of any one of Examples 65-68, wherein greater than 90 wt.% of the

alloy is a single phase solid solution with a face-centered cubic (FCC) crystal structure at

room temperature.

70. The alloy of any one of Examples 65-68, wherein the alloy further comprises

up to 2 wt. % of impurities.

71. The alloy of any one of Examples 65-70, wherein the elemental composition

does not include one or more of Si, B and Zn.

72. The alloy of any one of Examples 65-71, wherein the alloy has an electrical

conductivity higher than 2.5 MS/m.

73. The alloy of any one of Examples 65-72, wherein the alloy has a thermal

conductivity higher than 10 W/mK.

74. The alloy of any one of Examples 65-73, wherein the alloy forms a matrix of a

metal matrix composite (MMC) material, wherein the MMC material further comprises

tungsten carbide particles.

75. The alloy of any one of Examples 65-74, wherein the alloy forms a matrix of a

metal matrix composite (MMC) material, wherein the MMC material forms part of a drilling

component.

76. The alloy of any one of Examples 65-75, wherein the alloy forms a matrix of a

metal matrix composite (MMC) material, wherein the MMC material has a toughness greater

than 4,000 in*lbf.in³.

77. The alloy of any one of Examples 65-76, wherein the alloy is part of a

feedstock for forming a metal matrix composite (MMC) material, wherein the feedstock

further comprises tungsten carbide particles.

78. A metal matrix composite material comprising reinforcement particles

embedded in a copper-based matrix, wherein the copper-based matrix comprises greater than

55 wt. % copper (Cu) and greater than 1.4 wt. % tin (Sn).

79. The metal matrix composite material of Example 78, wherein the copper-

based matrix comprises:

1.4-4 wt. % tin (Sn);

5.6-10.4 wt. % manganese (Mn); and

3.5-6.5 wt. % nickel (Ni),

wherein the copper-based matrix has a solidus temperature lower than Cu.

80. The metal matrix composite material of Claim 79, wherein the copper-based

matrix comprises 1.4-2.6 wt. % tin (Sn).

81. The metal matrix composite material of any one of Examples 78-80, wherein

the solidus temperature of the copper-based matrix is lower than 1300 K.

82. The metal matrix composite material of any one of Examples 78-80, wherein

the copper-based matrix forms a single phase solid solution having a face-centered cubic

(FCC) crystal structure from a solidus temperature down to at least 400K below the solidus

temperature.

83. The metal matrix composite material of any one of Examples 78-82, wherein

greater than 90 wt.% of the copper-based matrix is a single-phase solid solution having a

face-centered cubic (FCC) crystal structure at room temperature.

84. The metal matrix composite material of any one of Examples 78-83, wherein

the copper-based matrix comprises 2 wt. % or less of impurities.

85. The metal matrix composite material of any one of Examples 78-84, wherein

the copper-based matrix does not include one or more of Si, B and Zn.

86. The metal matrix composite material of any one of Examples 78-85, wherein

the copper-based matrix has an electrical conductivity higher than 2.5 MS/m.

87. The metal matrix composite material of any one of Examples 78-86, wherein

the copper-based matrix has a thermal conductivity higher than 10 W/mK.

88. The metal matrix composite material of Example 78, wherein the reinforcement particles comprise tungsten carbide particles.

89. The metal matrix composite material of Example 88, wherein tungsten carbide

particles comprise 50-70 vol.% of the metal matrix composite material.

90. The metal matrix composite material of Examples 88 or 89 wherein the

tungsten carbide particles have an average particle size of 1-200 µm

91. The metal matrix composite material of any one of Examples 88-90, wherein

the tungsten carbide particles have a spheroidal shape having ratio, between a first length

along a major axis and a second length along a minor axis, of 1.20 or lower.

92. The metal matrix composite material of any one of Examples 78-91, wherein

the tungsten carbide particles have a surface that is textured to have a grain boundary area

fraction greater than 5.0%.

93. The metal matrix composite material of any one of Examples 78-92, wherein

the metal matrix composite material has a transverse rupture strength exceeding 175 ksi.

94. The metal matrix composite material of any one of Examples 78-93, wherein

the metal matrix composite material forms part of a drilling component.

95. A method of forming a metal-matrix composite (MMC) material, the method

comprising:

providing reinforcement particles and an alloy for forming a copper-based

matrix in a mold, wherein the alloy has an elemental composition comprising:

> 55 wt. % copper (Cu), and

> 1.4 wt. %; tin (Sn);

melting at least the alloy; and

solidifying the alloy to form the metal matrix composite material, wherein the

reinforcement particles are embedded in the copper-based matrix.

96. The method of Example 95, wherein the alloy comprises:

1.4-4 wt. % tin (Sn);

5.6-10.4 wt. % manganese (Mn); and

3.5-6.5 wt. % nickel (Ni),

wherein the alloy has a solidus temperature lower than a melting temperature

of Cu.

97. The method of Example 95, wherein the alloy comprises 1.4-2.6 wt. % tin

(Sn).

98. The method of any one of Examples 95-97, wherein melting the alloy

comprises heating the mold to a temperature lower than melting temperatures of one or more

of Cu, Mn and Ni..

99. The method of any one of Examples 95-98, wherein melting the alloy

comprises heating the mold to 1000-1200 °C.

100. The method of any one of Examples 95-99, further comprising infiltrating a

porous network formed by the reinforcement particles and wetting the surfaces of the

reinforcement particles with the melted alloy prior to solidifying the liquefied alloy.

101. The method of any one of Examples 95-100, wherein providing the reinforcement particles and an alloy comprises disposing the reinforcement particles below

the alloy such that gravity pulls melted alloy into a porous network formed by the

reinforcement particles.

102. The method of any one of Examples 95-101, wherein solidifying the alloy

comprises cooling the molten alloy to room temperature, and wherein greater than 90 wt.%

of the copper based matrix solidifies into a single phase solid solution having a face-centered

cubic (FCC) crystal structure.

103. The method of any one of Examples 95-102, wherein the alloy comprises 2

wt. % or less impurities, and the balance of the alloy is copper.

104. The method of any one of Examples 95-103, wherein the alloy is free of one

or more of Si, B and Zn.

105. The method of any one of Examples 95-104, wherein the copper based matrix

has an electrical conductivity higher than 2.5 MS/m.

106. The method of any one of Examples 95-106, wherein the copper-based matrix

has a thermal conductivity higher than 10 W/mK.

107. The method of any one of Examples 95-107, wherein the reinforcement

particles comprise tungsten carbide particles.

108. The method of Example 107, wherein 50-70 vol. % of the metal matrix

composite material comprises tungsten carbide particles.

109. The method of Examples 107 or 108, wherein the tungsten carbide particles

have an average particle size of 1-200 µm.

110. The method of any one of Examples 107-109, wherein the tungsten carbide

particles have a spheroidal shape having a ratio. between a first length along a major axis of

the particles and a second length along a minor axis of the particles, of 1.20 or lower.

111. The method of any one of Examples 107-110, wherein the tungsten carbide

particles have a surface that is textured to have a grain boundary area fraction greater than

5.0%. 112. The method of any one of Examples 95-111, wherein the metal matrix

composite material has a transverse rupture strength greater than 175 ksi.

113. The method of any one of Examples 95-112, further comprising forming the

metal matrix composite material into a drilling component.

114. The alloy of Examples 65-77, wherein the alloy is included as part of a

feedstock for forming a metal matrix composite (MMC) material, wherein the feedstock further comprises the powder blend according to Examples 1-12 of the Additional Examples

I.

115. The MMC material of Examples 78-94, wherein the reinforcement particles

comprise the powder blend according to Examples 1-12 of the Additional Examples I.

116. The method of Examples 95-113, wherein the reinforcement particles

comprise the powder blend according to Examples 1-12 of the Additional Examples I.

[0121] From the foregoing description, it will be appreciated that inventive

products and approaches for alloys are disclosed. While several components, techniques and

aspects have been described with a certain degree of particularity, it is manifest that many

changes can be made in the specific designs, constructions and methodology herein above

described without departing from the spirit and scope of this disclosure.

[0122] Certain features that are described in this disclosure in the context of

separate implementations can also be implemented in combination in a single implementation. Conversely, various features that are described in the context of a single

implementation can also be implemented in multiple implementations separately or in any

suitable subcombination. Moreover, although features may be described above as acting in

certain combinations, one or more features from a claimed combination can, in some cases,

be excised from the combination, and the combination may be claimed as any subcombination or variation of any subcombination.

[0123] Moreover, while methods may be depicted in the drawings or described in

the specification in a particular order, such methods need not be performed in the particular

order shown or in sequential order, and that all methods need not be performed, to achieve

desirable results. Other methods that are not depicted or described can be incorporated in the

example methods and processes. For example, one or more additional methods can be

performed before, after, simultaneously, or between any of the described methods. Further,

the methods may be rearranged or reordered in other implementations. Also, the separation

of various system components in the implementations described above should not be

understood as requiring such separation in all implementations, and it should be understood

that the described components and systems can generally be integrated together in a single product or packaged into multiple products. Additionally, other implementations are within the scope of this disclosure.

[0124] Conditional language, such as "can," "could," "might," or "may," unless

specifically stated otherwise, or otherwise understood within the context as used, is generally

intended to convey that certain embodiments include or do not include, certain features,

elements, and/or steps. Thus, such conditional language is not generally intended to imply

that features, elements, and/or steps are in any way required for one or more embodiments.

[0125] Conjunctive language such as the phrase "at least one of X, Y, and Z,"

unless specifically stated otherwise, is otherwise understood with the context as used in

general to convey that an item, term, etc. may be either X, Y, or Z. Thus, such conjunctive

language is not generally intended to imply that certain embodiments require the presence of

at least one of X, at least one of Y, and at least one of Z.

[0126] Language of degree used herein, such as the terms "approximately,"

"about," "generally," and "substantially" as used herein represent a value, amount, or

characteristic close to the stated value, amount, or characteristic that still performs a desired

function or achieves a desired result. For example, the terms "approximately", "about",

"generally," and "substantially" may refer to an amount that is within less than or equal to

10% of, within less than or equal to 5% of, within less than or equal to 1% of, within less

than or equal to 0.1% of, and within less than or equal to 0.01% of the stated amount. If the

stated amount is 0 (e.g., none, having no), the above recited ranges can be specific ranges,

and not within a particular % of the value. For example, within less than or equal to 10

wt./vol. % of, within less than or equal to 5 wt./vol. % of, within less than or equal to 1

wt./vol. % of, within less than or equal to 0.1 wt./vol. % of, and within less than or equal to

0.01 wt./vol. % of the stated amount.

[0127] Some embodiments have been described in connection with the accompanying drawings. The FIG.s are drawn to scale, but such scale should not be limiting,

since dimensions and proportions other than what are shown are contemplated and are within

the scope of the disclosed inventions. Distances, angles, etc. are merely illustrative and do

not necessarily bear an exact relationship to actual dimensions and layout of the devices

illustrated. Components can be added, removed, and/or rearranged. Further, the disclosure

herein of any particular feature, aspect, method, property, characteristic, quality, attribute, element, or the like in connection with various embodiments can be used in all other embodiments set forth herein. Additionally, it will be recognized that any methods described herein may be practiced using any device suitable for performing the recited steps.

[0128] While a number of embodiments and variations thereof have been

described in detail, other modifications and methods of using the same will be apparent to

those of skill in the art. Accordingly, it should be understood that various applications,

modifications, materials, and substitutions can be made of equivalents without departing

from the unique and inventive disclosure herein or the scope of the claims.

Claims (1)

1. WHAT IS CLAIMED IS:

   1. An alloy comprising: manganese (Mn) at 5.6-10.4 weight percent (wt. %); nickel (Ni) at 3.5-6.5 wt. %; tin (Sn) at 1.4-4 wt. %; 2022249075

   additional elements at a combined concentration less than 2%; and balance of copper (Cu), wherein the alloy has a solidus temperature lower than a melting temperature of Cu. 2. The alloy of Claim 1, wherein the alloy comprises tin (Sn) at 1.4-2.6 wt. %. 3. The alloy of Claim 1, wherein the solidus temperature is lower than 1300 K. 4. The alloy of Claim 1, wherein the alloy forms a single phase solid solution having a face-centered cubic (FCC) crystal structure from a solidus temperature down to at least 400 K below the solidus temperature. 5. The alloy of Claim 1, wherein greater than 90 wt.% of the alloy is a single phase solid solution with a face-centered cubic (FCC) crystal structure at room temperature. 6. The alloy of Claim 1, wherein the elemental composition does not include one or more of Si, B and Zn. 7. The alloy of any one of Claims 1-6, wherein the alloy has an electrical conductivity higher than 2.5 MS/m. 8. The alloy of any one of Claims 1-6, wherein the alloy has a thermal conductivity higher than 10 W/mK. 9. The alloy of any one of Claims 1-6, wherein the alloy forms a matrix of a metal matrix composite (MMC) material, wherein the MMC material further comprises tungsten carbide particles. 10. The alloy of any one of Claims 1-6, wherein the alloy forms a matrix of a metal matrix composite (MMC) material, wherein the MMC material forms part of a drilling component. 11. The alloy of any one of Claims 1-6, wherein the alloy forms a matrix of a metal matrix composite (MMC) material, wherein the MMC material has a toughness greater than 4,000 in*lbf.in3.

   12. The alloy of any one of Claims 1-6, wherein the alloy is part of a feedstock for forming a metal matrix composite (MMC) material, wherein the feedstock further comprises tungsten carbide particles. 13. A metal matrix composite material comprising reinforcement particles embedded in a copper-based matrix, wherein the copper-based matrix comprises 2022249075

   1.4-4 wt. % tin (Sn); 5.6-10.4 wt. % manganese (Mn); 3.5-6.5 wt. % nickel (Ni); additional elements at a combined concentration less than 2%; and a balance of copper (Cu), wherein the copper-based matrix has a solidus temperature lower than a melting temperature of Cu. 14. The metal matrix composite material of Claim 13, wherein the copper-based matrix comprises 1.4-2.6 wt. % tin (Sn). 15. The metal matrix composite material of Claim 13, wherein the copper-based matrix does not include one or more of Si, B and Zn. 16. The metal matrix composite material of any one of Claims 13-15, wherein the reinforcement particles comprise tungsten carbide particles. 17. The metal matrix composite material of Claim 16, wherein tungsten carbide particles comprise 50-70 vol.% of the metal matrix composite material. 18. The metal matrix composite material of any one of Claims 13-15, wherein the metal matrix composite material has a transverse rupture strength exceeding 175 ksi. 19. The metal matrix composite material of any one of Claims 13-15, wherein the metal matrix composite material forms part of a drilling component. 20. The metal matrix composite material of Claim 15, wherein the copper-based matrix does not include Zn.

   200 µm

   Figure 1

   100 um

   202 204 Figure 2

   100 pm

   306

   Figure 3

   Figure 4

   Figure 5

   TRS(ksi)

   60 80 100 120 140 160 188 200 220 240 260 280297

   20 10

   xx *

   8 MMCA 0.0 0.63

   * MMICE

   w * $ Probability (1/(1-F) In in -2.0 0.13

   # 0.018

   $ -6.0 0.0025

   y=13.76x-16028

   R'=0.85 R=09 -8.0 0.00034

   0.00012

   $ -10.0 0.000045

   10.8 11.0 11.4 11.6 11.8 122 12.6 120 124

   B In(TRS)

   604 Figure 6

   5 µm

   Figure 7

   5 µm

   Figure 8

   Figure 9

   Prior Art

   Figure 10

   Figure 11

   Figure 12

   20 pm

   Figure 13 of

   7

   Figure 14

   $000

   6000

   $400

   UHS+X17C

   W W ### Force(bt)

   300

   3400 UHS+Cu53

   1800

   1200

   600

   0

   4000

   4200 $ 0.008 0.012 0.018 0.024 0.03 0 0.008 8,642 3,648 5.084 0.08 0.008 0.022 0.00 Days (in)

   Figure 15