Permeation assembly

Abstract

A method for manufacturing an article comprising heat-treated tungsten carbide particles in a matrix of a bond alloy is provided. The method includes liquid metal infiltration. The tungsten carbide particles are preferably spherical, and the bonding alloy preferably contains copper. The tungsten carbide particles are preferably heat treated before or during the liquid metal infiltration process. Articles prepared by the method are also provided.

Description

TECHNICAL FIELD

[0001] The present subject matter relates to an assembly manufactured by infiltrating a bed of tungsten carbide powder with a metal alloy, thereby forming a metal matrix composite (MMC). BACKGROUND

[0002] In applications and industries requiring high wear resistance and / or high strength, there are several known methods for manufacturing assemblies. These methods include sintering, substrate cladding, and liquid metal infiltration.

[0003] Sintering: Sintered WC assemblies or cemented WC assemblies, most typically a blend of WC and Co or Ni, are used in various applications and industries requiring wear resistance and / or high strength. They are formed by a multi-step process that includes one or more of the following: 1. Powder preparation; 2. Blending; 3. Agglomeration; 4. Compaction; 5. Pre-sintering; 6. Shaping; 7. Sintering; 8. Hot isostatic pressing; 9. Finishing.

[0004] Preparation of the hard phase single tungsten carbide (WC) includes milling, sieving, and cleaning. Similar processes are performed on the soft phase materials (1) such as cobalt and nickel. Blending of the two materials (2) is achieved by mixing and fugitive binder such as wax after a period of time. The material is agglomerated into pellets or ready to press (RTP) powder by spray drying tower (3). The RTP is typically loaded into a die within a single axis press. Material loading is typically achieved by a robot. After pressing, the green state assembly is ejected from the press (6). After dewaxing and sintering (7) is high pressure sintering (8) to form the sintered part. Finally, the part is subjected to machining, roll grinding, and typically finishing (9) due to high material shrinkage.

[0005] Typically, the grain size of the single tungsten carbide is used when determining the material properties of the sintered composite. The single tungsten carbide has a local indentation resistance of about 1800 HV to 2000 HV that plastically deforms at room temperature. The typical grain size range is 0.0001 mm to 0.010 mm, most typically 0.001 mm to 0.004 mm. The strength and ductility of the composite is altered by the grain size of the single tungsten carbide and the proportion of the soft phase. The soft phase range can be in the range of 5 wt% to 35 wt%, most typically in the range of 6 wt% to 10 wt%. The overall wear resistance of the composite is limited by the hardness of the hard phase.

[0006] Substrate Coating: Various kinetic and thermal processes exist for forming wear-resistant surfaces on substrates. These include, but are not limited to: High-Voltage Oxygen Fuel (HVOF), Plasma Transfer Arc (PTA), Thermal Spray (TS), Metal Inert Gas (MIS), and Physical Vapor Deposition (PVD). The complexity of a typical manufacturing method can be understood in the following example. During drilling, a rotary guide tool is used to drill to the target location. Retractable pads on the tool's side provide steering control via mechanical engagement. A typical manufacturing route includes: 1. Processing of stainless steel substrates; 2. Position the diamond block within the recess; 3. Apply the cladding to the recesses and around the diamond block; 4. Grind hard surfaces; 5. Insert the carbide insert into the hole that forms the bushing and fulcrum.

[0007] The steel is machined into a complex geometry (1), including recesses and holes that allow the pad to pivot. A diamond or carbide block is attached to the recess (2). A cladding layer is applied to the block (3) and around it. The block (4) is then ground to a precise profile by removing excess cladding. During machining, a cemented carbide insert is applied to the hole to prevent wear on the steel (5) and to form a fulcrum.

[0008] The strength and ductility of a substrate are generally considered to be related to the applied stress. Substrate materials can include titanium, aluminum, and steel. Steel is typically used under heat-treated conditions and can have tensile yield stresses in the range of 100,000 psi to 200,000 psi. Alloying and different treatments result in increased strength. Most metallic substrates are also ductile and undergo plastic deformation before failure.

[0009] The cladding or coating utilizes hard phases such as tungsten carbide, boron nitride, and chromium carbide. Others include combinations of metals and oxides, borides, nitrides, and carbides. When such hard phases are added to the coating, their volume in the resulting surface-reinforced composite is limited by the application method. A range of approximately 40 vol% to 50 vol% is typically observed. This is relatively low compared to sintered composites and filled liquid metal-infiltrated composites, which range from approximately 65 vol% to 95 vol%.

[0010] Liquid metal infiltration: Liquid metal infiltration has been used for solid-state or backing substrate infiltration. The basic steps are: 1. Forming a powder bed; 2. Melt the adhesive and then bring it into direct or indirect contact with the powder bed; 3. Allow the adhesive sufficient time to wet and fill the voids in the powder bed through capillary action; 4. Cool to below the solidus line of the binder to form a metal matrix composite.

[0011] The powder bed (1) can be formed using a binder, and then pressed or placed using additive manufacturing to form a green body. This binder is lost, evaporated, or burned off during subsequent part heating. This binder can include polyethylene glycol, wax, paraffin, or cellulose-based materials. Typically, and more simply, a mold is formed and the mold is filled with powder. The powder can be metallic, ceramic, or cermet, and typically forms a hard phase within the resulting composite material. Where a combination of strength and wear resistance is required, the powder can be formed from pulverized tungsten carbide or spherical cast tungsten carbide, or a combination thereof. The mold itself and any internal mold fittings can be made of hard carbon, ceramic, sand, and steel. Mold components can be machined, formed by additive manufacturing, produced using a lost-wax process, or processed using a resin that hardens during moderate heating, or cured under a gas such as carbon dioxide. Internal or external components can be added within or near the powder bed to form a substrate.

[0012] The binder or penetrant (2) can form a molten bath, and the powder bed (1) is placed to contact or be completely immersed in the molten bath. In another technique commonly encountered in the manufacture of drill bodies, the penetrant is placed on top of the powder, and the entire part is heated, causing the binder to melt and form a metal matrix composite upon cooling.

[0013] In some cases, the powder may be placed in a mold, the penetrant placed on top, and positive pressure applied before, during, and / or after penetration (preferably throughout the process). In other cases, the powder may be consolidated by manual tapping or vibratory compaction to maximize the content of the hard phase.

[0014] When the penetrant is liquid, a complete penetration path is formed in component (3) based on the wettability of the hard phase with the penetrant, superheat, hydrostatic pressure, and melting time. The amount of time sufficient to provide complete penetration can be determined by a person skilled in the art using this instruction manual as guidance and will depend on the materials used and the articles being manufactured. For example, a penetration time of 15 minutes may be sufficient for test specimens and small articles. Larger articles, such as machine parts, typically require a longer time, such as about an hour. Cooling (4) can be accomplished in still air, by a fan, or by directional cooling via a water jet. This results in a metallic matrix composite material after solidification.

[0015] In another example, a component is formed using liquid metal infiltration. The bearing used in a downhole motor is formed using a steel mold. An annular gap is formed between two components. This gap is filled with metal powder and compacted. An adhesive is placed on the powder, and the component is heated by an induction coil or similar device. Upon cooling, a metal matrix composite is formed.

[0016] Figure 1 A known configuration for a liquid metal permeation process is shown. A porous medium 101 is positioned to contact either a liquid 102 or a solid permeant 103. The porous medium may be partially submerged ( Figure 1 a), or completely immersed in liquid penetrant ( Figure 1 b), or a solid penetrant can be placed in contact with a porous medium ( Figure 1 c).

[0017] Compared to methods using multi-step cementation sintering operations, metal matrix composites formed by liquid metal infiltration offer a very simple manufacturing method to form freestanding monolithic or backed substrate monolithic materials. Conventional metal matrix composites generally cannot compete with sintered cemented tungsten carbide and substrate-coated components because the combination of properties of metal matrix composites is compromised and is generally poor. These deficiencies include, but are not limited to: strength, ductility, plasticity, abrasion resistance, fracture toughness, and thermal shock resistance. Typical metal matrix composites exhibit very low ductility and are classified as brittle materials. During testing, little or no plastic deformation is encountered, and linear elastic behavior is observed, followed by transient failure. When tested in bending, the strength is typically limited to a maximum of 160,000 psi. Reliability is limited by the statistical distribution of defects and the overall strength of the composite determined using Weibull statistics. Typically, a Weibull modulus of around 20 is achieved. This generally limits their use in many engineering applications. Liquid metal infiltration is typically carried out at temperatures below 1180°C.

[0018] The mechanical properties of metal matrix composites are generally inferior to those of typical coated substrates. The surface abrasion resistance of the substrate may not meet the requirements of its operating environment; for example, unsatisfactory corrosion resistance, abrasion resistance, and erosion resistance. Therefore, coatings or cladding are required.

[0019] Although the method of manufacturing by liquid metal infiltration is well known, its application is usually limited to drill bits and bearings.

[0020] The use of simple methods for liquid metal infiltration to form solid or backed substrate components with strength and ductility would be advantageous, as it would provide a surprisingly attractive alternative to conventional engineering substrates such as steel. The combination of wear resistance, competing with coated or encapsulated substrates and sintered tungsten carbide components, opens doors to new and unexpected applications for liquid metal infiltrated composites. Summary of the Invention

[0021] A cast tungsten carbide powder is provided, comprising particles having a grain interface fraction of 20% to 50% and an average aspect ratio of less than 1.3. A heat-treated cast tungsten carbide powder is also provided, prepared by heating a tungsten carbide powder, such as those described above, to a temperature of 1000°C to 1250°C, preferably 1100°C to 1250°C or 1190°C to 1250°C, for a period of 0.5 hours to 50 hours in a vacuum or non-reactive atmosphere prior to liquid metal infiltration to form a metal matrix composite. This transformation results in the formation of metallic tungsten within the cast tungsten carbide particles.

[0022] Alternatively, a transformation and performance improvement of tungsten carbide powder is provided, the tungsten carbide powder comprising particulates having a particle-to-grain interface integral of 20% to 50% and an average aspect ratio of less than 1.3, and a carbon content of 3.0% to 4.5% by weight. A transformation is provided during liquid metal infiltration when the tungsten carbide powder is contacted with liquid metal at a temperature of 1000°C to 1250°C, preferably 1190°C to 1250°C, for a period of 0.5 hours to 50 hours.

[0023] Before or during liquid metal infiltration, the transformation of the properties of cast tungsten carbide involves the formation of a tungsten metallic phase within the cast tungsten carbide particles at 1 wt% to 50 wt%, preferably 5 wt% to 50 wt%, and most preferably 10 wt% to 50 wt%. The particles may or may not contain a half-carbide (W₂C) phase. Compared to those that are not transformed, the resulting particles exhibit increased toughness, thermal conductivity, and thermal shock resistance. These desired properties are then transferred to the resulting metal matrix composite.

[0024] Some specific preferred embodiments include, for example, casting tungsten carbide powder comprising a tungsten carbide (monocarbide) phase; and a metallic tungsten phase which may or may not contain a half-carbide (W2C) phase.

[0025] In the embodiments, the powder contains a tungsten phase, the fraction of which is not less than 1% to 10% by weight, preferably not less than 11% to 20%, and most preferably not less than 21% to 50%.

[0026] The carbon content of the tungsten carbide powder (which may be heat-treated tungsten carbide powder) is preferably from 3.0% to 4.5% by weight.

[0027] Compositions comprising tungsten carbide powder and an alloy comprising 50% to 85% copper by weight are also provided.

[0028] A method for manufacturing a metal matrix composite article is also provided, the method comprising: obtaining cast tungsten carbide powder containing transformed cast tungsten carbide powder; heating the cast tungsten carbide powder to a certain temperature and sustaining it for a sufficient time in the presence of a binder alloy, causing the binder alloy to melt and permeate the cast tungsten carbide powder to form a permeated article; and obtaining the metal matrix composite article by cooling the permeated article to solidify the binder alloy, wherein the heat-treated tungsten carbide is prepared by heating raw tungsten carbide powder with an aspect ratio less than 1.3 and needle-like structures on its surface to a temperature of 1000°C to 1250°C, preferably 1100°C to 1250°C or 1190°C to 1250°C, in a vacuum or non-reactive atmosphere or in air for a period of 0.5 hours to 50 hours; the cast tungsten carbide powder contains at least 10% by weight of transformed heat-treated tungsten carbide powder based on the total carbides in the tungsten carbide powder; and the binder alloy contains 50% by weight to 85% by weight of copper.

[0029] Alternatively, during the liquid metal process, casting tungsten carbide particles can be converted into up to 50% by weight of tungsten by ensuring that the liquid phase is in contact with these particles at 1000°C to 1250°C (preferably 1190°C to 1250°C) for 0.5 hours to 50 hours.

[0030] In this manufacturing method, the heat-treated tungsten carbide powder preferably comprises particulates with a grain interface integral of 20% to 50% and an average aspect ratio of less than 1.3. In this manufacturing method, the heat-treated tungsten carbide powder preferably has a surface morphology including needle-like structures with an aspect ratio of less than 1.3. In this manufacturing method, the heat-treated tungsten carbide powder preferably has a surface morphology including needle-like structures with an aspect ratio in the range of 1 to 1.3.

[0031] Metal matrix composite articles prepared by this manufacturing method are also provided.

[0032] Also provided is a metal matrix composite article comprising cast tungsten carbide particles in an alloy matrix, wherein the cast tungsten carbide particles comprise 10% to 100% by weight of heat-treated tungsten carbide particles based on the total weight of the tungsten carbide particles, the heat-treated tungsten carbide particles being heated to 1000°C to 1250°C in a vacuum or non-reactive atmosphere, preferably at 1100°C to 1250°C or 1190°C to 1250°C for a period of 0.5 hours to 50 hours, the tungsten carbide particles or heat-treated tungsten particles having an aspect ratio of 1 to 1.3, and the alloy matrix comprising 50% to 85% by weight of copper.

[0033] It also provides in-situ heat treatment of cast tungsten carbide to form MMC during the liquid metal infiltration process and when in contact with liquid metal, wherein the infiltration temperature is between 1000°C and 1250°C, preferably between 1190°C and 1250°C, and the infiltration time is between 0.5 hours and 50 hours.

[0034] When measured according to ASTM G65, metal matrix composite articles preferably exhibit a thickness of 6 mm. 3 Or even less abrasion resistance. When measured according to ASTM B611, the metal matrix composite article preferably exhibits a volume loss of 0.8 cc or less. The metal matrix composite article preferably exhibits a Charpy impact toughness of at least 6.75 J.

[0035] In some aspects, the metal matrix composite article comprises tungsten carbide particles with a D50 of 1 μm to 10 μm and a TRS greater than or equal to 360 ksi. In some aspects, the metal matrix composite article comprises tungsten carbide particles with a D50 of 11 μm to 20 μm and a TRS greater than or equal to 280 ksi. In some aspects, the metal matrix composite article comprises tungsten carbide particles with a D50 of 21 μm to 40 μm and a TRS greater than or equal to 230 ksi. In some aspects, the metal matrix composite article comprises tungsten carbide particles with a D50 of 41 μm to 60 μm and a TRS greater than or equal to 180 ksi. In some aspects, the metal matrix composite article comprises tungsten carbide particles with a D50 of 61 μm to 80 μm and a TRS greater than or equal to 160 ksi. In some aspects, the metal matrix composite article comprises tungsten carbide particles with a D50 of 81 μm to 100 μm and a TRS greater than or equal to 140 ksi. In some aspects, the metal matrix composite article comprises tungsten carbide particles with a D50 of 111 μm to 200 μm and a TRS greater than or equal to 100 ksi. In some aspects, the metal matrix composite article comprises tungsten carbide particles with a D50 of 201 μm to 500 μm and a TRS greater than or equal to 80 ksi. In some aspects, the metal matrix composite article comprises tungsten carbide particles with a D50 of 501 μm to 1000 μm and a TRS greater than or equal to 60 ksi. In some aspects, the metal matrix composite article comprises tungsten carbide particles with a D50 of 1001 μm to 2000 μm and a TRS greater than or equal to 50 ksi.

[0036] In some implementations, metal matrix composite articles contain different composite materials in different regions of the component to provide the required performance during use. Attached Figure Description

[0037] Figure 1 A known configuration of the liquid metal permeation process is shown. The porous medium can be partially immersed in the liquid permeating agent.Figure 1 a) completely submerged in liquid penetrant ( Figure 1 b), or a solid penetrant can be placed in contact with a porous medium ( Figure 1 c).

[0038] Figure 2 The component covered by the substrate is shown. Figure 2 a and adhesive WC components Figure 2 In the exemplary component made of b, in the substrate-covered component, a portion of the component is covered with a WC layer 202 onto a steel component 203, and in the bonded WC component, the entire component is made of bonded WC.

[0039] Figure 3 An example diagram of a bottle opener with two composite materials is shown.

[0040] Figure 4 It is an SEM image of a conventional metal powder with angular particles.

[0041] Figure 5 These are optical micrographs of conventional MMC prepared using angular particles.

[0042] Figure 6 These are optical micrographs of MMC prepared using spherical particles.

[0043] Figure 7 This is a SEM image of a typical spherical carbide.

[0044] Figure 8 It is a SEM image of textured spherical carbides according to this disclosure.

[0045] Figure 9 yes Figure 7 A binary image.

[0046] Figure 10 yes Figure 8 A binary image.

[0047] Figure 11 Photographs of Vickers hardness indentations on WC particles in MMC products are provided, where the WC powder was not heat-treated. Figure 11 a to Figure 11 d), and the WC powder therein has been heat-treated ( Figure 11 e to Figure 11 h).

[0048] Figure 12 The slide distance comparison is shown between medium-sized cemented tungsten carbide with 10% cobalt and a penetrating assembly with heat-treated spherical cast tungsten carbide after ASTM B611 wear testing. Detailed Implementation

[0049] This document discloses embodiments of infiltration components that meet or exceed the performance properties of sintered WC components and cladding substrates. Compared to typical labor-intensive methods used to manufacture sintered WC components and cladding substrates, this disclosure provides an infiltration process. A series of efforts are described that transform a lower-cost infiltration process (currently reserved for drill bodies and bearings) into performance schemes that match and exceed the properties of sintered components, cladding substrates, and the substrates themselves.

[0050] This invention can be applied to a variety of applications and industries. Figure 2 Two non-limiting illustrative examples of substrate-coated components are provided. Figure 2 In b, a portion of the component is a WC layer 202 that covers part 203 (e.g., steel). Figure 2 b shows an assembly made entirely of bonded WC. Figure 2 An exemplary substrate-covered assembly of a is a retractable pad used in rotary guide tools in the oil and gas industry. Figure 2 The exemplary bonded WC assembly of b is also used in fracturing valve seats in the oil and gas industry. The permeation assemblies described herein can be used to manufacture two exemplary assemblies that replace current manufacturing methods. It should be understood that for components coated with a WC-containing layer (e.g., Figure 2 (a's expandable pad), the permeable component can be used to manufacture the entire component and not just the cladding, thereby also replacing all or part of the component, such as the steel part.

[0051] In some embodiments of the invention, certain common processes for manufacturing bonded WC are preferably avoided. In some embodiments, it is preferred to manufacture the infiltration module without sintering and / or hot isostatic pressing. In some embodiments, it is preferred to manufacture the infiltration module without any welding processes (such as MIG, TIG open arc welding, PTA, and / or laser cladding). In some embodiments, it is preferred to manufacture the infiltration module without any thermal spraying processes (such as TWAS, HVOF, and / or plasma spraying). In some embodiments, it is preferred to manufacture the infiltration module without any vapor deposition processes (such as CVD and PVD).

[0052] In some embodiments, the component is used in wear-resistant parts and is characterized by high wear resistance quantified by ASTM G65 dry sand abrasion test and / or ASTM B611 high stress abrasion test. In some embodiments, the component has an ASTM G65 volume loss of 6 mm. 3 Or lower, 5mm 3 Or lower, 4mm 3 Or lower, or 3mm 3 Or lower. The ASTM G65 volume loss of the component is typically 0 mm. 3or higher, 1mm 3 or higher, 2mm 3 Or higher, or 3mm 3 Or higher. Also includes the range formed by these values ​​(including or excluding endpoints), such as 0mm. 3 Up to 6mm 3 0mm 3 up to 5mm 3 0mm 3 Up to 4mm 3 0mm 3 Up to 3mm 3 1mm 3 Up to 6mm 3 2mm 3 Up to 6mm 3 3mm 3 Up to 6mm 3 and 1mm 3 Up to 5mm 3 ASTM G65 volume loss.

[0053] Volumetric loss is measured according to the high-stress wear test according to ASTM B611, typically in cubic centimeters (cc). ASTM B611 volumetric loss is preferably less than or equal to 0.8 cc, 0.75 cc, or 0.65 cc. ASTM B611 volumetric loss is preferably greater than or equal to 0 cc, 0.05 cc, 0.1 cc, 0.2 cc, 0.4 cc, or 0.45 cc. Ranges formed by these values ​​(including or excluding endpoints) are also included, such as less than 0.8 cc, 0.8 cc or less, less than 0.75 cc, 0.75 cc or less, less than 0.65 cc, 0.65 cc or less, 0.8 cc to 0.05 cc, 0.75 cc to 0.1 cc, 0.65 cc to 0.1 cc, and 0.05 cc to less than 0.8 cc.

[0054] In this disclosure, the size of the spherical cast tungsten particles used in the components can range from 1 μm to 2000 μm, or from about 1 μm to 200 μm. Variations in the size of the spherical cast tungsten particles can affect the transverse breaking strength (TRS) of the final infiltrated MMC. Transverse breaking strength (TRS) is measured by applying a central force to a cylindrical rod. The tensile stress generated under the applied force increases until failure. The failure stress is calculated from the applied force and the geometry of the test rod. This technique is described in detail in ASTM B406 and is used for small cubic specimens, which are commonly used to measure the TRS of cemented tungsten carbide. For liquid metal infiltrated components, internal standards using cylinders are typically applied.

[0055] Determining powder particle size distribution is entirely within the capabilities of those skilled in the art, and such skill would be familiar with the equipment and methods used to do so. A preferred method involves the use of laser scattering, such as the MicroTrac apparatus according to ASTM B822, the entire contents of which are incorporated herein by reference. Different measures of particle size can be determined from various points on the curve obtained by this method. Three such points include: -D10 or 10th percentile particle size (μm). -D50 or average particle size (μm), and -D90 or 90th percentile particle size (μm).

[0056] Unless otherwise stated, the particle size referred to herein is generally the average particle size D50. In general, the choice of tungsten carbide powder particle size affects the performance of MMC articles made from that powder. For example, as is known in the art, all other things being equal, there is an inverse relationship between carbide powder particle size and component strength. Therefore, components made from finer (smaller D50) carbide powder tend to exhibit greater strength than those made from coarser (larger D50) carbide powder. On the other hand, smaller particle size can lead to reduced toughness, as larger grains are tougher in cemented tungsten carbide. The D50 of the selected tungsten carbide particles will generally depend on the specific application intended and can be selected as needed by those skilled in the art. This literally means that one size is not suitable for all situations.

[0057] Therefore, tungsten carbide particles are available in a wide range of sizes and ranges for various applications. Some tungsten carbide particle sizes include 1 μm, 5 μm, 10 μm, 15 μm, 20 μm, 30 μm, 40 μm, 50 μm, 60 μm, 70 μm, 80 μm, 90 μm, 100 μm, 120 μm, 140 μm, 160 μm, 180 μm, 200 μm, 250 μm, 500 μm, 1000 μm, and 2000 μm, all of which can be increased or decreased by 1 μm. Also considered are ranges formed by any two of these values ​​(including and excluding the endpoints), such as 1 μm to 10 μm, 10 μm or 11 μm to 20 μm, 11 μm to 20 μm, 20 μm to 40 μm, 21 μm to 39 μm, 40 μm to 60 μm, 60 μm to 80 μm, 80 μm to 100 μm, and 100 μm to 200 μm, 200 μm to 500 μm, 500 μm to 1000 μm, and 1000 μm to 2000 μm.

[0058] In some embodiments, components made from spherical cast tungsten carbide particles with an average particle size (D50) of 1 μm to 10 μm have a TRS greater than or equal to 360 ksi (or about 360 ksi), greater than or equal to 530 ksi (or about 530 ksi), or greater than or equal to 700 ksi (or about 700 ksi). Higher TRS have also been considered. In practice, TRS is typically less than 1000 ksi.

[0059] In some embodiments, components made from spherical cast tungsten carbide particles with an average particle size (D50) of 11 μm to 20 μm have a TRS greater than or equal to 280 ksi (or about 280 ksi), greater than or equal to 365 ksi (or about 365 ksi), or greater than or equal to 450 ksi (or about 450 ksi). Higher TRS have also been considered. In practice, TRS is typically less than 700 ksi.

[0060] In some embodiments, components made from spherical cast tungsten carbide particles with an average particle size (D50) of 21 μm to 40 μm have a TRS greater than or equal to 230 ksi (or about 230 ksi), greater than or equal to 260 ksi (or about 260 ksi), or greater than or equal to 290 ksi (or about 290 ksi). Higher TRS have also been considered. In practice, TRS is typically less than 450 ksi.

[0061] In some embodiments, components made from spherical cast tungsten carbide particles with an average particle size (D50) of 41 μm to 60 μm have a TRS greater than or equal to 180 ksi (or about 180 ksi), greater than or equal to 200 ksi (or about 200 ksi), or greater than or equal to 220 ksi (or about 220 ksi). Higher TRS have also been considered. In practice, TRS is typically less than 350 ksi.

[0062] In some embodiments, components made from spherical cast tungsten carbide particles with an average particle size (D50) of 61 μm to 80 μm have a TRS greater than or equal to 160 ksi (or about 160 ksi), greater than or equal to 170 ksi (or about 170 ksi), or greater than or equal to 180 ksi (or about 180 ksi). Higher TRS have also been considered. In practice, TRS is typically less than 300 ksi.

[0063] In some embodiments, components made from spherical cast tungsten carbide particles with an average particle size (D50) of 81 μm to 100 μm have a TRS greater than or equal to 140 ksi (or about 140 ksi), greater than or equal to 150 ksi (or about 150 ksi), or greater than or equal to 160 ksi (or about 160 ksi). Higher TRS have also been considered. In practice, TRS is typically less than 250 ksi.

[0064] In some embodiments, components made from spherical cast tungsten carbide particles with an average particle size (D50) of 101 μm to 200 μm have a TRS greater than or equal to 100 ksi (or about 100 ksi), greater than or equal to 120 ksi (or about 120 ksi), or greater than or equal to 140 ksi (or about 140 ksi). Higher TRS have also been considered. In practice, TRS is typically less than 200 ksi.

[0065] In some embodiments, components made from spherical cast tungsten carbide particles with an average particle size (D50) of 201 μm to 500 μm have a TRS greater than or equal to 80 ksi (or about 80 ksi), greater than or equal to 90 ksi (or about 90 ksi), or greater than or equal to 95 ksi (or about 95 ksi). Higher TRS have also been considered. In practice, TRS is typically less than 100 ksi.

[0066] In some embodiments, components made from spherical cast tungsten carbide particles with an average particle size (D50) of 501 μm to 1000 μm have a TRS greater than or equal to 60 ksi (or about 60 ksi), greater than or equal to 70 ksi (or about 70 ksi), or greater than or equal to 75 ksi (or about 75 ksi). Higher TRS have also been considered. In practice, TRS is typically less than 80 ksi.

[0067] In some implementations, components made from spherical cast tungsten carbide particles with an average particle size (D50) of 1001 μm to 2000 μm have a TRS greater than or equal to 50 ksi (or about 50 ksi) and greater than or equal to 55 ksi (or about 55 ksi). Higher TRS have also been considered. In practice, TRS is typically less than 60 ksi.

[0068] In some embodiments, the novel metal matrix composite is characterized by high toughness. The Charpy impact test is a typical method for evaluating material toughness, and unnotched Charpy impact specimens are used to quantify the toughness of the disclosed components. In some embodiments, the Charpy impact toughness exceeds 5.0 ft-lbf (or 6.75 J or 6.8 J), in preferred embodiments, it exceeds 6.0 ft-lbf (or 8 J or 8.1 J), in more preferred embodiments, it exceeds 8.0 ft-lbf (or 10.75 J or 10.8 J), and more preferably, the component's toughness exceeds 9.0 ft-lbf (or 12 J or 12.2 J), 10.0 ft-lbf (or 13.6 J or 14 J), or 11.0 ft-lbf (or 14.9 J or 15 J). While there is no preferred upper limit for toughness, in practice, Charpy impact toughness is typically less than 20.0 ft-lbf (or 27 J or 27.1 J). Charpy impact toughness can be measured according to ASTM E23 without a V-notch or by another suitable method.

[0069] Enhanced toughness is a key performance property that makes the disclosed components suitable for applications more typically used in bonded tungsten carbide components. This enhanced toughness, combined with strength, is not common in typical components manufactured via a percolation process. For example, industrially dominant percolation components used in the drill bit industry, comprising Cu53 copper binder and angular WC binder, exhibit a toughness of 3.3 ft-lbf (or 4.47 J or 4.5 J) in a comparable unnotched Charpy impact test. The use of spherical WC particles does indeed enhance toughness, up to 5.9 ft-lbf or 8.0 J. Using the novel binder described in this disclosure in combination with spherical textured carbides, toughness is further increased to 9.2 ft-lbf or 12.5 J. When the spherical cast tungsten carbide particles are heat-treated between 1000°C and 1250°C, and preferably between 1190°C and 1250°C, for 0.5 to 50 hours, toughness again increases to 13.7 ft-lbf or 18.6 J. Therefore, the component technology described herein offers a 315% increase in toughness compared to currently used Cu53 copper-based binders and angular WC technologies. This dramatic increase enables the disclosed technology to be used in structural components that are typically reserved for bonding tungsten carbide components.

[0070] In some embodiments, the component can be described by the composition used to prepare the final component. During the infiltration process, carbide powder is placed in a mold of a suitable material (typically graphite). More typically, after the carbide is added to the mold, the mold is typically vibrated to allow the carbide to settle. A metallic alloy (typically copper-based) is placed on top of the carbide powder. The component is introduced into a furnace, allowing the copper to melt and infiltrate into the free space within the carbide powder. Upon cooling, the component becomes a solid assembly of copper alloy and carbide powder firmly bonded together. In one embodiment of the invention, the carbide powder is tungsten carbide (WC) powder. In a preferred embodiment, the carbide powder has a textured surface, as opposed to a smooth surface. In another preferred embodiment, the carbide powder is spherical. In a more preferred embodiment, the carbide powder is spherical WC with a textured surface. In other preferred embodiments of the invention, the tungsten carbide is heat-treated prior to the infiltration process. In another preferred embodiment of the invention, tungsten carbide is subjected to in-situ heat treatment during the liquid metal infiltration process to form MMC, wherein the infiltration temperature is between 1000°C and 1250°C, preferably between 1190°C and 1250°C, and the infiltration time is between 0.5 hours and 50 hours. In another embodiment, a high-copper binder alloy is used.

[0071] In another embodiment, inserts are used to form the desired final shape of the component. In some embodiments, these inserts are 3D printed. These inserts can be ceramic (such as alumina or silicon carbide), sand (such as quartz or silicon beads), or plastic. In some embodiments, these 3D-printed sand inserts are placed within a graphite container, which may include a base, sides, and a lid. The sand mold or ceramic mold and graphite assembly also includes a porous briquette and a binder material, and the assembly can be heated to allow a permeation process to occur, thereby forming the MMC composite material into the desired shape.

[0072] In another embodiment, different materials are used in different locations within the mold and the resulting part. For example, finer-grained materials provide strength, while coarser-grained materials improve wear resistance. Figure 3 An example diagram of a bottle opener featuring two composite materials is shown. Figure 3In this embodiment, composite material A exhibits high abrasion resistance, while composite material B demonstrates high strength. In some embodiments, the infiltration assembly comprises a region with high strength and another region with high abrasion resistance. The high-strength region has a D50 of 1 μm to 100 μm and a TRS of 140 ksi to 1000 ksi, and an ASTM B611 volume loss of 0.65 cc to 0.80 cc. The high-abrasion-resistant region has an ASTM B611 volume loss of 0.10 cc to 0.65 cc, a D50 of 100 μm to 2000 μm, and a TRS of 50 ksi to 140 ksi. In some other embodiments, the infiltration assembly comprises a region containing untreated tungsten carbide and another region containing 10% to 100% by weight of the total weight of tungsten carbide in that region, which is heat-treated tungsten carbide. In yet another embodiment, the infiltration assembly comprises several regions with different fractions of heat-treated tungsten carbide. For example, in one region of the infiltration assembly, the region contains 40% by weight of heat-treated tungsten carbide. In another region of the permeation module, this region contains 100% by weight of heat-treated tungsten carbide. In yet another region of the permeation module, this region contains 0% by weight of heat-treated tungsten carbide.

[0073] Carbide powder morphology : In some embodiments of the invention, the carbides of the components have a spherical morphology. The spherical carbides used according to this disclosure can be prepared from carbide powder, such as the carbide powder disclosed in WO 2021 / 173515 (the entire contents of which are incorporated herein).

[0074] These spherical or substantially spherical fused tungsten carbide particles can typically be made from regular fused tungsten carbide powder or a mixture of tungsten, monotungsten carbide, and / or carbon. In some embodiments, the spherical or substantially spherical fused tungsten carbide particles may have a composition of 3.7 wt% to 4.2 wt% (or about 3.7 wt% to 4.2 wt%) of combined carbon, with tungsten as the balance. The particles can be prepared by a variety of methods. In some methods, a mixture of tungsten powder blended with monotungsten carbide and carbon powder is first melted. The molten mixture is then atomized by rotary atomization or ultra-high temperature melting and atomization. These methods spheroidize the molten tungsten carbide into spherical or substantially spherical fused tungsten carbide particles due to surface tension during rapid solidification. Other methods may be based on modification of conventional fused tungsten carbide powder. Plasma spraying, induction melting, or resistance furnace melting are applied during the spheroidization process to obtain fine spherical or substantially spherical fused tungsten carbide particles.

[0075] As described herein, "sphericity" can be defined by the aspect ratio of spherical or substantially spherical particles. The aspect ratio can be the ratio of a first length along the major axis to a second length along the minor axis, or the ratio of the longest axis length to the shortest axis length. For example, a "perfectly" spherical particle would have an aspect ratio of exactly 1.0. On the other hand, "angular" particles (such as those discussed above in the art) have an aspect ratio of at least 1.30.

[0076] In embodiments of this disclosure, the aspect ratio of the spherical or substantially spherical fused tungsten carbide particles disclosed herein is 1.30 (or about 1.30) or lower. In some embodiments, the aspect ratio of the spherical fused tungsten carbide is 1.20 (or about 1.20) or lower. In some embodiments, the aspect ratio of the spherical fused tungsten carbide is 1.10 (or about 1.10) or lower. In some embodiments, the aspect ratio of the spherical fused tungsten carbide is 1.05 (or about 1.05) or lower. The aspect ratio may also have values ​​within a range defined by any two of these values. The aspect ratio disclosed herein may represent the average aspect ratio of a plurality of fused tungsten carbide particles. In some embodiments, each particle may have the aspect ratio disclosed herein. Some upper limits for the aspect ratio include 1.3, 1.2, 1.1, and 1.05. Lower limits include 1.2, 1.1, and 1.05, wherein the understood minimum value is 1. Also consider the range formed by any two of these values ​​(including and excluding the endpoints), such as less than 1.3, less than or equal to 1.3, less than 1.2, 1.05 to 1.3, 1 to 1.05 (or equivalently, "at most 1.05" or "1.05 or less").

[0077] Aspect ratios can be determined by any suitable method by a person of ordinary skill. For example, the aspect ratio can be determined from visual or computer-aided analysis of micrographs of tungsten carbide powder.

[0078] The specific density of this spherical or substantially spherical fused tungsten carbide powder can be approximately 16.5 g / cm³. 3 The microhardness is advantageously in the range of 2,700 HV to 3,300 HV (or about 2,700 HV to about 3,300 HV). These properties can be attributed to the particle shape and internal microstructure produced by the above-described spheroidization process. In other embodiments, lower hardness tungsten carbide with a hardness range of 1,900 HV to 2,300 HV is used; the reduction in hardness is due to heat treatment. Generally, for particles of comparable size and fraction, MMC containing spherical or substantially spherical fused tungsten carbide particles is more wear-resistant than MMC containing angular fused tungsten carbide particles. Below, various microstructural differences between conventional angular tungsten carbide particles and MMC formed therefrom, and spherical or substantially spherical tungsten carbide particles and MMC formed therefrom according to embodiments, are described.

[0079] Figure 4 This is a scanning electron microscope (SEM) image of a conventional metal powder. As shown in the image, the powder has angles.

[0080] Figure 5 These are optical micrographs of conventional MMC prepared using known metallographic techniques. As shown in the figure, the MMC comprises a soft phase 501 and a granular phase 502 (composed of components similar to...). Figure 4 The powder shown is formed at the interface 503 between the particles and the soft phase. The soft phase can be formed from a matrix material that is first melted and then cooled. Therefore, Figure 5 The MMC consists of two main phases: a soft phase 501 formed by the infiltration of liquid metal through a particulate phase 502.

[0081] The particulate phase may include metal carbides, borides, or oxides. For example, a specific phase may include tungsten carbide, including: single tungsten carbide, fused tungsten carbide, and / or cemented tungsten carbide. Tungsten carbide particles are typically angular, such as... Figure 4 As shown, there is an interface between the soft phase and the particulate phase. As described herein, the inventors unexpectedly discovered that all three can contribute to the strength and abrasion resistance of MMC.

[0082] Figure 6 An optical micrograph of a metal matrix composite (MMC) 20 prepared using spherical or substantially spherical carbide particles according to an embodiment is shown. As shown, MMC 20 comprises spherical or substantially spherical fused tungsten carbide particles 4 and a soft phase 5, which are combined to form the metal matrix composite (MMC) 20. MMC 20 further comprises a spherical or substantially spherical fused tungsten carbide-soft phase interface 6.

[0083] Interface 6 includes a metallic or metallurgical bond formed between tungsten carbide particles 4 and the soft phase 5. It should be understood that the metallurgical bond disclosed herein may include diffused atomic and / or atomic interactions, and may include chemical bonds formed between atoms of particle 4 and atoms of the soft phase. Metallurgical bonding is not merely mechanical bonding. Under these conditions, the components may be “wetted” by a metallic binder, or mutually “wetted” with a metallic binder.

[0084] Carbide particle surface morphology : In some embodiments of the invention, the carbides of the components have a unique textured surface morphology.

[0085] In this disclosure, the surface morphology of spherical or substantially spherical fused tungsten carbide particles forming powder is examined in detail. This novel surface state of spherical or substantially spherical fused tungsten carbide has a textured surface. The inventors have discovered that this texture can increase the available surface area at the interface 6 between the soft phase 5 and the spherical or substantially spherical fused tungsten carbide particles 4, such as... Figure 6 As shown.

[0086] Figure 7 The surface morphology of tungsten particles in a conventional MMC is shown. As illustrated, the microstructure exhibits the "soccer ball-like" morphology characteristic of conventional fused tungsten carbide particles. The surface is relatively smooth, resulting in a lower surface area and relatively lower interfacial strength when bonded within the MMC.

[0087] The strength of an MMC system can be associated with one or more of three different components: 1) the strength of the copper binder, the strength of the tungsten carbide particles, and the bond strength between the copper binder and the incorporated tungsten carbide particles. Therefore, if the tungsten carbide particles and copper are not well bonded, the MMC may fail under high stress. By giving the carbide particles a larger surface area, the alloy has more area to bond with the carbide particles, thus significantly increasing the interfacial strength.

[0088] Figure 8 The surface morphology of spherical or substantially spherical tungsten particles in an MMC according to an embodiment of the present disclosure is shown. As shown, the microstructure includes “needle-like” morphological features (e.g., texture) of spherical or substantially spherical fused tungsten carbide. The surface is primarily textured with a fine-grained structure, resulting in a high surface area and better interfacial strength when incorporated within the MMC.

[0089] To quantify spherical or substantially spherical fused tungsten carbide particles by their surface features, the fraction of surface area attributable to grain boundaries in a fixed field of view of an optical or SEM image was analyzed. As described herein, the grain boundary area fraction refers to the area attributable to grain boundaries in an image (e.g., an optical or SEM image) of a sample surface (e.g., the surface of a tungsten carbide particle). The grain boundary area fraction can be quantified using images, such as high-contrast or binary images, such as... Figure 9 and Figure 10 Those shown. For example, the number of dark pixels as a fraction of the total number of pixels in the imaging field can correspond to the area fraction of grain boundaries. The inventors have discovered that the conventional "soccer ball-shaped" surface morphology of tungsten carbide particles results in a relatively low area fraction of grain boundaries on the surface of tungsten carbide particles, for example, less than 5%. On the other hand, tungsten carbide particles with a "needle-like" surface morphology have a relatively high area fraction of grain boundaries on the surface of tungsten carbide particles, for example, more than 10% (or about 10%).

[0090] For example, Figure 7The area fraction of grain boundaries in the sample is 3.6%, while Figure 8 The value was 14.2%. Figure 9 yes Figure 7 A binary image. Figure 10 yes Figure 8 The binary image, in which the area fraction obtained by analysis is 14.2%, has a variation of 9.4 when it is divided into nine parts.

[0091] For an object of a given volume, a sphere has the lowest mathematically possible area-to-volume ratio. Therefore, one would expect spherical carbide particles to have a low grain boundary integral number. However, the inventors have discovered that the needle-like surface morphology of tungsten carbide particles produces an unexpectedly high surface area, which in turn results in a high grain boundary integral number. Thus, it is possible to provide tungsten carbide particles that are both spherical and exhibit a high grain boundary area. The high grain boundary integral number can be proportional to the amount of high-strength interface formed between the tungsten carbide particles and the metal matrix, and further proportional to the mechanical and tribological properties of the MMC, including TRS and corrosion resistance.

[0092] Additionally, according to some embodiments, the needle-like morphology includes needle-like structures extending along the surface of the tungsten carbide particles. The needle-like structure has at least one length portion whose length exceeds, for example, 0.5 μm, 1 μm, 2 μm, 3 μm, 4 μm, 5 μm, or a value within the range defined by any two of these values, while its width is less than 2 μm, 1 μm, 0.5 μm, 0.2 μm, 0.1 μm, or a value within the range defined by any two of these values. The aspect ratio of the longest length to the minimum width of the needle-like structure may exceed 2, 5, 10, 20, or a value within the range defined by any two of these values.

[0093] In some embodiments, the interfacial integral of the spherical or substantially spherical fused tungsten carbide particles is 5.0% (or about 5.0%) or greater. In some embodiments, the interfacial integral of the spherical or substantially spherical fused tungsten carbide particles is 10.0% (or about 10.0%) or greater. In some embodiments, the interfacial integral of the spherical or substantially spherical fused tungsten carbide particles is 12.0% (or about 12.0%) or greater. In some embodiments, the interfacial integral of the spherical or substantially spherical fused tungsten carbide particles is 12.0% (or about 12.0%) or greater. In some embodiments, the interfacial integral of the spherical or substantially spherical fused tungsten carbide particles is 20.0% (or about 20.0%) or greater. The interfacial integral may also have values ​​within a range defined by any two of these values.

[0094] Furthermore, the area fraction of grain boundaries in the carbide powder (preferably spherical powder) is preferably greater than or equal to 5%, 10%, 14%, 15%, 20%, or 25%. While there is no preferred upper limit to the grain boundary area fraction, it is generally less than or equal to 50%, 40%, or 30%. Ranges formed by any two of these values ​​(including and excluding endpoints) are also considered, such as 5% to 50%, 10% to 40%, 5% to 40%, 5% to 30%, 10% to 50%, 10% to 40%, 10% to 30%, 10% to 25%, 10% to 20%, 14% to 60%, and 14% to 30%.

[0095] Transition of tungsten carbide : In some embodiments of the invention, the component comprises a carbide that has been heat-treated prior to or during the permeation process. The heat treatment process enhances the performance of the component, most notably its abrasion resistance and / or toughness.

[0096] The application of this heat treatment has yielded surprising results. For example, the hardness of the components is relatively unaffected, perhaps only slightly reduced (compared to components prepared without heat treatment), but wear resistance is significantly increased. It has been found that heat treatment transforms the W2C+WC structure (one of the two forms of tungsten carbide) into a W+WC structure, the significant difference being the presence of metallic W and WC. Unbound by theory, these surprising results are believed to be attributable to the transformation from the W2C+WC structure to the W+WC structure. It is believed that heat treatment of tungsten carbide powder alters the internal structure of the particles, thereby increasing thermal conductivity and / or thermal shock resistance. Standard metal infiltration processes are carried out under temperature and time conditions insufficient to impart the benefits of heat treatment. Studies have found that increasing the temperature and time to promote diffusion with cast tungsten carbide when the metal binder is in the liquid phase, and exceeding conventional infiltration parameters, can achieve similar benefits in wear resistance and toughness.

[0097] In any case, the observation of these unexpected results in components made by the infiltration process from heat-treated carbide powders indicates that heat-treated carbide powders, as disclosed herein, are unexpectedly different in structure and properties from those that have not undergone heat treatment.

[0098] The heat treatment can be carried out in a non-oxidizing atmosphere, exposing the powder to a temperature of at least 1000°C and at most 1250°C, preferably at least 1100°C or 1190°C and at most 1250°C, for 0.5 hours to 50 hours until a partial or complete transformation of the W2C (semi-carbide) phase is achieved.

[0099] The heat treatment is preferably carried out under a vacuum (e.g., in a vacuum furnace) or in a non-reactive or reducing atmosphere, preferably in an oxygen-free atmosphere (such as an argon atmosphere, preferably a low-pressure argon atmosphere).

[0100] The manufacturing method also includes a one-step process in which heat treatment and metal infiltration are performed simultaneously. In this case, the metal infiltration process is modified, for example, by increasing the temperature and / or extending the infiltration time, to achieve heat treatment of the tungsten carbide powder. For example, the metal infiltration process can be carried out under heat treatment conditions.

[0101] The infiltration process can use heat-treated carbides as the sole carbides. Blends of heat-treated and non-heat-treated carbides are also considered. Therefore, the invention includes combinations in which heat-treated and non-heat-treated carbides are blended together to form porous blocks for the infiltration process. The amount of heat-treated carbides in the carbide powder can be 100 wt%, 90 wt%, 80 wt%, 70 wt%, 60 wt%, 50 wt%, 40 wt%, 30 wt%, 20 wt%, or 10 wt% based on the total weight of the carbide powder (i.e., the weight of hard particles such as tungsten carbide (e.g., W and all W carbides)). Ranges formed by any two of these values ​​(including or excluding the endpoints) are also considered. For example, when using blends of heat-treated and non-heat-treated carbides, the amount of heat-treated carbides can range from 10 wt% to 90 wt%, 10 wt% to 50 wt%, 10 wt% to 30 wt%, or 70 wt% to 90 wt%.

[0102] Components made from carbide powder containing heat-treated carbides or composed of heat-treated carbides are particularly suitable for high-stress applications, such as bearings including thrust bearings and radial bearings.

[0103] Binder alloy : In some embodiments of the invention, the component comprises a high-copper-content binder alloy.

[0104] In one embodiment of the invention, the binder alloy for forming the MMC matrix comprises a relatively high copper (Cu) concentration exceeding 55 wt%, 60 wt%, 65 wt%, 70 wt%, 75 wt%, 80 wt%, 85 wt%, or any of these values ​​within a range defined by these values. The high Cu content provides improved thermal conductivity, among other advantages. Binder alloys such as those disclosed in WO 2022 / 212588 (the entire contents of which are incorporated herein by reference) can also be used.

[0105] While elemental copper can provide one of the highest thermal conductivities, it may not provide one or more other desired properties related to the manufacture of MMC or its resulting mechanical properties. To improve various mechanical properties of the matrix, including the strength, hardness, and abrasion resistance of the MMC matrix, which in turn improves the corresponding mechanical properties of the resulting MMC, and improves the aforementioned permeation properties used to form the liquid matrix, the inventors have discovered a combination of alloying elements used to alloy with Cu to form a raw material alloy for forming the matrix. According to various embodiments, in addition to the relatively high Cu content mentioned above, the elemental composition of the raw material alloy used to form the matrix includes: tin (Sn) at a concentration of more than 1.4 wt%, nickel (Ni) at a concentration of more than 3.5 wt%, and manganese (Mn) at a concentration of more than 5.6 wt%. According to embodiments, to maintain the aforementioned high Cu content, the combined concentration of Sn, Ni, and Mn does not exceed 20 wt%, 30 wt%, 40 wt%, 45 wt%, or has a value within a range defined by any of these values.

[0106] In some embodiments, the elemental composition of the raw material alloy used to form the MMC matrix includes Sn at concentrations exceeding 1.4 wt%, 1.6 wt%, 1.7 wt%, 1.8 wt%, 1.9 wt%, 2.0 wt%, 2.1 wt%, 2.2 wt%, 2.3 wt%, 2.4 wt%, 2.6 wt%, or within the range defined by any of these values. For example, the elemental composition includes Sn at concentrations of 1.4 wt% to 2.6 wt%, 1.7 wt% to 2.3 wt%, or about 2.0 wt%. The elemental composition of the raw material alloy also includes Mn at concentrations exceeding 5.6 wt%, 6.4 wt%, 6.8 wt%, 7.2 wt%, 7.6 wt%, 8.0 wt%, 8.4 wt%, 8.8 wt%, 9.2 wt%, 9.6 wt%, 10.4 wt%, or within the range defined by any of these values. For example, the elemental composition includes 5.6 wt% to 10.4 wt%, 6.8 wt% to 9.2 wt%, or about 8.0 wt% of Mn. The elemental composition of the raw material alloy further includes Ni at concentrations exceeding 3.5 wt%, 4.0 wt%, 4.3 wt%, 4.5 wt%, 4.7 wt%, 5.0 wt%, 5.3 wt%, 5.5 wt%, 5.8 wt%, 6.0 wt%, 6.5 wt%, or concentrations within the range defined by any of these values. For example, the elemental composition includes 3.5 wt% to 6.5 wt%, 4.3 wt% to 5.8 wt%, or about 5.0 wt% of Ni.

[0107] In some embodiments, the elemental composition of the raw material alloy may include additional elements, which may include incidental impurities with a combined concentration of less than 10 wt%, 5 wt%, 2 wt%, 1 wt%, or values ​​within the range defined by any of these values. In some embodiments, Cu may be present as a balance in the elemental composition, in addition to the additional elements or impurity elements.

[0108] Advantageously, a relatively high Cu concentration in the feedstock can provide high thermal conductivity and / or electrical conductivity. It should be understood that high thermal conductivity can be indirectly measured by measuring electrical conductivity. According to the embodiment, the electrical conductivity of the feedstock is greater than 2.0 MSiemens (MS) / m, 2.5 MS / m, 3.0 MS / m, 3.5 MS / m, or a value within a range defined by any of these values. Without being bound by any theory, the feedstock may have thermal conductivity that is related to electrical conductivity by, for example, the Wiedemann-Franz law. According to the embodiment, the thermal conductivity of the feedstock may be 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 within a range defined by any of these values.

[0109] The combination of components provides high strength and high thermal conductivity, which in turn provides high thermal shock resistance. In some embodiments, the thermal shock resistance is 600 W / m or higher, in preferred embodiments it is 650 W / m or higher, and in more preferred embodiments it is 700 W / m or higher.

[0110] 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, which is the source of the matrix for MMC. These advantages may include one or more of the following: lower melting temperature, lower contact angle with tungsten carbide, and / or lower reactivity with tungsten carbide. The combination of elements can further provide advantages over relatively pure elemental Cu, which is the source of the matrix for MMC, including one or more of the following: higher strength, higher wear resistance, and / or higher hardness.

[0111] In some embodiments, 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 are present at a combination concentration of less than 10 wt%, 5 wt%, 2 wt%, 1 wt%, or within a range defined by any of these values, the combination of elements in the feedstock alloy can provide further advantages over elemental Cu.

[0112] In another preferred embodiment of the invention, the Co content of the adhesive is limited or preferably zero. In some embodiments, the Co content of the adhesive is less than 1% by weight. In some embodiments, the Co content of the adhesive is less than 0.1% by weight. In some embodiments, the Co content of the adhesive is less than 0.01% by weight.

[0113] Preparing raw materials in alloy form can help lower the melting temperature of the raw material alloy, allowing MMC to be formed efficiently at lower temperatures. The lower melting temperature of the alloy form of the raw material may be advantageous for several reasons. One reason is compatibility with existing methods for manufacturing MMC, including those mentioned above. Due to temperature limitations in some existing manufacturing methods, raw materials with melting temperatures exceeding 1300 K used to form the MMC matrix may be difficult to fully melt to penetrate the reinforcing particles used in the manufacturing process into the MMC matrix. Therefore, based on the melting temperatures of Cu, Mn, and Ni (1083°C (1356 K), 1244°C (1517 K), and 1453°C (1726 K), respectively), the inventors have found that it is advantageous to present raw materials containing these elements in alloy form with melting temperatures lower than those of each element. The inventors have found that it is advantageous to provide raw material alloys with lower melting temperatures when combinations of Cu, Sn, Mn, and Ni included in the aforementioned elemental composition are present in alloy form, thereby improving manufacturability. Therefore, according to the embodiments, the raw material in alloy form has a composition such that the solidus temperature of the alloy is lower than the melting temperature of substantially pure Cu. In some embodiments, the solidus temperature of the alloy is lower than 1300K, 1275K, 1250K, 1225K, 1200K, or a solidus temperature within a range defined by any of these values.

[0114] Applications : The compositions and methods described herein can be used to manufacture a variety of components. These components can be monolithic pieces entirely manufactured from infiltration-cast MMC, or they can be substrate materials bonded to MMC. Infiltration processes are commonly used for drill bodies, and the compositions and methods of this invention can be used to manufacture drill bodies. However, the unique performance profiles of these compositions and methods allow infiltration components to be used in a wider range of applications.

[0115] Such applications include components, such as small parts, including but not limited to turning tips, micro drills, bucket cutters, and other cutting tools, blades, can molds, wire drawing dies, cutting edges, water jet nozzles, and wear-resistant parts in general.

[0116] Such applications also include components, such as medium-sized components, including but not limited to fracturing valves, subsea valve assemblies, mining inserts, pump bodies, and thrust bearings.

[0117] Such applications also include components, such as large components, including but not limited to bearings, pads for rotary guide tools, flow control valves and other valves, throttle valves, nozzles and bushings.

[0118] Applications in open-pit mining include the following components: wear-resistant sleeves and / or wear-resistant hardened surfaces for slurry piping, inserts, valves, airlock valves, seats, mud pump assemblies (including pump housings or impellers or mud pump assemblies), ore feed chute assemblies (including trough blocks), separating screens (including but not limited to rotary crushers, banana screens, and vibrating screens), liners for autogenous and semi-autogenous mills, ground engagement tools and teeth, guards and adapters, wear plates and rock boxes (including liners for buckets and dump trucks), heel blocks on mining shovels, grader blades and hardened surfaces for grader blades, stacker reclaimers, screening crushers, jaw crushers, ripper teeth, cutting edges, and general wear-resistant packaging for mining components and other crushing components.

[0119] Downstream oil and gas applications include the following components: downhole casing and casing, drill pipe and mud motors, fracturing pump sleeves, fracturing impellers, fracturing stirrer pumps, limit rings, drill bits and drill bit assemblies, directional drilling equipment (including slips, pads, stabilizers and centralizers) and coatings for directional drilling equipment, blowout preventers and coatings for blowout preventers and blowout preventer assemblies (including shear gates), oilfield pipes and coatings for oilfield pipes, sucker rods and connectors, lift plungers, Neyrfor rotors, manual lift casings, and ESP pump housings and impellers, flow lines and subsea flow lines.

[0120] Applications in the upstream oil and gas sector include: process vessels and coatings for process vessels (including steam generating equipment), amine containers, distillation towers, cyclone separators, catalytic crackers, general refinery pipelines, insulation and corrosion protection, sulfur recovery units, convection hoods, acid stripping tower pipelines, scrubbers, hydrocarbon storage tanks, and other refinery equipment and containers.

[0121] Applications in the pulp and paper industry include the following components: rolls for paper machines, including Yankee dryers, through-hole dryers and other dryers, calender rolls, machine rolls, pressure rolls, winding rolls, digesters, pulp mixers, pulpers, pumps, boilers, shredders, tissue paper machines, roll and bundle handling machines, fiber guiding systems (such as deflector blades, doctor blades), evaporators, pulp mills, headboxes, wire components, pressing components, MG cylinders, pope reels, winding machines, vacuum pumps, deflators and other pulp and paper equipment.

[0122] Applications in the power generation field include the following components: boiler tubes, dust collectors, fireboxes, turbines, generators, cooling towers, condensers, chutes and channels, screw conveyors, bag filters, pipes, ID fans, coal pipelines, and other power generation components.

[0123] Applications in the agricultural sector include the following components: chutes, root cutting blades, sugarcane harvesting knives, hammers, troughs, main fan blades, secondary fan blades, screw conveyors, components commonly found in mining applications, and other agricultural applications.

[0124] Construction and building applications include: cement chutes, cement pipes, bag filters, mixing equipment, structural components (such as I-beams and concrete substitutes), flooring, kitchen counters, and other applications.

[0125] Applications in the field of machine components include the following components: journals, hydraulic cylinders, paper rollers, gearboxes, drive rollers, impellers, engine deck reconstruction, drive shafts and other shafts, general repair and dimensional restoration applications, and other machine component applications.

[0126] Applications in the steel sector include the following components: cold rolling mills, hot rolling mills, wire rod mills, galvanizing lines, continuous pickling lines, continuous casting rolls and other ironmaking rolls, as well as other steel applications.

[0127] Other applications include vehicle components such as engines, motors, automatic or manual transmissions, differentials, axles, brakes, and body parts; medical devices such as implantable devices, device housings, surgical equipment, and surgical instruments; and aerospace applications such as turbines, fans, shafts, nozzles, propellers, fins, and other components, including fins, wings, tail fins, and fuselage parts, for propellers, jet aircraft, or rocket equipment.

[0128] Other applications include cold forming tools, drill bits for space mineral exploration, wire drawing dies, inserts for sugar crushers, and crushers for oil sands applications.

[0129] Examples Example 1 (comparative) : MMC articles were prepared by liquid metal infiltration as follows. A portion of 230×450 mesh cast tungsten carbide (CTC) containing spherical particles (aspect ratio: 1:1) was placed in a mold, and a portion of Cu53, nominally composed of 53 wt% Cu, 25 wt% Mn, 15 wt% Ni, and 7 wt% Zn, was placed on top. The system was heated at 1180 °C for 0.25 h and then cooled before testing to produce article 1.

[0130] Product 1 exhibits a volume loss of 675 mm³ for B611. 3(0.675cc), Rockwell hardness 49. CTC powder exhibits Vickers hardness (HV) of 2800 to 2960.

[0131] like Figure 11 a to Figure 11 As shown in d, when Palmqvist test was performed using a Vickers indenter (300 gf), the CTC in product 1 exhibited standard cracks and fracture.

[0132] Example 2 : The CTC powder as in Example 1 was placed in a vacuum furnace and kept at 1225°C for 20 hours and then cooled. Example 1 was then repeated, but using heat-treated CTC powder, to produce Article 2.

[0133] Product 2 exhibits a volume loss of 557 mm³ for B611. 3 (0.557cc), Rockwell hardness 49. CTC powder exhibits a Vickers hardness (HV) of approximately 2125.

[0134] like Figure 11 e to Figure 11 As shown in h, when subjected to a Vickers indenter (300 gf), the CTC in product 2 exhibited little to no breakage (Palmqvist test).

[0135] Examples 3 to 7 : MMC articles in the form of 10 mm square bars were prepared using the tungsten carbide shown in Table 1 and the binder alloy shown in Table 2 via liquid metal infiltration as in Example 1. WC-D is a spherical cast tungsten carbide with a textured surface. Examples 3 to 5 are comparative examples. The Charpy impact toughness of the 10 mm square bars was tested according to ASTM E23, without a V-notch.

[0136] like Figure 11 As shown, the absence or reduction of cracks after Vickers indentation indicates that the toughness of CTC powder was unexpectedly enhanced after the heat treatment process. From the above examples, it can be seen that the use of heat-treated tungsten carbide powder surprisingly improves the overall toughness of the composite material.

[0137] Example 8 : Coarse-grained spherical cast tungsten carbide with a grain size of 301 μm was heat-treated in a vacuum furnace at 1225 °C for 20 hours. The particles were placed in a mold, and a portion of an alloy with a nominal composition of 85 wt% Cu, 8 wt% Mn, 5 wt% Ni, and 2 wt% Sn was placed on top. Penetration was performed at 1180 °C for 30 minutes. The constituent parts were subjected to a high-stress wear test according to ASTM B611. Cemented tungsten carbide with 10 wt% cobalt and a medium grain size ranging from 1.4 μm to 3.4 μm was also tested for comparison.

[0138] like Figure 12 As shown, 1cm was achieved over a sliding distance of 4902m. 3 The material removal is similar to that observed in the comparative cemented tungsten carbide. All test protocols (such as ASTM test procedures) discussed or indirectly mentioned herein are available and known to those skilled in the art.

[0139] Although several components, techniques and aspects have been described with a degree of specificity, it is clear that many changes can be made to the particular designs, constructions and methods described above without departing from the spirit and scope of this disclosure.

[0140] Some features described in this disclosure in the context of a single implementation may also be implemented in combination in a single implementation. Conversely, various features described in the context of a single implementation may also be implemented individually or in any suitable sub-combination in multiple implementations. Furthermore, although the foregoing features may be described as functioning in certain combinations, in some cases, one or more features from the claimed combination may be removed from the combination, and the combination may be defined by the claims as any sub-combination or a variation of any sub-combination.

[0141] Furthermore, while methods may be depicted in the accompanying drawings or described in the specification in a specific order, such methods do not need to be executed in the specific order shown or in a sequential order, and it is not necessary to execute all methods to achieve the desired result. Other methods not depicted or described may be incorporated into the example methods and procedures. For example, one or more additional methods may be executed before, after, simultaneously with, or between any described methods. Furthermore, in other implementations, these methods may be rearranged or reordered. Moreover, the separation of various system components in the above embodiments should not be construed as requiring such separation in all embodiments, 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 also within the scope of this disclosure.

[0142] Unless otherwise specifically stated, or otherwise understood in the context in which they are used, conditional language such as “can,” “able,” “may,” or “may” is generally intended to convey whether certain embodiments include or exclude certain features, elements, and / or steps. Therefore, such conditional language is generally not intended to imply that one or more embodiments require features, elements, and / or steps in any way.

[0143] Unless otherwise explicitly stated, connective language such as the phrase "at least one of X, Y, and Z" should generally be understood to mean that, in the context, an item, term, etc., can be any of X, Y, or Z. Therefore, such connective language generally does not imply that some implementation must contain at least one of X, at least one of Y, and at least one of Z.

[0144] The degree language used herein, such as the terms “approximately,” “about,” “usually,” and “substantially”, means values, quantities, or characteristics that are close to the stated value, quantity, or characteristic, yet still perform the desired function or achieve the desired result. For example, the terms “approximately,” “about,” “substantially,” and “substantially” can refer to quantities within 10% or less, 5% or less, 1% or less, 0.1% or less, and 0.01% or less of the stated quantity. If the stated quantity is 0 (e.g., none, not present), the above ranges can be specific ranges and not within a specific percentage of that value. For example, quantities within 10% or less by weight / volume, 5% or less by weight / volume, 1% or less by weight / volume, 0.1% or less by weight / volume, and 0.01% or less by weight / volume.

[0145] Several embodiments have been described in conjunction with the accompanying drawings. The drawings are drawn to scale, but this scale should not be limiting, as dimensions and scales other than those shown are contemplated and within the scope of the disclosed invention. Distances, angles, etc., are illustrative only and do not necessarily have an exact relationship to the actual dimensions and layout of the illustrated apparatus. Components may be added, removed, and / or rearranged. Furthermore, any particular feature, aspect, method, performance, characteristic, quality, attribute, element, etc., disclosed herein in connection with various embodiments can be used in all other embodiments set forth herein. Additionally, it should be understood that any method described herein can be practiced using any apparatus suitable for performing the steps.

[0146] Although several embodiments and variations thereof have been described in detail, other modifications and methods of using them will be apparent to those skilled in the art. Therefore, it should be understood that various applications, modifications, material substitutions and equivalent substitutions may be made to the equivalents without departing from the unique and inventive disclosure or the scope of the claims herein.

Claims

1. A tungsten carbide powder, said tungsten carbide powder comprising particulates having a crystal interface integral of 20% to 50% and an average aspect ratio of less than 1.

3.

2. A heat-treated tungsten carbide powder, said tungsten carbide powder being prepared by heating the tungsten carbide powder of claim 1 to a temperature of 1000°C to 1250°C for a period of 0.5 hours to 50 hours under a vacuum, a non-reactive atmosphere, or a reducing atmosphere.

3. The heat-treated tungsten carbide powder according to claim 2, wherein the heat-treated tungsten carbide contains a tungsten carbide (monocarbide) phase, a metallic tungsten phase, and optionally a half-carbide (W2C) phase, wherein the tungsten phase accounts for 1% to 50% by weight of the heat-treated tungsten carbide powder.

4. The heat-treated tungsten carbide according to claim 1, wherein the carbon content of the heat-treated tungsten carbide is from 3.0% to 4.5% by weight.

5. A composition comprising the tungsten carbide powder of claim 1 and an alloy comprising 50% to 85% copper to form a metal matrix composite material.

6. The composition according to claim 5, wherein the alloy further comprises 1.4 wt% to 2.6 wt% Sn, 5.6 wt% to 10.4 wt% Mn and 3.5 wt% to 6.5 wt% Ni.

7. A method for manufacturing a metal matrix composite article, the method comprising: Obtain tungsten carbide powder containing heat-treated tungsten carbide powder; The tungsten carbide powder is heated to a certain temperature and maintained for a sufficient time in the presence of a binder alloy, so that the binder alloy melts and permeates the tungsten carbide powder to form a permeated product; as well as The metal matrix composite article is obtained by cooling the infiltrated article to cure the adhesive alloy; and The adhesive alloy contains 50% to 85% copper by weight.

8. The method of claim 7, wherein the heat-treated tungsten carbide powder comprises particulates having a crystal interface fraction of 20% to 50% and an average aspect ratio of less than 1.

3.

9. The method of claim 7, wherein the carbon content of the heat-treated tungsten carbide powder is from 3.0% to 4.5% by weight.

10. The method of claim 7, wherein the heat-treated tungsten carbide powder contains 1% to 50% by weight of tungsten phase and may or may not contain a half-carbide (W2C) phase.

11. A metal matrix composite material article, which is prepared by the method of claim 7.

12. A metal matrix composite article, wherein the metal matrix composite article comprises tungsten carbide particles in an alloy matrix, The tungsten carbide particles have a grain interface integral of 20% to 50% and an aspect ratio of 1 to 1.3, and the tungsten carbide particles comprise 10% to 100% by weight of heat-treated tungsten carbide particles based on the total weight of the tungsten carbide particles. The alloy matrix contains 50% to 85% copper by weight.

13. The metal matrix composite article of claim 12, wherein the metal matrix composite article exhibits a thickness of 6 mm when measured according to ASTM G65. 3 Or even lower abrasion resistance.

14. The metal matrix composite article of claim 12, wherein the metal matrix composite article exhibits a volume loss of 0.8 cc or less when measured according to ASTM B611.

15. The metal matrix composite article according to claim 12, wherein the metal matrix composite article exhibits a Charpy impact toughness of at least 6.8 J.

16. The metal matrix composite article according to claim 12, wherein the tungsten carbide particles have a D50 of 1 μm to 10 μm and a TRS greater than or equal to 360 ksi.

17. The metal matrix composite article according to claim 12, wherein the tungsten carbide particles have a D50 of 11 μm to 20 μm and a TRS greater than or equal to 280 ksi.

18. The metal matrix composite article according to claim 12, wherein the tungsten carbide particles have a D50 of 21 μm to 40 μm and a TRS greater than or equal to 230 ksi.

19. The metal matrix composite article according to claim 12, wherein the tungsten carbide particles have a D50 of 41 μm to 60 μm and a TRS greater than or equal to 180 ksi.

20. The metal matrix composite article according to claim 12, wherein the tungsten carbide particles have a D50 of 61 μm to 80 μm and a TRS greater than or equal to 160 ksi.

21. The metal matrix composite article according to claim 12, wherein the tungsten carbide particles have a D50 of 81 μm to 100 μm and a TRS greater than or equal to 140 ksi.

22. The metal matrix composite article according to claim 12, wherein the tungsten carbide particles have a D50 of 111 μm to 200 μm and a TRS greater than or equal to 100 ksi.

23. The metal matrix composite article according to claim 12, wherein the tungsten carbide particles have a D50 of 201 μm to 500 μm and a TRS greater than or equal to 80 ksi.

24. The metal matrix composite article according to claim 12, wherein the tungsten carbide particles have a D50 of 501 μm to 1000 μm and a TRS greater than or equal to 60 ksi.

25. The metal matrix composite article according to claim 12, wherein the tungsten carbide particles have a D50 of 1001 μm to 2000 μm and a TRS greater than or equal to 50 ksi.

26. The metal matrix composite article of claim 12, wherein the tungsten carbide particles comprise 10% to 100% by weight of heat-treated tungsten carbide particles based on the total weight of the tungsten carbide particles.

27. The heat-treated tungsten carbide particles according to claim 26, wherein the heat-treated tungsten carbide particles have been heated to a temperature of 1000°C to 1250°C for 0.5 hours to 50 hours in a vacuum or non-reactive atmosphere prior to the liquid metal infiltration process.

28. The heat-treated tungsten carbide particles according to claim 26, wherein the heat-treated tungsten carbide particles are heated in the presence of liquid metal during the liquid metal infiltration process for a period of 0.5 hours to 50 hours at a temperature of 1000°C to 1250°C, and preferably 1190°C to 1250°C.

29. The heat-treated tungsten carbide particles according to claim 26, wherein the carbon content of the heat-treated tungsten carbide particles is from 3.0% to 4.5% by weight.

30. The heat-treated tungsten carbide particles according to claim 26, wherein the heat-treated tungsten carbide particles contain 1% to 50% by weight of tungsten phase and optionally contain a half-carbide (W2C) phase.

31. The metal matrix composite article according to claim 12, wherein the alloy matrix further comprises 1.4 wt% to 2.6 wt% Sn, 5.6 wt% to 10.4 wt% Mn and 3.5 wt% to 6.5 wt% Ni.

32. The metal matrix composite article according to claim 12, wherein the composite material includes a first region in which the metal matrix composite material is a high-strength matrix metal composite material, and a second region in which the metal matrix composite material is a high-wear-resistant matrix metal composite material.

33. The metal matrix composite article of claim 12, wherein the matrix metal composite article comprises a plurality of regions, each region comprising 10% to 100% by weight of the heat-treated tungsten carbide particles based on the total weight of the tungsten carbide particles in the respective region.

34. The method according to claim 7, wherein: The process involves heating tungsten carbide powder to a temperature of 1000°C to 1250°C for 0.5 hours to 50 hours under vacuum, a non-reactive atmosphere, or a reducing atmosphere, wherein the tungsten carbide powder comprises particulates with a grain interface integral of 20% to 50% and an average aspect ratio of less than 1.3, thereby producing tungsten carbide powder comprising at least 10% by weight of heat-treated tungsten carbide powder based on the total weight of the tungsten carbide powder; or The obtaining process includes heating the tungsten carbide powder having a grain interface integral of 20% to 50% and an average aspect ratio of less than 1.3 at a temperature of 1000°C to 1250°C in the presence of the molten binder alloy for a period of 0.5 hours to 50 hours, wherein 100% by weight of the tungsten carbide powder in the infiltrated article is the heat-treated tungsten carbide powder.

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