Cemented carbide powders for additive manufacturing and sintered bodies made therefrom

Abstract

Sintered cemented carbide powder compositions for the production of various articles by additive manufacturing are described. The individual particles of the powder composition comprise metal carbide particles sintered together with a metal binder. The sintered cemented carbide particles comprise a unimodal particle size distribution wherein the sintered cemented carbide particles have a D50 greater than 12 [mu] m and the sintered cemented carbide particles have a D10 greater than 5 [mu] m. The metal binder may be present in an amount of from 9% to 11% by weight based on the total weight of the sintered cemented carbide particles. A sintered cemented carbide body comprising the sintered cemented carbide powder composition is also described. Methods of making the sintered cemented carbide powder compositions and methods of making the sintered cemented carbide bodies are also described.

Description

Technical Field

[0001] The present invention relates to a sintered cemented carbide powder composition for additive manufacturing and a sintered cemented carbide body additively manufactured using the sintered cemented carbide powder composition. Background Art

[0002] Additive manufacturing offers an efficient and cost-effective alternative to traditional molding-based product manufacturing techniques. With additive manufacturing, the significant time and expense of mold and / or die construction and other processing can be avoided. Furthermore, additive manufacturing technology allows for efficient material utilization by allowing for recycling within the process. Most importantly, additive manufacturing offers significant freedom in product design. Products with highly complex shapes can be produced without significant expense, allowing a range of product designs to be developed and evaluated before a final design is selected. Summary of the Invention

[0003] A sintered cemented carbide powder composition for producing various articles by additive manufacturing is provided. The individual particles of the powder composition comprise metal carbide particles sintered together with a metal binder. The sintered cemented carbide particles comprise a unimodal particle size distribution, wherein the D50 of the sintered cemented carbide particles is greater than 12 μm and the D10 of the sintered cemented carbide particles is greater than 5 μm. The metal binder can be present in an amount of 9 wt% to 11 wt% based on the total weight of the sintered cemented carbide particles. Methods for making the sintered cemented carbide powder composition and methods for making the sintered cemented carbide bodies are also provided.

[0004] Disclosed herein is a powder composition for binder jet printing, the powder composition comprising sintered cemented carbide particles, the sintered cemented carbide particles having a D50 greater than 12 μm, and the sintered cemented carbide particles having a D10 greater than 5 μm, the sintered cemented carbide particles comprising 9 wt % to 11 wt % of a metal binder based on the total weight of the sintered cemented carbide particles, wherein the powder composition has an apparent density of 3.0 g / cm 3 Up to 6.0 g / cm 3 .

[0005] Also disclosed herein is a method for preparing a powder composition for binder jet printing, the method comprising grinding tungsten carbide particles, a metal binder, a polymer binder, and a solvent to form a slurry; spray drying the slurry to form a powder; sintering the powder; grinding and sieving the powder; and sintering the powder in a partially liquid state to form the powder composition, wherein the powder composition comprises carbide particles having a D50 greater than 12 μm, a D10 greater than 5 μm, and an apparent density of 3.0 g / cm 3 Up to 6.0 g / cm 3 , and the cemented carbide particles contain 9 wt % to 11 wt % of a metal binder based on the total weight of the cemented carbide particles.

[0006] Also disclosed herein is a binder jet printed sintered cemented carbide body comprising sintered cemented carbide particles having a D50 greater than 12 μm and a D10 greater than 5 μm, the sintered cemented carbide particles comprising 9 wt% to 11 wt% of a metallic binder based on the total weight of the sintered cemented carbide particles, wherein the sintered cemented carbide body has a theoretical density percentage of at least 99%. The binder jet printed sintered cemented carbide body is formed by binder jet printing the sintered cemented carbide particles to form a green body, and then sintering the green body.

[0007] Also disclosed is a method for forming a sintered cemented carbide body, the method comprising: binder jetting a powder composition comprising sintered cemented carbide particles, the sintered cemented carbide particles having a D50 greater than 12 μm, and the sintered cemented carbide particles having a D10 greater than 5 μm, the sintered cemented carbide particles comprising 9 wt% to 11 wt% of a metal binder based on the total weight of the sintered cemented carbide particles, and the sintered cemented carbide particles having an apparent density of 3.0 g / cm 3 Up to 6.0 g / cm 3 , and the sintered cemented carbide particles have a printing binder to form a green body; and sintering the green body to provide the sintered cemented carbide body. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 is a scanning electron microscope (SEM) image of the cross section of C1.

[0009] Figure 2 is the SEM of the cross section of C2. DETAILED DESCRIPTION

[0010] The present invention disclosed herein is directed to a powder composition for additive manufacturing, comprising sintered cemented carbide particles having a D50 greater than 12 μm and a D10 greater than 5 μm, the sintered cemented carbide particles comprising 9 wt% to 11 wt% of a metal binder based on the total weight of the sintered cemented carbide particles, wherein the powder composition has an apparent density of 3.0 g / cm 3 Up to 6.0 g / cm 3 .

[0011] The powder composition can be used in any suitable additive manufacturing technology to form three-dimensional parts. The term "additive manufacturing technology" refers to a process for forming a three-dimensional object by continuously adding material to the object layer by layer. The layered construction on a layer by layer basis enables easy formation of undercuts and complex geometries that could not be formed using previous conventional manufacturing methods or required considerable effort and expense. The three-dimensional object can be based on a 3D model of the component object, which can be electronically designed as an electronic file with design parameters. Additive manufacturing may also be referred to as 3D printing. The additive manufacturing technology of the present invention comprises a process for forming a ceramic powder into a sintered cemented carbide body.

[0012] Additive manufacturing processes can include, for example, binder jetting. As used herein, "binder jetting" or "binder jet" refers to a method of producing a component by selectively spraying droplets of a liquid binder onto a bed of powder (e.g., ceramic powder) based on a 3D model of the component, causing the particles to adhere to the cross-section, depositing additional powder, and then depositing the binder to form the next layer of the object, and repeating this process until the green component is complete. For example, a binder jetting device spreads a layer of metal, ceramic, or cermet powder in a build box, moves a print head over the powder layer, depositing a liquid binder according to the design parameters of the layer, dries the layer, lowers the build box, spreads a new layer of ceramic powder, and repeats the process until the green article (body) is complete. Although binder jetting is primarily described herein as an additive manufacturing process for making the materials of the present invention, other types of additive processes may be suitable for use herein.

[0013] The sintered cemented carbide particles of the powder composition comprise individual metal carbide grains sintered and bonded together by a metal binder. The sintered cemented carbide particles may have a substantially spherical shape. As used herein, "spherical" means that the particles are generally spherical, with substantially no flat or concave surface areas on their convex curved outer surface, and have an aspect ratio of 1:1.

[0014] The D50 of the sintered cemented carbide particles of the powder composition may be greater than 12 μm, such as at least 13 μm, such as at least 14 μm. The D50 of the sintered cemented carbide particles of the powder composition may be not greater than 20 μm, such as not greater than 18 μm, such as not greater than 16 μm. The D50 of the sintered cemented carbide particles of the powder composition may be greater than 12 μm to 20 μm, such as 13 μm to 18 μm, such as 14 μm to 16 μm. As used herein, "D50" means the point of the particle size distribution at which 50% or more of the total volume of the material in the sample is contained. For example, a D50 of 12 μm means that 50% of the particles in the sample are less than 12 μm in size.

[0015] The D10 of the sintered cemented carbide particles of the powder composition may be at least 5 μm, such as at least 6 μm, such as at least 7 μm. The D10 of the sintered cemented carbide particles of the powder composition may be no greater than 10 μm, such as no greater than 9 μm. The D10 of the sintered cemented carbide particles of the powder composition may be from 5 μm to 10 μm, such as from 6 μm to 9 μm, such as from 7 μm to 9 μm. As used herein, "D10" means the point of the particle size distribution at which 10% or more of the total volume of the material in the sample is contained. For example, a D10 of 5 μm means that 10% of the particles in the sample are 5 μm or less in size.

[0016] The D90 of the sintered cemented carbide particles of the powder composition can be at least 10 μm, such as at least 15 μm, such as at least 18 μm. The D90 of the sintered cemented carbide particles of the powder composition can be less than 30 μm, such as not more than 25 μm, such as not more than 22 μm. The D90 of the sintered cemented carbide particles of the powder composition can be from 10 μm to less than 30 μm, such as from 15 μm to 25 μm, such as from 18 μm to 22 μm. As used herein, "D90" means the point of the particle size distribution at which 90% or more of the total volume of the material in the sample is contained. For example, a D90 of 25 μm means that 90% of the particles of the sample are less than 25 μm in size.

[0017] The powder particle size distribution described and claimed herein can be measured using a laser diffraction particle size analyzer (S-3500, commercially available from Microtrac MRB). The sintered cemented carbide particles comprise one or more metal carbides. The metal carbides may comprise Group IVB metal carbides, Group VB metal carbides, Group VIB metal carbides, or combinations thereof. For example, the sintered cemented carbide particles may comprise tungsten carbide, chromium carbide, titanium carbide, vanadium carbide, tantalum carbide, niobium carbide, zirconium carbide, and / or hafnium carbide. The sintered cemented carbide particles may comprise tungsten carbide and a second metal carbide. The tungsten carbide may be present in an amount of at least 80% to 85% by weight based on the total weight of the sintered cemented carbide particles. If present, the second metal carbide may be present in an amount of 0.1% to 5% by weight based on the total weight of the sintered cemented carbide particles.

[0018] The sintered cemented carbide particles may not contain multiple metals and / or non-stoichiometric metal carbides. Bimetallic carbides and / or low-metal carbides include, but are not limited to, η phase (Co3W3C or Co6W6C), W2C, and / or W3C. Additionally, the sintered cemented carbide particles may exhibit a uniform or substantially uniform microstructure.

[0019] As previously mentioned, the sintered cemented carbide particles include a metal binder. The metal binder can include cobalt, a cobalt alloy, nickel, a nickel alloy, iron, an iron alloy, or a combination thereof. The metal binder can further include one or more additives, such as a precious metal additive. Examples of precious metal additives that can be used in the present invention include, but are not limited to, platinum, palladium, rhenium, rhodium, and ruthenium, and alloys thereof. Other additives include molybdenum, silicon, or a combination thereof. If present, the additive can be present in the metal binder in an amount of 0.1% to 10% by weight of the sintered cemented carbide particles based on the gross weight of the sintered cemented carbide particles.

[0020] The metal binder can be present in the sintered cemented carbide particles in an amount of at least 9 wt %, such as 9.1 wt %, such as 9.5 wt %, based on the total weight of the sintered cemented carbide particles. The metal binder can be present in the sintered cemented carbide particles in an amount of not more than 11 wt %, such as not more than 10.9 wt %, such as not more than 10.5 wt %, based on the total weight of the sintered cemented carbide particles. The metal binder can be present in the sintered cemented carbide particles in an amount of 9 to 11 wt %, such as 9.1 to 10.9 wt %, such as 9.5 to 10.5 wt %, based on the total weight of the sintered cemented carbide particles. The metal binder can be present in the sintered cemented carbide particles in an amount of up to 10 wt %, based on the total weight of the sintered cemented carbide particles.

[0021] The average individual particle porosity of the sintered cemented carbide particles can be at least 2% by volume, such as 3% by volume, such as 4% by volume. The average individual particle porosity of the sintered cemented carbide particles can be less than 20% by volume, such as less than 17% by volume, such as less than 15% by volume, such as less than 10% by volume, such as less than 5% by volume. The average individual particle porosity of the sintered cemented carbide particles can be from 2 to 20% by volume, such as from 3 to 17% by volume, such as from 4 to 15% by volume, such as from 4 to 10% by volume, such as from 2 to 10% by volume, such as from 2 to 5% by volume. As used herein, "individual particle porosity" refers to the volume percentage of pores in an individual particle based on the total volume of the particle. That is, if the particle porosity of an individual particle is 20% by volume, 80% by volume of the particle contains material such as metal carbide and / or metal binder.

[0022] The powder composition may have an apparent density of at least 3.0 g / cm 3 , such as at least 3.5 g / cm 3 , such as at least 4.0 g / cm 3 The apparent density of the powder composition may be no greater than 6.0 g / cm 3 , such as not more than 5.5 g / cm 3 , such as not more than 5.1 g / cm 3 The apparent density of the powder composition may be 3.0 g / cm 3 Up to 6.0 g / cm 3 , such as 3.5 g / cm 3 Up to 5.5 g / cm 3 , such as 4.0g / cm 3 Up to 5.1 g / cm 3 As used herein, "apparent density" means the mass per unit volume of a powder or granules in a loose state. Apparent density may also be referred to as bulk density. Apparent density can be determined using a Hall flowmeter funnel according to ASTM B212 Standard Test Method for Apparent Density of Free-Flowing Metal Powders.

[0023] The powder composition may have a tap density of at least 3.0 g / cm 3 , such as at least 4.0 g / cm 3 , such as at least 5.0 g / cm 3 The tap density of the powder composition may be no greater than 8.0 g / cm 3 , such as not more than 7.5 g / cm 3 , such as not more than 7.0 g / cm 3 The tap density of the powder composition may be 3.0 g / cm 3 Up to 8.0 g / cm 3, such as 4.0 g / cm 3 Up to 7.5 g / cm 3 , such as 5.0g / cm 3 Up to 7.0 g / cm 3 As used herein, "tap density" means the mass per unit volume of a powder once the powder has been tapped a defined number of times. Tap density can be determined according to ASTM B527 Standard Test Method for Tap Density of Metal Powders and Compounds.

[0024] The ratio of the tap density to the apparent density (Hausner ratio) of the powder composition may be at least 1.10, such as at least 1.20, such as greater than 1.20, such as greater than 1.25. The Hausner ratio of the powder composition may be no greater than 1.30, such as no greater than 1.29, such as no greater than 1.28, such as no greater than 1.27. The Hausner ratio of the powder composition may be from 1.10 to 1.30, such as from 1.20 to 1.29, such as from greater than 1.20 to 1.28, such as from greater than 1.25 to 1.27.

[0025] The present invention further relates to a method for preparing one of the powder compositions disclosed herein, the method comprising grinding the cemented carbide particles and the metal binder, polymer binder, and solvent to form a mixture; spray drying the mixture to form a powder; sintering the powder; grinding and sieving the powder; and sintering the powder a second time in a partially liquid state to form the powder composition.

[0026] The density and individual particle porosity of the powder composition disclosed herein can be achieved by applying one or more sintering processes to the particles. The sintering process can be performed without using a sintering inhibitor to reduce particle sticking or adhesion. The sintered carbide particle characteristics described herein can be achieved in the absence of a sintering inhibitor. Sintered carbide particles can be prepared by sintering the grade powder composition at a temperature of 1100° C. to 1325° C. for 0.5 to 2 hours to provide a sintered compact. The sintered compact is then ground to provide individual sintered carbide particles. Depending on the particle morphology and density, the sintered carbide particles can be further heat treated to further densify. The further heat treatment can include plasma densification, such as plasma spheroidization using an RF plasma torch or a DC plasma torch. Alternatively, the sintered carbide particles can be re-sintered to form a second compact. The second compact is ground to provide sintered carbide particles. Any desired number of additional densification treatments may be applied to provide sintered cemented carbide particles having a desired apparent density, tap density, and / or individual particle density. The sintering time and temperature may be selected based on several considerations, including but not limited to the binder content of the cemented carbide particles, the desired sintered particle density, and the sintering stage. In some embodiments, an early sintering stage is performed at a lower temperature and / or for a shorter time to aid in grinding the sintered compact. For example, an initial or early sintering process may be applied at a temperature below the liquefaction temperature of the binder. A later or final sintering process may reach a higher temperature, such as a temperature at which liquid phase sintering occurs.

[0027] The present invention also relates to a binder jet-printed sintered cemented carbide body comprising sintered cemented carbide particles having a D50 greater than 12 μm and a D10 greater than 5 μm, wherein the sintered cemented carbide particles contain 9 wt% to 11 wt% of a metal binder based on the total weight of the sintered cemented carbide particles, wherein the sintered cemented carbide body has a theoretical density percentage equal to or greater than 99%.

[0028] When the carbide comprises tungsten carbide and the metallic binder comprises cobalt, the vacuum sintered density of the sintered cemented carbide body may be greater than or equal to 13.75 g / cm 3 , such as at least 13.8 g / cm 3 , such as at least 13.9 g / cm 3 , such as 14.0 g / cm 3 The vacuum sintered density can be measured by ASTM B311 density determination for powder metallurgy materials containing less than 2% porosity.

[0029] When the carbide comprises tungsten carbide and the metallic binder comprises cobalt, the sintered HIP density of the sintered cemented carbide body may be equal to or greater than 14 g / cm 3 , such as at least 14.1 g / cm 3 , such as at least 14.2 g / cm 3 , such as at least 14.3 g / cm 3 , such as about 14.4 g / cm 3 The sintered HIP density can be measured by ASTM B311 density determination for powder metallurgy materials containing less than 2% porosity.

[0030] The theoretical density percentage of the sintered cemented carbide body can be equal to or greater than 99%, such as greater than 99.1%, such as greater than 99.3%, such as greater than 99.5%, such as greater than 99.7%, such as greater than 99.9%. The theoretical density percentage is calculated by dividing the sintered HIP density as measured by ASTM B311 by the reference density. As used herein, "theoretical density" means the maximum achievable density of the sintered cemented carbide body.

[0031] The sintered porosity grade of the sintered cemented carbide body may be A02B00C00, A01B00C00, or A00B00C00. The sintered porosity grade may be determined by the procedure of ASTM B276: Standard Test Method for Apparent Porosity in Active-Only Cemented Carbides.

[0032] The present invention further relates to a method for forming a sintered cemented carbide body, the method comprising: binder jetting a powder composition comprising sintered cemented carbide particles, the sintered cemented carbide particles having a D50 greater than 12 μm and a D10 greater than 5 μm, the sintered cemented carbide particles comprising 9 wt% to 11 wt% of a metal binder based on the total weight of the sintered cemented carbide particles, and the sintered cemented carbide particles having an apparent density of 3.0 g / cm 3 Up to 6.0 g / cm 3 , and the sintered cemented carbide particles have a printing binder to form a green body; and sintering the green body to provide the sintered cemented carbide body. Any of the powder compositions disclosed above can be used to form a sintered cemented carbide body.

[0033] The green body is formed by binder jetting one of the powder compositions described herein and a printing binder. Any organic binder known in the art can be used as the printing binder. In one embodiment, the organic binder can include one or more polymeric materials, such as polyvinylpyrrolidone (PVP), polyethylene glycol (PEG), or a mixture thereof. The organic binder can be curable, which can enhance the strength of the green body. The polymeric binder can be an aqueous binder or a solvent binder. The green body can exhibit a binder saturation of at least 80%, such as 100% or greater.

[0034] The green body can then be sintered under conditions and for a period sufficient to provide a sintered body having the desired density. The green article can be vacuum sintered or sintered under a hydrogen or argon atmosphere at a temperature between 1300°C and 1560°C. Furthermore, the sintering time can typically range from 10 minutes to 5 hours. Hot isostatic pressing (HIP) can optionally be added to the sintering process. HIP can be performed as a post-sintering operation or applied during vacuum sintering. HIP can be applied at a pressure of 1 MPa to 300 MPa and a temperature of 1300°C to 1560°C for up to 2 hours. The microstructure of the sintered cemented carbide body can be uniform. The sintered cemented carbide body can exhibit volume shrinkage in the sintered sample compared to a 60 to 70 volume percent pre-printed sample.

[0035] The sintered cemented carbide bodies produced according to the methods described herein can be used in a variety of industries, including petrochemical, automotive, aerospace, industrial tool processing, metal cutting tools and manufacturing. The sintered cemented carbide bodies can be used as parts exposed to wear environments or abrasive operating conditions, such as flow control parts, pumps, bearings, valves, valve parts, centrifuge parts, disk stacks and / or fluid handling parts. The sintered cemented carbide bodies can also include one or more internal fluid flow channels formed by additive manufacturing techniques. The sintered cemented carbide bodies can be near net shape and / or require minimal post-sintering processing to place the body in its final form.

[0036] Examples

[0037] A spherical porous powder (C1) was produced by grinding a mixture of 90 wt.% tungsten carbide (WC) particles, 10 wt.% cobalt (Co) powder and organic additives. The slurry was then spray dried and heated at 1225°C to 1275°C in the solid state under vacuum (< 10 -3The powder was sintered in a vacuum oven (< 10-3 Torr) for 1-2 hours to form a slightly sintered powder. The sintered powder was ground and sieved to achieve the desired powder size distribution. A spherical dense powder (C2) was produced by re-sintering the GU1 powder at 1280°C to 1330°C in a partially liquid state in a vacuum oven (< 10-3 Torr) for 1-2 hours to increase the density. Figure 1 and 2 Scanning electron microscope (SEM) images of the cross sections of C1 and C2 are provided in , respectively.

[0038] Table 1 shows the powder particle size distribution (D10, D50, and D90), porosity, and morphology of the C1 and C2 powders. The powder particle size distribution was measured using a laser diffraction particle size analyzer (S-3500, commercially available from Mackey Claytsch). Powder samples were mounted, polished, and imaged to characterize porosity and morphology. Image J software was used to calculate porosity from SEM images.

[0039] Table 1

[0040] Characteristics of powder compositions

[0041]

[0042] Test specimens measuring 25 mm x 25 mm x 7 mm and 11 mm x 11 mm x 31 mm were printed from either C1 or C2 using a binder jetting machine, the "Desktop P1," with water-based SPJ-04 binder. For this particular binder type, the binder droplet size on the Desktop P1 printer was estimated to be approximately 20 pL. Layer thickness was 75 μm, and average binder saturation ranged from 30% to 60%, as reported in Table 2.

[0043] The test specimens were cured in an argon atmosphere at 195°C in a curing oven for 4 hours. After curing, de-powdering was performed by removing the surrounding unbonded powder using vacuum. The samples were then placed on a graphite tray coated with a graphite-based release agent for debonding and sintering in a sintering-HIP furnace. In the debonding step, the samples were heated to 538°C in a hydrogen atmosphere. In the subsequent sintering step, the samples were sintered in argon at a temperature of 1440-1510°C and a pressure of 3.4-5.5 MPa for 45 minutes. A shrinkage of 60 vol.% to 70 vol.% was observed in the sintered samples compared to the pre-printed samples. The sintered density of the sintered samples was 14.4 g / cm according to ASTM B276 standard. 3 , and the porosity grade is A02B00C00 or lower. The results are provided in Table 2.

[0044] Table 2

[0045] Characteristics of WC-10Co samples.

[0046]

[0047] 1 Reference density 14.42 g / cm 3

[0048] Surprisingly, the powder compositions of the present invention can achieve high sintered densities and excellent porosity levels, as demonstrated by the data provided in Table 2. Notably, powder compositions comprising only 10 wt% cobalt, based on the total weight of the powder composition, achieve excellent sintering properties.

[0049] For the purpose of this specific embodiment, it should be understood that, unless clearly indicated otherwise, the present invention can take various alternatives and step sequences. In addition, except in any operating examples or when otherwise indicated, all numerals expressing the quantity of the components used in the present specification and claims should be understood to be modified by the term "about" in all cases. Therefore, unless indicated otherwise, the numerical parameters set forth in the following description and the appended claims are approximate values that can vary according to the desired properties to be obtained by the present invention. At least, and without attempting to limit the application of the doctrine of equivalents to the scope of the claims, each numerical parameter should at least be interpreted according to the number of reported significant figures and by applying ordinary rounding techniques.

[0050] Notwithstanding that the numerical ranges and parameters setting forth the broad scope of the invention are approximations, the numerical values set forth in the specific examples are reported as precisely as possible. Any numerical value, however, inherently contains certain errors necessarily resulting from the standard deviation found in their respective testing measurements.

[0051] Furthermore, it should be understood that any numerical range recited herein is intended to include all subranges contained therein. For example, a range of "1 to 10" is intended to include all subranges between (and including) the recited minimum value of 1 and the recited maximum value of 10, i.e., having a minimum value equal to or greater than 1 and a maximum value equal to or less than 10.

[0052] As used herein, "including," "containing," and similar terms are understood in the context of this application to be synonymous with "comprising," and are thus open-ended and do not exclude the presence of additional, undescribed or unrecited elements, materials, ingredients, or method steps. As used herein, "consisting of" is understood in the context of this application to exclude the presence of any unspecified elements, ingredients, or method steps. As used herein, "consisting essentially of" is understood in the context of this application to include the specified elements, materials, ingredients, or method steps "as well as those that do not materially affect the basic and novel characteristics described."

[0053] In this application, unless specifically stated otherwise, the use of the singular includes the plural and the plural encompasses the singular. For example, although reference is made herein to "a" powder composition, "a" cemented carbide body, and "an" apparent density, combinations (i.e., a plurality) of these components may be used.

[0054] Additionally, in this application, the use of "or" means "and / or" unless specifically stated otherwise, even though "and / or" may be explicitly used in certain circumstances.

[0055] While specific aspects of the present invention have been described in detail, it will be appreciated by those skilled in the art that various modifications and alternatives to those details can be developed based on the overall teachings of this disclosure. Therefore, the particular arrangements disclosed are intended to be illustrative only and not limiting of the scope of the invention, which is to be given by the full scope of the appended claims and any and all equivalents thereof.

Claims

1. A powder composition for binder jet printing, the powder composition comprising sintered cemented carbide particles, the D50 of the sintered cemented carbide particles being greater than 12 μm, the D10 of the sintered cemented carbide particles being greater than 5 μm, and the sintered cemented carbide particles comprising 9 wt % to 11 wt % of a metal binder based on the total weight of the sintered cemented carbide particles, wherein the powder composition has an apparent density of 3.0 g / cm 3 Up to 6.0 g / cm 3 . 2 . The powder composition of claim 1 , wherein the sintered cemented carbide particles comprise tungsten carbide and the metallic binder comprises cobalt. 3 . The powder composition of claim 1 , comprising 9.5 to 10.5 wt % of the metallic binder, based on the total weight of the sintered cemented carbide particles.

4. The powder composition of claim 1, wherein the D50 is at least 14 μm. The powder composition according to claim 1 , wherein the D50 is greater than 12 μm to 16 μm. The powder composition according to claim 1 , wherein the D10 is greater than 5 μm to 10 μm.

7. The powder composition of claim 1, wherein the D10 is at least 7 μm.

8. The powder composition of claim 1, wherein the D90 of the sintered cemented carbide particles is less than 30 μm. 9 . The powder composition according to claim 1 , wherein the D90 is from 10 μm to less than 30 μm.

10. The powder composition of claim 1, wherein the sintered cemented carbide particles have a particle porosity of less than 20% by volume.

11. The powder composition of claim 1 , wherein the sintered cemented carbide particles are substantially spherical.

12. The powder composition according to claim 1, wherein the tap density of the powder composition is 3.0 g / cm 3 Up to 6.0 g / cm 3 .

13. The powder composition of claim 1, wherein the powder composition has a Hausner Ratio greater than 1.

20.

14. A method for preparing the powder composition according to claim 1, the method comprising: grinding the carbide particles and the metal binder, polymer binder, and solvent to form a slurry; spray drying the slurry to form a powder; sintering the powder; grinding and sieving the powder; and The powder is sintered a second time in a partially liquid state to form the powder composition.

15. A method of preparing a powder composition for binder jet printing, the method comprising: grinding metal carbide particles and a metal binder to form a slurry; spray drying the slurry to form a powder; sintering the powder; grinding and sieving the powder; and Sintering the powder in a partially liquid state to form the powder composition, wherein the sintered powder comprises sintered cemented carbide particles, the D50 of the sintered cemented carbide particles being greater than 12 μm, the D10 of the sintered cemented carbide particles being greater than 5 μm, and the apparent density of the sintered cemented carbide particles being 3.0 g / cm 3 Up to 6.0g / cm 3 , and the sintered cemented carbide particles include 9 wt % to 11 wt % of the metal binder based on the total weight of the cemented carbide particles.

16. A binder jet printed sintered cemented carbide body comprising sintered cemented carbide particles having a D50 greater than 12 μm and a D10 greater than 5 μm, the sintered cemented carbide particles comprising 9 wt% to 11 wt% metal binder based on the total weight of the sintered cemented carbide particles, wherein the sintered cemented carbide body has a percent theoretical density equal to or greater than 99%.

17. The sintered cemented carbide body of claim 16, wherein the sintered cemented carbide body comprises tungsten carbide and cobalt, and wherein the sintered cemented carbide body has a sintered density greater than 14.0 g / cm 3 .

18. The sintered cemented carbide body of claim 17, wherein the metallic binder comprises cobalt and the sintered cemented carbide body has a sintered density greater than 14.3 g / cm 3 .

19. The sintered cemented carbide body of claim 16, comprising 9.5 to 10.5 weight percent of the metallic binder based on the total weight of the sintered cemented carbide particles.

20. The sintered cemented carbide body of claim 16, wherein the D50 is at least 14 μm.

21. The sintered cemented carbide body of claim 16, wherein the D50 is greater than 12 μm to 16 μm.

22. The sintered cemented carbide body of claim 16, wherein the D10 is at least 7 μm.

23. The sintered cemented carbide body of claim 16, wherein the sintered cemented carbide particles have a D90 of less than 30 μm.

24. The sintered cemented carbide body of claim 16, wherein the sintered cemented carbide body has a sintered porosity grade of A02B00C00, A01B00C00, or A00B00C00.

25. A method of forming a sintered cemented carbide body according to claim 16, the method comprising: binder jet printing a powder composition comprising the sintered cemented carbide particles to form a green body; and The green body is sintered to produce the sintered cemented carbide body.

26. A method of forming a sintered cemented carbide body, the method comprising: Binder jet printing is performed on a powder composition comprising sintered cemented carbide particles, wherein the sintered cemented carbide particles have a D50 greater than 12 μm and a D10 greater than 5 μm, the sintered cemented carbide particles comprising 9 wt % to 11 wt % of a metal binder based on the total weight of the sintered cemented carbide particles, and the sintered cemented carbide particles have an apparent density of 3.0 g / cm 3 Up to 6.0 g / cm 3 , and the sintered cemented carbide particles have a printed binder to form a green body; and The green body is sintered to provide the sintered cemented carbide body.

27. The method of claim 26, wherein the green body is sintered by a sinter-HIP process.

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