Self-neutron shielding cemented carbides

Abstract

Provided is a self-neutron shielding high density cemented carbide composition including a ceramic hard phase constituted of tungsten carbide (WC), sub-stoichiometric ditungsten carbide (W2C), or a combination thereof, an iron (Fe)-chromium (Cr) based metallic binder phase present in an amount of from about 0.20 wt.% to about 15.00 wt.% based on a total weight of the cemented carbide composition with a Cr amount in a range of from about 2 wt.% to about 18 wt.% based on a total weight of the Fe-Cr based metallic binder phase, and a boron concentration gradient. Associated methods of making a self-neutron shielding high density cemented carbide are further presented.

Description

SELF-NEUTRON SHIELDING CEMENTED CARBIDES FIELD OF THE DISCLOSURE

[0001] The present disclosure relates to self-neutron shielding high densitycemented carbide compositions, and to associated methods of preparing self-neutronshielding high density cemented carbides. BACKGROUND

[0002] When designing any type of nuclear reactor, it is elementary that the pointof focus is to consider how the reactor components should be protected from themagnitude of the neutron flux, and the gamma rays generated in the nuclear reactorduring fission, and the fusion reactions. A prerequisite is that the shielding materialshould be tailored to provide protection against a wide range of highly energeticradioactive radiation species including, e.g., α-particles, β-particles, γ-rays, and neutronsover a short distance. These conditions place strict restrictions on the type of materials,which can be used during the designing stages of a nuclear reactor. It is also key thatthe material forming the shielding itself is resistant to activation and does not itselftransform to other harmful radioisotopes when being irradiated during the fission, and thefusion reactions. This means that materials containing significant quantities of, e.g., nickel(Ni) and cobalt (Co) generally cannot be used for this purpose, since these pose activationhazards when being irradiated, as they undesirably possess extremely long radioactivehalf-lives for elimination from the environment.

[0003] Small modular fusion nuclear reactors, and magnetic confinement reactorshave emerged as popular choices of use for next generation nuclear power plants. At itscore, small modular nuclear plants favorably possess the potential benefit of being safer,and more efficient than the large nuclear power plants that are currently in use. On thedownside, in the case of for example magnetic confinement fusion reactors, these arereliant on cryogenically cooled copper and / or High Temperature Superconductors (HTS)to generate a magnetic field. Thus, the space between the plasma chamber, and the coldconductors (copper / HTS) is rather limited. In both cases, these types of reactors pose achallenge when considering the choice of material for radiation shielding, since the geometry of such reactors means that space is indeed rather limited. In consequence ofthis, the shielding material must logically be applied in thin layers, while still maintainingthe neutron shielding capacity.

[0004] Therefore, the challenge is to find an alternative shielding material that doesnot need to be applied in excessively large thicknesses to achieve a satisfactory shielding effect. Moreover, the material should ideally also not form any hazardous by-productsfrom the exposure to the nuclear fission, and the fusion processes after having beenirradiated. It is therefore key that the materials cannot be constituted of elements, whichwould transmute to multiple harmful radionuclides exhibiting a significantly long half-life,such that it would impede the decommissioning, and refueling stages of the nuclearreactor at the end of a duty cycle. What is more, a core aspect, is that it should also bepossible to prepare the materials to be used for this application using conventionaltechniques without involving multiple cumbersome cycles and steps.

[0005] The most attractive materials in this regard would be high-density materialsfurther with the capacity of displaying high corrosion resistance and oxidation resistance.Hence, it is crucial that neutron shielding materials for nuclear applications exhibit a highdensity to efficaciously quell by capturing the neutron fluxes produced in the nuclearreactors. Apart from this, they should be constituted of elements having a shortradioactive half-life after having been irradiated during the fission, and the fusion reactionsto avoid complex decommissioning procedures at the end of the reactor’s lifecycle. Lastly, as stated, it is instrumental that they should be corrosion-resistant and oxidation- resistant.

[0006] Further taking the foregoing into account, boron is an effective absorber oflow energy neutrons, which may be able to otherwise penetrate a tungsten-based shield.The presence of boron thus improves the shielding property of the material duringoperation. Further, additional advantages of employing boron are at least manifold. First,boron is self-shielding for the safe handling, and the disposal of the parts at the end ofthe reactor’s life. Second, the presence of boron will also help to enhance the sinteringcapability of the material by reducing the melting point of the metallic binder, thus reducingpotential complexity during sintering. Third, the boron treatment operation provides thefreedom of choice of introducing the boron directly into the sintering tray, or the sinteringmould, which boron is thus used as a pressing and a sintering media. Moreover, theboron can be coated onto an outer surface of the green body, or onto an outer surface ofthe sintered cemented carbide parts. This favorably allows both the formation of a boronconcentration gradient on the outer surface of the treated green body during the sinteringprocess, or the outer surface of the sintered cemented carbide parts by diffusion, and theprotection of the material from reaction with the graphite from the furnace.

[0007] International patent publication WO2018206174A1, which is incorporatedherein by reference in its entirety, relates to cemented carbides including an iron-chromium (Fe-Cr)-based metallic binder employed for making a cutting tool, a wear part,a seal ring, a bushing, a component of an automotive, a die, or a tool for handlingradioactive material. However, the Cr amount in the binder in international patentpublication WO2018206174A1 is only present in a range of from 1 wt.% to 10 wt.%, thusfailing to provide a substantially continuous Cr3O2 passive layer in the binder phase forcorrosion-protective purposes. Moreover, the use of sub-stoichiometric ditungstencarbides, like for instance W2C to additionally increase the material density, is likewisenot disclosed in international patent publication WO2018206174A1.

[0008] International patent publication WO2022 / 136470, which is furtherincorporated herein by reference in its entirety, relates to the use of di-tungsten penta- boride, W2B5, within a neutron shield. Notwithstanding this, the formed materials described in international patent publication WO2022 / 136470 all exhibit significantly lower densities compared to, for example, tungsten carbide (WC), and sub-stoichiometric ditungsten carbide (W2C). This unfavorably limits their potential neutron absorbing, and quelling capability.

[0009] Thus, taking the entirety of the foregoing into consideration, there istherefore a need for self-neutron shielding high density cemented carbide compositionsdemonstrating improved corrosion-resistance, and an acceptably short radioactive half-life activity for neutron shielding in nuclear reactors.SUMMARY

[0010] Provided is a self-neutron shielding high density cemented carbidecomposition including a ceramic hard phase, an iron (Fe)-chromium (Cr) based metallicbinder phase present in an amount of from about 0.20 wt.% to about 15.00 wt.% basedon a total weight of the cemented carbide composition with a Cr amount in a range offrom about 2 wt.% to about 18 wt.% based on a total weight of the Fe-Cr based metallicbinder phase, and a boron concentration gradient.

[0011] Optionally, the ceramic hard phase includes tungsten carbide (WC), sub-stoichiometric ditungsten carbide (W2C), or a combination thereof.

[0012] Optionally, the ceramic hard phase includes WC.

[0013] Optionally, the ceramic hard phase includes sub-stoichiometric W2C.

[0014] Optionally, the ceramic hard phase includes a combination of WC and sub-stoichiometric W2C in a ratio of from about 4:1 to about 15:1.

[0015] Optionally, the self-neutron shielding high density cemented carbidecomposition may include from about 85.00 wt.% to about 99.80 wt.% of the ceramic hardphase based on a total weight of the cemented carbide composition.

[0016] Optionally, the Fe-Cr based metallic binder phase is made by blending (i) aFeCr powder with a Cr3C2 powder, (ii) a Fe powder with a Cr3C2 powder, or (iii) a Fepowder with a Cr powder.

[0017] Optionally, the cemented carbide composition has an HV1 Vickershardness in a range of from about 1430 HV1 to about 2045 HV1.

[0018] Also provided is a method of making a sintered self-neutron shielding highdensity cemented carbide, including blending a powder mixture in a milling liquid comprising powders forming hard constituents of a ceramic hard phase and an iron (Fe)-chromium (Cr) based metallic binder phase present in an amount of from about 0.20 wt.%to about 15.00 wt.% with a Cr amount in a range of from about 2 wt.% to about 18 wt.%based on a total weight of the Fe-Cr based metallic binder phase, with an organic binder to form a slurry blend. The formed slurry blend is next dried, followed by undergoingcompaction to form a green body. The green body is next coated with a boron-containingagent on its outer surface, which may be boron or boron nitride (BN) or a combinationthereof, and is finally sintered to form a boron concentration gradient on the outer surfaceof the green body.

[0019] Further provided is a method of making a sintered cemented carbide,comprising: blending a powder mixture in a milling liquid comprising powders forming hard constituents of a ceramic hard phase and an iron (Fe)-chromium (Cr) based metallicbinder phase present in an amount of from about 0.20 wt.% to about 15.00 wt.% havinga Cr amount in a range of from about 2 wt.% to about 18 wt.% based on a total weight ofthe Fe-Cr based metallic binder phase, with an organic binder to form a slurry blend. The formed slurry blend is next dried, followed by undergoing compaction to form a green body. The formed green body is sintered to form the cemented carbide, which is followed by coating an outer surface of the sintered cemented carbide with a boron-containingagent, which may be boron or boron nitride (BN) or a combination thereof, to form a boronconcentration gradient on the outer surface of the sintered cemented carbide by heattreatment at a temperature range of from about 1200°C to about 1800°C.

[0020] Optionally, drying the slurry blend includes vacuum drying, air drying, freezedrying, or spray drying through atomization.

[0021] Optionally, the sintering includes at least hot pressing (HP), hot isostaticpressing (HIP), spark plasma sintering (SPS), vacuum sintering, high pressure sintering(sinter-HIP), or high-pressure high temperature (HPHT) sintering.

[0022] Other systems, methods, features and advantages will be, or will becomeapparent to one with skill in the art upon examination of the following figures and detailed description. It is intended that all such additional systems, methods, features and advantages be included within this description, be within the scope of the present disclosure, and be protected by the following claims. Nothing in this section should be taken as a limitation on those claims. Further aspects and advantages are discussedbelow in conjunction with the examples of the disclosure. It is to be understood that boththe foregoing general description and the following detailed description of the present disclosure are examples and explanatory and are intended to provide further explanation of the disclosure as claimed. BRIEF DESCRIPTION OF THE DRAWING

[0023] The accompanying drawing, which is included to provide a furtherunderstanding of the subject matter and is incorporated in and constitutes a part of this specification, illustrates implementations of the subject matter and together with thedescription serves to explain the principles of the disclosure.

[0024] FIG. 1 is a flow diagram showing the individual steps in spray-drying byatomization in the preparation of a self-neutron shielding high density cemented carbide in accordance with the present subject matter.

[0025] FIG. 2A shows the green body of the self-neutron shielding high densitycemented carbide before an outer surface of the green body has been subjected to boroncoating in accordance with the present subject matter.

[0026] FIG. 2B shows the green body of the self-neutron shielding high densitycemented carbide after an outer surface of the green body has been subjected to boroncoating in accordance with the present subject matter.

[0027] FIG.3A is a flow diagram showing the individual process steps of preparinga self-neutron shielding high density cemented carbide in accordance with the presentsubject matter.

[0028] FIG.3B is a flow diagram showing the individual process steps of preparinga self-neutron shielding high density cemented carbide in accordance with the present subject matter.

[0029] FIG. 4A shows the HV1 Vickers hardness as a function of the boronizationdistance to the surface (mm) for a boronized sample having a composition of 90.20 wt.%tungsten carbide (WC), 9.31 wt.% iron (Fe), and 0.45 wt.% chromium (Cr) in accordancewith the present subject matter.

[0030] FIG. 4B shows the HV1 Vickers hardness as a function of the boronizationdistance to the surface (mm) for a boronized sample having a composition of 89.00 wt.%tungsten carbide (WC), 8.82 wt.% iron (Fe), and 1.91 wt.% chromium (Cr) in accordancewith the present subject matter.

[0031] FIG. 4C shows the HV1 Vickers hardness as a function of the boronizationdistance to the surface (mm) for a boronized sample having a composition of 85.40 wt.%tungsten carbide (WC), 12.35 wt.% iron (Fe), and 1.99 wt.% chromium (Cr) in accordancewith the present subject matter.

[0032] FIG. 4D shows the HV1 Vickers hardness as a function of the boronizationdistance to the surface (mm) for a boronized sample having a composition of 85.00 wt.% tungsten carbide (WC), 14.36 wt.% iron (Fe), and 0.60 wt.% chromium (Cr) in accordancewith the present subject matter.

[0033] FIG. 5A shows a potentiodynamic scan for a boronized, and a non-boronized sample having a composition of 90.20 wt.% tungsten carbide (WC), 9.31 wt.% iron (Fe), and 0.45 wt.% chromium (Cr) in accordance with the present subject matter.

[0034] FIG. 5B shows a potentiodynamic scan for a boronized, and a non-boronized sample having a composition of 89.00 wt.% tungsten carbide (WC), 8.82 wt.%iron (Fe), and 1.91 wt.% chromium (Cr) in accordance with the present subject matter.

[0035] FIG.6A shows a potentiodynamic scan comparison for a boronized samplehaving a composition of 90.20 wt.% tungsten carbide (WC), 9.31 wt.% iron (Fe), and 0.45wt.% chromium (Cr) with a boronized sample having a composition of 89.00 wt.%tungsten carbide (WC), 8.82 wt.% iron (Fe), and 1.91 wt.% in accordance with the present subject matter.

[0036] FIG.6B shows a potentiodynamic scan comparison for a boronized samplehaving a composition of 85.00 wt.% tungsten carbide (WC), 14.36 wt.% iron (Fe), and0.60 wt.% chromium (Cr) with a boronized sample having a composition of 90.20 wt.%tungsten carbide (WC), 9.31 wt.% iron (Fe), and 0.45 wt.% chromium (Cr) wt.% inaccordance with the present subject matter.

[0037] FIG.6C shows a potentiodynamic scan comparison for a boronized samplehaving a composition of 85.40 wt.% tungsten carbide (WC), 12.35 wt.% iron (Fe), and1.99 wt.% chromium (Cr) with a boronized sample having a composition of 85.00 wt.%tungsten carbide (WC), 14.36wt.% iron (Fe), and 0.60 wt.% chromium (Cr) wt.% inaccordance with the present subject matter. DETAILED DESCRIPTION

[0038] Unless defined otherwise all technical and scientific terms used herein havethe same meaning as commonly understood to one of ordinary skill in the art to which the presently described subject matter pertains.

[0039] Where a range of values is provided, for example, concentration ranges,percentage ranges, or ratio ranges, it is understood that each intervening value, to the tenth of the unit of the lower limit, unless the context clearly dictates otherwise, between the upper and lower limit of that range and any other stated or intervening value in that stated range, is encompassed within the described subject matter. The upper and lower limits of these smaller ranges may independently be included in the smaller ranges, andsuch examples are also encompassed within the described subject matter, subject to anyspecifically excluded limit in the stated range. Where the stated range includes one or both of the limits, ranges excluding either or both of those included limits are also included in the described subject matter.

[0040] The following definitions set forth the parameters of the described subjectmatter.

[0041] As used herein this disclosure, the term “self-neutron shielding high densitycemented carbide” generally refers to a composite material constituted of, (I)a ceramic hard phase generally constituted herein of tungsten carbide (WC), sub-stoichiometric ditungsten carbide (W2C), or a mixture thereof in a ratio of the WC:W2Cbeing from about 4:1 to about 15:1, such as e.g. from about 6:1 to about 15:1, from about7:1 to about 15:1, from about 8:1 to about 15:1, from about 9:1 to about 15:1, from about10:1 to about 15:1, from about 11:1 to about 15:1, from about 12:1 to about 15:1, from about 13:1 to about 15:1, from about 14:1 to about 15:1, from about 6:1 to about 8:1, from about 7:1 to about 8:1, from about 6:1 to about 10:1, from about 7:1 to about 10:1, fromabout 8:1 to about 10:1, from about 9:1 to about 10:1, from about 6:1 to about 12:1, fromabout 7:1 to about 12:1, from about 8:1 to about 12:1, from about 9:1 to about 12:1, fromabout 10:1 to about 12:1, from about 11:1 to about 12:1, in a ratio of 1:1, in a ratio of 2:1,in a ratio of 3:1, in a ratio of 4:1, or in a ratio of 5:1 anchored and cemented by, (II) a Fe-Cr based metallic binder matrix (i.e. thus creating a Fe-Cr based metallic binder phase),which Fe-Cr based metallic binder is typically used in a weight from about 0.20 wt.% toabout 15.00 wt.% based on the total weight of the cemented carbide, with a Cr amountranging from about 2 wt.% to about 18 wt.% based on the total weight of the Fe-Cr basedmetallic binder. As used herein this disclosure, the term “sub-stoichiometric” refers to aW / C ratio being substantially greater than 1. The ceramic hard phase powder, and theFe-Cr based metallic binder phase powder can be processed into a wide variety ofdifferent microstructures that achieve different mechanical, and physical properties.Moreover, additional components can be added to the composition to help control, andfurther to refine the properties achieved by cemented carbide compositions. Bycontrolling various parameters including grain size, Fe-Cr content, dotation (i.e., alloycarbides), and carbon content, a cemented carbide manufacturer can favorably tailor anddirect its performance to specific and unique applications. A cemented carbide is ideallydesigned to provide the physical optimal properties of both a ceramic, such as a hightemperature-resistance and a great hardness, and those of a soft ductile metal, such asthe capability to undergo plastic deformation, and provide good fracture toughness. Thenaturally ductile soft Fe-Cr metal binder serves to offset the characteristic brittle behaviorof the ceramic hard phase, and thus raises its associated fracture toughness, anddurability. The ceramic hard phase of the cemented carbide is generally composed ofrefractory carbides of metals, such as, but not limited to most typically tungsten, howeveralternatively titanium, tantalum, chromium, vanadium, or any combinations thereof. Theceramic hard phase can be present in the cemented carbide powder in any possible combination having the mentioned metals, and in a weight that is not inconsistent andincompatible with the objectives of the present subject matter. To qualify as a self-neutron shielding high density cemented carbide herein this disclosure, a cemented carbidegenerally has a ceramic hard phase constituted of at least about 85.00 wt.% to about99.80 wt.% based on the total weight of the cemented carbide.

[0042] As used herein this disclosure, “wt.%” refers to a given weight percent (I)based on a total weight of a self-neutron shielding high density cemented carbidecomposition, or (II) based on a total weight of a Fe-Cr based metallic binder phase. When“wt.%” is mentioned in the disclosure or in the claims, it will also explicitly be mentioned,whether it refers to a given weight percent of (I), or (II) in each given particular scenario.In the method claims herein this disclosure, “wt.%” refers to a given weight percent based on a total weight of the final sintered cemented carbide, and not the powder mixture.

[0043] As used herein this disclosure, the term “D50” refers to a particle sizecorresponding to 50% of the volume of the sampled particles being smaller than and 50% of the volume of the sampled particles being greater than the recited D50 value. Similarly,the term “D90” refers to a particle size corresponding to 90% of the volume of the sampledparticles being smaller than and 10% of the volume of the sampled particles being greaterthan the recited D90 value. The term “D10” refers to a particle size corresponding to 10%of the volume of the sampled particles being smaller than and 90% of the volume of the sampled particles being greater than the recited D10 value. A width of the particle size distribution can be calculated by determining the span, which is defined by the equation (D90-D10) / D50. The span gives an indication of how far the 10 percent and the 90 percent points are apart normalized with the midpoint.

[0044] As used herein this disclosure, the term “about” is meant to mean plus orminus 5% of the numerical value of the number with which it is being used in the claimsand herein this disclosure. Thus, “about” may be used to provide flexibility to a numericalrange endpoint, in which, a given value may be “above” or “below” the given value. As such, for example a value of 50% may be intended to encompass a range, which may be defined by for example ranges like 47.5%-52.25%, 47.5%-52.5%, 47.75%-50%, 50%-52.5%, 48%-48.5%, 48%-48.75%, 48%-49%, 48%-49.5%, 48%-49.75%, 48%-50%,48%-50.25%, 48%-50.5%, 48%-50.75%, 48%-51%, 48%-51.5%, 48%-51.75%, 48%- 52%, 48%-52.25%, 48%-52.5%, 48.25%-48.5%, 48.25%-48.75%, 48.25%-49%, 48.25%- 49.5%, 48.25%-49.75%, 48.25%-50%, 48.25%-50.25%, 48.25%-50.5%, 48.25%- 50.75%, 48.25%-51%, 48.25%-51.25%, 48.25%-51.5%, 48.25%-51.75%, 48.25%-52%, 48.25%-52.25%, 48.25%-52.5%, 48.5%-48.75%, 48.5%-49%, 48.5%-49.5%, 48.5%- 49.75%, 48.5%-50%, 48.5%-50.25%, 48.5%-50.5%, 48.5%-50.75%, 48.5%-51%, 48.5%- 51.25%, 48.5%-51.5%, 48.5%-51.75%, 48.5%-52%, 48.5%-52.25%, 48.5%-52.5%, 49%- 49.25%, 49%-49.5%, 49%-49.75%, 49%-50%, 49%-50.25%, 49%-50.5%, 49%-50.75%, 49%-51%, 49%-51.25%, 49%-51.5%, 49%-51.75%, 49%-52%, 49%-52.25%, 49%- 52.5% 49.5%-49.75%, 49.5%-50%, 49.5%-50.25%, 49.5%-50.5%, 49.5%-50.75%, 49.5%-51%, 49.5%-51.5%, 49.5%-51.75%, 49.5%-52%, 49.5%-52.25%, 49.5%-52.5%, 49.75%-50%, 49.75%-50.25%, 49.75%-50.5%, 49.75%-50.75%, 49.75%-51%, 49.75%- 51.25%, 49.75%-51.5%, 49.75%-51.75%, 49.75%-52%, 49.75%-52.25%, 49.75%- 52.5%, 50%-50.25%, 50%-50.5%, 50%-50.75%, 50%-51%, 50%-51.25%, 50%-51.5%, 50%-52%, 50%-52.25%, 50%-52.5% etc.

[0045] As used herein this disclosure, the term “sintering” refers to a process,where heating under a controlled pressure is conducted to minimize the surface area of a particulate system, which is associated with generation of bonds between neighboring small particles or granules, and subsequent shrinkage of the aggregated particles orgranules. Densification of a dense solid bulk mass is performed by heating the particlesunder a controlled pressure. As used herein, the term “ambient conditions” refer to a temperature of 25º C, 298.15 K and a pressure of 101.325 kPa.

[0046] As used herein this disclosure, the term “particle” refers to a discrete bodyor bodies.

[0047] As used herein this disclosure, the term “porosity” is defined by the degree,whereby a given material has a hole, a void, or a space.

[0048] Wherever used throughout the disclosure, the term “generally” has themeaning of “typically” or “closely” or “within the vicinity or range of”.

[0049] As used herein this disclosure, the term “substantially” refers to thecomplete or nearly complete extent or degree of an action, characteristic, property, state, structure, item, or result.

[0050] As used herein, “spherical” refers to the grains having a substantially“round” shape.

[0051] As used herein this disclosure, the term “fracture toughness” i.e., (KIc),refers to the ability of a material with pre-cracks to resist further fracture propagation uponabsorbing energy. Fracture toughness (KIc) is calculated according to:where A is a constant of 0.0028, HV is the hardness (N / mm2), P is theapplied load (N), and ΣL is the sum of crack lengths (mm) of imprints.

[0052] As used herein, the term “HV1 Vickers hardness” (i.e. applying a 1 kgf load)is a measure of the resistance of a sample to localized plastic deformation, which isobtained by indenting the sample with a Vickers tip at 1 kgf.

[0053] As used herein, the term “HV30 Vickers hardness” (i.e. applying a 30 kgfload) is a measure of the resistance of a sample to localized plastic deformation, whichis obtained by indenting the sample with a Vickers tip at 30 kgf.

[0054] As used herein, the ISO 28079-2009 standard specifies a method formeasuring the fracture toughness, and the hardness of hardmetals, cermets andcemented carbides at room temperature by an indentation method. The ISO 28079-2009standard applies to a measurement of the fracture toughness, and the hardnesscalculated by using the diagonal lengths of indentations, and cracks emanating from thecorners of a Vickers hardness indentation, and it is intended for use with metal-bondedcarbides and carbonitrides (e.g., hardmetals, cermets or cemented carbides). The testprocedures proposed in the ISO 28079-2009 standard are intended for use at ambient temperatures but can be extended to higher or lower temperatures by agreement. Thetest procedures proposed in the ISO 28079-2009 standard are also intended for use in anormal laboratory-air environment. They are typically not intended for use in corrosiveenvironments, such as strong acids or seawater. The ISO 28079-2009 standard is directly comparable to the standard ASTM B771 as disclosed for example in“Comprehensive Hard Materials book”, 2014, Elsevier Ltd. Page 312, which isincorporated herein by reference in its entirety. Thus, it can be assumed that themeasured fracture toughness and the hardness using the ISO 28079-2009 standard willbe the same as the measured values employing the ASTM B771 standard.

[0055] As used herein this disclosure, the term “corrosion” refers to a process thatconverts a metal into a chemically other form, such as for example an oxide, ahydroxide, a carbonate, or a sulfide. It is the gradual destruction, and disintegration ofmaterials (i.e., usually a metal) by chemical, or electrochemical reaction with theirenvironment. This means electrochemical oxidation of a metal in a reaction withan oxidant, such as, for example oxygen or sulfates. Rusting, which is namely theformation of iron oxides, is a well-known example of an electrochemical corrosionprocess. This type of damage typically produces oxide(s) or salt(s) of the original metal.Corrosion can also occur in materials other than metals, such as for instanceceramics or polymers etc.

[0056] As used herein this disclosure, the term “graphitization” refers to theformation of graphite. Graphite is a weak material property with a low ductility, thus displaying a low resistance to thermal stress increases, mechanical fatigue, or shock. Graphitization leads to an undesirable formation of localized weak areas on the affected cemented carbide body.

[0057] As used herein this disclosure, the term “ductility” is defined by the degree,whereby a given material can sustain plastic deformation under tensile stress, beforeultimately undergoing failure and breakage.

[0058] As used herein this disclosure, the term “green body” refers to a materialbeing in a form of a compacted powder, or compacted plates, before the material has physically been sintered.Self-neutron shielding high density cemented carbide compositions

[0059] The current disclosure stems from the premise of presenting self-neutronshielding high density cemented carbide compositions typically having a metallic binderweight from typically about 0.20 wt.% up to about 15 wt.% based on the total weight ofthe cemented carbide composition with a Cr amount in a range of from about 2 wt.% toabout 18 wt.% based on a total weight of the Fe-Cr based metallic binder phase. A self-neutron shielding high density cemented carbide composition for neutron shielding innuclear reactors is presented basically constituted of a ceramic hard phase, and an iron(Fe)-chromium (Cr) based metallic binder phase. The binder phase is uniquely composedof elements displaying an acceptably short radioactive half-life e.g., about 44 days for theFe, and about 27 days for the Cr. This is in stark contrast to cobalt (Co) and nickel (Ni),which have traditionally been used as metallic binders in cemented carbide compositions,and which unfavorably possess extremely long radioactive half-lives for elimination fromthe environment after having been irradiated during the fission and fusion reactions takingplace in the nuclear reactor. Moreover, when Cr is added into the cemented carbidecomposition, an improved corrosion resistance is established. Thus, the obtainedbeneficial effects are at least manifold. Environmentally safe self-neutron shieldingcemented carbide compositions are in effect produced for neutron shielding in nuclearreactors exhibiting an exceedingly high density with an improved corrosion resistance,and a short radioactive half-life activity for the components making up the cementedcarbide compositions. However, the examples disclosed herein are not strictly limited toonly neutron shielding in nuclear reactors. Essentially, they may further find a compelling utility and be implemented in connection with other systems, which may routinely require an efficacious neutron shielding and quelling capability. This may encompass forexample industrial security scanners emitting neutrons, industrial inspection systems,nuclear waste generated from for example defense, research and development (R&D) activities, utility, or medical uses, and handling of the generated nuclear waste, and othernuclear energy-related applications like decommissioning, and refueling stages of thenuclear reactor at the end of a duty cycle, which undesirably emit neutrons like e.g., nuclear waste recycling, neutron radiography (N-ray) devices employing neutron imagingtechniques, for elimination of neutrons scattered by construction elements, neutron generators used for example in oil well logging, and security inspection systems.

[0060] The ceramic hard phase of the self-neutron shielding high density cementedcarbide composition disclosed herein is most typically constituted of tungsten carbide(WC), sub-stoichiometric ditungsten carbide (W2C), or a combination thereof typically ina ratio of from about 4:1 to about 15:1. In certain particular examples, the ceramic hard phase may alternatively be composed of at least one of carbides of tungsten, titanium,tantalum, vanadium, chromium, or any combinations thereof. The ceramic hard phaseencompassing the aforementioned metal carbides may incorporate them in any combination that is not inconsistent and incompatible with the objectives of the present subject matter.

[0061] The ceramic hard phase of the self-neutron shielding high density cementedcarbide composition may typically be present in a weight from about 85.00 wt.% to about99.80 wt.% based on the total weight of the cemented carbide composition. In someexamples, the ceramic hard phase is present in a weight from about 87.00 wt.% to about99.80 wt.% based on the total weight of the cemented carbide composition. In otherexamples, the ceramic hard phase is present in a weight from about 89.00 wt.% to about99.80 wt.% based on the total weight of the cemented carbide composition. In yet otherexamples, the ceramic hard phase is present in a weight from about 91.00 wt.% to about99.80 wt.% based on the total weight of the cemented carbide composition. In still otherexamples, the ceramic hard phase is present in a weight from about 93.00 wt.% to about99.80 wt.% based on the total weight of the cemented carbide composition. In furtherexamples, the ceramic hard phase is present in a weight from about 95.00 wt.% to about99.80 wt.% based on the total weight of the cemented carbide composition. In furtherother examples, the ceramic hard phase is present in a weight from about 97.00 wt.% toabout 99.80 wt.% based on the total weight of the cemented carbide composition. Ineven other examples, the ceramic hard phase is present in a weight from about 99.00wt.% to about 99.80 wt.%, or from about 99.50 wt.% to about 99.80 wt.% based on thetotal weight of the cemented carbide composition.

[0062] The ceramic hard phase of the self-neutron shielding high density cementedcarbide composition may also be present in a weight from about 85.00 wt.% to about87.00 wt.%, from about 87.00 wt.% to about 89.00 wt.%, from about 89.00 wt.% to about91.00 wt.%, from about 85.00 wt.% to about 91.00 wt.%, from about 87.00 wt.% to about91.00 wt.%, from about 91.00 wt.% to about 93.00 wt.%, from about 93.00 wt.% to about95.00 wt.%, from about 95.00 wt.% to about 97.00 wt.%, from about 91.00 wt.% to about95.00 wt.%, from about 91.00 wt.% to about 97.00 wt.%, from about 93.00 wt.% to about97.00 wt.%, from about 97.00 wt.% to about 99.00 wt.%, from about 97.00 wt.% to about99.50 wt.%, or from about 97.00 wt.% to about 99.80 wt.%, based on the total weight ofthe cemented carbide composition.

[0063] The self-neutron shielding high density cemented carbide composition maygenerally include from about 0.20 wt.% to about 15.00 wt.% of the Fe-Cr based metallicbinder phase based on the total weight of the cemented carbide composition. In someexamples, the cemented carbide composition includes from about 0.25 wt.% to about15.00 wt.% of the Fe-Cr based metallic binder phase based on the total weight of thecemented carbide composition. In yet other examples, the cemented carbide compositionincludes from about 0.50 wt.% to about 15.00 wt.% of the Fe-Cr based metallic binderphase based on the total weight of the cemented carbide composition. In still otherexamples, the cemented carbide composition includes from about 0.75 wt.% to about15.00 wt.% of the Fe-Cr based metallic binder phase based on the total weight of thecemented carbide composition. In even other examples, the cemented carbidecomposition includes from about 1.00 wt.% to about 15.00 wt.% of the Fe-Cr basedmetallic binder phase based on the total weight of the cemented carbide composition. Inother examples, the cemented carbide composition includes from about 3.00 wt.% toabout 15.00 wt.% of the Fe-Cr based metallic binder phase based on the total weight ofthe cemented carbide composition. In still other examples, the cemented carbidecomposition includes from about 5.00 wt.% to about 15.00 wt.% of the Fe-Cr basedmetallic binder phase based on the total weight of the cemented carbide composition. Inyet other examples, the cemented carbide composition includes from about 7.00 wt.% toabout 15.00 wt.% of the Fe-Cr based metallic binder phase based on the total weight ofthe cemented carbide composition. In even other examples, the cemented carbidecomposition includes from about 9.00 wt.% to about 15.00 wt.% of the Fe-Cr basedmetallic binder phase based on the total weight of the cemented carbide composition. In further other examples, the cemented carbide composition includes from about 11.00wt.% to about 15.00 wt.% of the Fe-Cr based metallic binder phase based on the totalweight of the cemented carbide composition. In even further other examples, thecemented carbide composition includes from about 13.00 wt.% to about 15.00 wt.% ofthe Fe-Cr based metallic binder phase based on the total weight of the cemented carbide composition.

[0064] The Fe-Cr based metallic binder phase of the self-neutron shielding highdensity cemented carbide composition may also be present in a weight from about 0.20wt.% to about 0.25 wt.%, from about 0.20 wt.% to about 0.50 wt.%, from about 0.25 wt.%to about 0.50 wt.%, from about 0.50 wt.% to about 0.75 wt.%, from about 0.50 wt.% toabout 1.00 wt.%, from about 0.75 wt.% to about 1.00 wt.%, from about 0.50 wt.% to about3.00 wt.%, from about 0.75 wt.% to about 3.00 wt.%, from about 1.00 wt.% to about 3.00wt.%, from about 1.25 wt.% to about 3.00 wt.%, from about 1.50 wt.% to about 3.00 wt.%,from about 1.75 wt.% to about 3.00 wt.%, from about 2.00 wt.% to about 3.00 wt.%, from about 2.25 wt.% to about 3.00 wt.%, from about 2.50 wt.% to about 3.00 wt.%, from about2.75 wt.% to about 3.00 wt.%, from about 3.00 wt.% to about 5.00 wt.%, from about 5.00wt.% to about 7.00 wt.%, from about 7.00 wt.% to about 9.00 wt.%, from about 3.00 wt.%to about 9.00 wt.%, from about 5.00 wt.% to about 9.00 wt.%, from about 9.00 wt.% toabout 10.00 wt.%, from about 9.00 wt.% to about 11.00 wt.%, from about 9.00 wt.% toabout 13.00 wt.%, from about 10.00 wt.% to about 13.00 wt.%, from about 11.00 wt.% toabout 13.00 wt.%, or from about 12.00 wt.% to about 13.00 wt.%, based on the totalweight of the cemented carbide composition.

[0065] The self-neutron shielding high density cemented carbide composition maytypically include a Cr amount in the Fe-Cr based metallic binder phase in a range of fromabout 2 wt.% to about 18 wt.% based on the total weight of the Fe-Cr based metallicbinder phase. In some examples, the Cr amount is from a range of from about 4 wt.% toabout 18 wt.% based on the total weight of the Fe-Cr based metallic binder phase. Inother examples, the Cr amount is from a range of from about 6 wt.% to about 18 wt.%based on the total weight of the Fe-Cr based metallic binder phase. In still otherexamples, the Cr amount is from an a range of from about 8 wt.% to about 18 wt.% basedon the total weight of the Fe-Cr based metallic binder phase. In even other examples,the Cr amount is from a range of from about 10 wt.% to about 18 wt.% based on the totalweight of the Fe-Cr based metallic binder phase. In even further other examples, the Cramount is from a range of from about 12 wt.% to about 18 wt.% based on the total weightof the Fe-Cr based metallic binder phase. In still even further other examples, the Cramount is from a range of from about 14 wt.% to about 18 wt.%, or from about 16 wt.%to about 18 wt.% based on the total weight of the Fe-Cr based metallic binder phase.

[0066] The Cr amount in the Fe-Cr based metallic binder phase may also range offrom about 2 wt.% to about 4 wt.%, from about 4 wt.% to about 6 wt.%, from about 6 wt.% to about 8 wt.%, from about 2 wt.% to about 8 wt.%, from about 4 wt.% to about 8 wt.%, from about 8 wt.% to about 10 wt.%, from about 10 wt.% to about 12 wt.%, from about 12 wt.% to about 14 wt.%, from about 2 wt.% to about 12 wt.%, from about 2 wt.% to about 14 wt.%, from about 3 wt.% to about 14 wt.%, from about 4 wt.% to about 14 wt.%, fromabout 5 wt.% to about 14 wt.%, from about 6 wt.% to about 14 wt.%, from about 7 wt.%to about 14 wt.%, from about 8 wt.% to about 14 wt.%, from about 9 wt.% to about 14wt.%, from about 10 wt.% to about 14 wt.%, from about 11 wt.% to about 14 wt.%, fromabout 12 wt.% to about 14 wt.%, from about 13 wt.% to about 14 wt.%, from about 8 wt.% to about 15 wt.%, from about 9 wt.% to about 15 wt.%, from about 10 wt.% to about 15 wt.%, from about 11 wt.% to about 15 wt.%, from about 12 wt.% to about 15 wt.%, fromabout 13 wt.% to about 15 wt.%, from about 14 wt.% to about 15 wt.%, from about 3 wt.%to about 16 wt.%, from about 2 wt.% to about 16 wt.%, from about 4 wt.% to about 16 wt.%, from about 5 wt.% to about 16 wt.%, from about 6 wt.% to about 16 wt.%, from about 7 wt.% to about 16 wt.%, from about 8 wt.% to about 16 wt.%, from about 9 wt.% to about 16 wt.%, from about 10 wt.% to about 16 wt.%, from about 11 wt.% to about 16 wt.%, from about 12 wt.% to about 16 wt.%, from about 13 wt.% to about 16 wt.%, fromabout 14 wt.% to about 16 wt.%, from about 15 wt.% to about 16 wt.%, from about 8wt.% to about 17 wt.%, from about 9 wt.% to about 17 wt.%, from about 10 wt.% to about 17 wt.%, from about 11 wt.% to about 17 wt.%, from about 12 wt.% to about 17 wt.%, from about 13 wt.% to about 17 wt.%, from about 14 wt.% to about 17 wt.%, from about15 wt.% to about 17 wt.%, from about 16 wt.% to about 17 wt.%, from about 11 wt.% to about 18 wt.%, from about 13 wt.% to about 18 wt.%, from about 15 wt.% to about 18wt.%, or from about 17 wt.% to about 18 wt.%, based on the total weight of the Fe-Crbased metallic binder phase.

[0067] Grain growth inhibitors to suppress the WC and the sub-stoichiometric W2Cgrain growth during processing typically known to one of ordinary skilled in the art in thelikes of vanadium carbide (VC), chromium carbide (Cr3C2), tantalum carbide (TaC), andtitanium carbide (TiC), may be present in the self-neutron shielding high density cementedcarbide composition in any possible combination, and in any weight, that is notinconsistent and incompatible with the objectives of the present subject matter.

[0068] The grain growth inhibitors may be present in a weight from about 0.15 wt.%to about 2.00 wt.%, from about 0.25 wt.% to about 2.00 wt.%, from about 0.50 wt.% toabout 2.00 wt.%, from about 0.15 wt.% to about 0.50 wt.%, from about 0.75 wt.% to about2.00 wt.%, from about 1.00 wt.% to about 2.00 wt.%, from about 1.25 wt.% to about 2.00wt.%, from about 0.50 wt.% to about 1.25 wt.%, from about 0.50 wt.% to about 1.50 wt.%,from about 0.50 wt.% to about 1.75 wt.%, from about 0.75 wt.% to about 1.25 wt.%, fromabout 1.00 wt.% to about 1.25 wt.%, from about 1.00 wt.% to about 1.50 wt.%, from about1.25 wt.% to about 1.50 wt.%, from about 1.25 wt.% to about 1.75 wt.%, from about 1.25wt.% to about 2.00 wt.%, from about 1.50 wt.% to about 2.00 wt.%, or from about 1.75wt.% to about 2.00 wt.% based on the total weight of the cemented carbide composition.

[0069] The WC grain size, once sintered, may generally exhibit an average grainsize ranging for example from about 0.1 µm to about 30 µm. In some examples, the WCgrain size may range from about 1 µm to about 5 µm. In other examples, the WC grainsize may range from about 1 µm to about 10 µm. In still other examples, the WC grainsize may range from about 1 µm to about 15 µm. In yet other examples, the WC grainsize may range from about 1 µm to about 20 µm. In further examples, the WC grain sizemay range from about 1 µm to about 25 µm. In further other examples, the WC grain sizemay range from about 1 µm to about 30 µm.

[0070] The WC grain size may also range from about 5 µm to about 7 µm, fromabout 5 µm to about 10 µm, from about 10 µm to about 15 µm, from about 5 µm to about15 µm, from about 15 µm to about 20 µm, from about 5 µm to about 20 µm, from about20 µm to about 25 µm, from about 5 µm to about 25 µm, from about 25 µm to about 30µm, or from about 5 µm to about 30 µm.

[0071] The WC grain size defined by the cemented carbide may be determined bya linear-intercept technique using a line drawn across a calibrated scanning electron microscope (SEM) image of the cemented carbide. A length of the line may be measured by using a calibrated rule, where the line intercepts a grain of WC or W2C, and the linear- intercept technique is repeated for at least 100 WC or W2C grains to obtain an average grain size of the WC or the W2C. Alternatively, for determining a specific grain size, one having ordinary skill in the art may typically employ either dynamic digital image analysis (DIA), static laser light scattering (SLS) also known as laser diffraction, or by visual measurement by electron microscopy, a technique known as image analysis and light obscuration. Each method covers a characteristic size range within which measurement is possible. These ranges partly overlap. However, the results for measuring the same sample may vary all depending on the particular method that is used. A skilled artisan who wants to determine grain sizes or grain size distributions would readily know how each mentioned method is commonly performed and practiced. Thus, the reader is directed to for example, (i) “Comparison of Methods. Dynamic Digital Image Analysis, Laser Diffraction, Sieve Analysis”, Retsch Technology and (ii) the scientific publication by Kelly et al., “Graphical comparison of image analysis and laser diffraction particle size analysis data obtained from the measurements of spherical particle systems”, AAPSPharmSciTech. 2006 Aug 18; Vol.7(3):69, to further gain insight into each procedure andmethodology, all of which are incorporated herein by reference in their entirety.

[0072] Non-boronized cemented carbide compositions may typically exhibit anHV30 Vickers hardness in a range of from about 1345 HV30 to about 2450 HV30, and may generally demonstrate a Palmqvist fracture toughness (KIc) generally in a range offrom about 4.9 MPa√m to about 7.5 MPa√m.

[0073] In some examples, the HV30 Vickers hardness of the non-boronizedcemented carbide composition spans a range of from about 1400 HV30 to about 2450 HV30. In other examples, the HV30 Vickers hardness spans a range of from about 1500 HV30 to about 2450 HV30. In still other examples, the HV30 Vickers hardness spans a range of from about 1600 HV30 to about 2450 HV30. In yet other examples, the HV30 Vickers hardness spans a range of from about 1700 HV30 to about 2450 HV30. In yet even other examples, the HV30 Vickers hardness spans a range of from about 1800 HV30 to about 2450 HV30. In yet even further other examples, the HV30 Vickers hardness spans a range of from about 1900 HV30 to about 2450 HV30. In other examples, the HV30 Vickers hardness spans a range of from about 2000 HV30 to about 2450 HV30. In still other examples, the HV30 Vickers hardness spans a range of from about 2100 HV30 to about 2450 HV30. In yet other examples, the HV30 Vickers hardness spans a range of from about 2200 HV30 to about 2450 HV30. In even other examples, the HV30 Vickers hardness spans a range of from about 2300 HV30 to about 2450 HV30. In even further other examples, the HV30 Vickers hardness spans a range of from about 2400 HV30 to about 2450 HV30.

[0074] The HV30 Vickers hardness of the non-boronized cemented carbidecomposition may also span a range of from about 1345 HV30 to about 1400 HV30, fromabout 1400 HV30 to about 1500 HV30, from about 1500 HV30 to about 1600 HV30, fromabout 1345 HV30 to about 1500 HV30, from about 1345 HV30 to about 1600 HV30, fromabout 1345 HV30 to about 1700 HV30, from about 1345 HV30 to about 1800 HV30, from about 1345 HV30 to about 1900 HV30, from about 1345 HV30 to about 2000 HV30, from about 1345 HV30 to about 2100 HV30, from about 1345 HV30 to about 2200 HV30, fromabout 1345 HV30 to about 2300 HV30, from about 1345 HV30 to about 2400 HV30, fromabout 1600 HV30 to about 1700 HV30, from about 1700 HV30 to about 1800 HV30, fromabout 1800 HV30 to about 1900 HV30, from about 1700 HV30 to about 1900 HV30, fromabout 1700 HV30 to about 2000 HV30, from about 1700 HV30 to about 2100 HV30, from about 1700 HV30 to about 2200 HV30, from about 1700 HV30 to about 2300 HV30, fromabout 1700 HV30 to about 2400 HV30, from about 1800 HV30 to about 2000 HV30, fromabout 1800 HV30 to about 2100 HV30, from about 1800 HV30 to about 2200 HV30, from about 1800 HV30 to about 2300 HV30, from about 1800 HV30 to about 2400 HV30, fromabout 2000 HV30 to about 2100 HV30, from about 2100 HV30 to about 2200 HV30, from about 1900 HV30 to about 2000 HV30, from about 1900 HV30 to about 2100 HV30, fromabout 1900 HV30 to about 2200 HV30, from about 1900 HV30 to about 2300 HV30, fromabout 1900 HV30 to about 2400 HV30, from about 2000 HV30 to about 2200 HV30, fromabout 2200 HV30 to about 2300 HV30, from about 2300 HV30 to about 2400 HV30, or from about 2200 HV30 to about 2400 HV30.

[0075] Non-boronized cemented carbide compositions may further demonstrate anHV1 Vickers hardness in a range of from about 1430 HV1 to about 2045 HV1.

[0076] In some examples, the HV1 Vickers hardness of the non-boronizedcemented carbide composition spans a range of from about 1500 HV1 to about 2045 HV1. In other examples, the HV1 Vickers hardness spans a range of from about 1550 HV1 to about 2045 HV1. In still other examples, the HV1 Vickers hardness spans a range of from about 1600 HV1 to about 2045 HV1. In yet other examples, the HV1 Vickers hardness spans a range of from about 1650 HV30 to about 2045 HV1. In yet even other examples, the HV1 Vickers hardness spans a range of from about 1700 HV1 to about 2045 HV1. In yet even further other examples, the HV1 Vickers hardness spans a range of from about 1750 HV1 to about 2045 HV1. In other examples, the HV1 Vickers hardness spans a range of from about 1800 HV30 to about 2045 HV1. In still other examples, the HV1 Vickers hardness spans a range of from about 1850 HV30 to about 2045 HV1. In yet other examples, the HV1 Vickers hardness spans a range of from about 1900 HV1 to about 2045 HV1. In even other examples, the HV1 Vickers hardness spans a range of from about 1950 HV30 to about 2045 HV1. In even further other examples,the HV1 Vickers hardness spans a range of from about 2000 HV1 to about 2045 HV1.

[0077] The HV1 Vickers hardness of the non-boronized cemented carbidecomposition may also span a range of from about 1500 HV1 to about 1550 HV1, from about 1550 HV1 to about 1600 HV1, from about 1600 HV1 to about 1650 HV1, from about 1500 HV1 to about 1600 HV1, from about 1500 HV1 to about 1650 HV1, from about 1550 HV1 to about 1650 HV1, from about 1650 HV1 to about 1700 HV1, from about 1700 HV1 to about 1750 HV1, from about 1750 HV1 to about 1800 HV1, from about 1500 HV1 toabout 1800 HV1, from about 1550 HV1 to about 1800 HV1, from about 1600 HV1 to about 1800 HV1, from about 1650 HV1 to about 1800 HV1, from about 1700 HV1 to about 1800HV1, from about 1750 HV1 to about 1800 HV1, from about 1800 HV1 to about 1850 HV1,from about 1850 HV1 to about 1900 HV1, from about 1900 HV1 to about 1950 HV1, fromabout 1950 HV1 to about 2000 HV1, from about 1500 HV1 to about 1850 HV1, from about 1550 HV1 to about 1850 HV1, from about 1600 HV1 to about 1850 HV1, from about 1650HV1 to about 1850 HV1, from about 1700 HV1 to about 1850 HV1, from about 1750 HV1to about 1850 HV1, from about 1500 HV1 to about 1950 HV1, from about 1550 HV1 toabout 1950 HV1, from about 1600 HV1 to about 1950 HV1, from about 1650 HV1 to about1950 HV1, from about 1700 HV1 to about 1950 HV1, from about 1750 HV1 to about 1950HV1, from about 1800 HV1 to about 1950 HV1, from about 1850 HV1 to about 1950 HV1,from about 1500 HV1 to about 2000 HV1, from about 1550 HV1 to about 2000 HV1, fromabout 1600 HV1 to about 2000 HV1, from about 1650 HV1 to about 2000 HV1, from about1700 HV1 to about 2000 HV1, from about 1750 HV1 to about 2000 HV1, from about 1800 HV1 to about 2000 HV1, from about 1850 HV1 to about 2000 HV1, or from about 1900 HV1 to about 2000 HV1.

[0078] In some examples, the Palmqvist fracture toughness (KIc) of the non-boronized cemented carbide composition spans a range of from about 5.2 MPa√m toabout 7.5 MPa√m. In other examples, the Palmqvist fracture toughness (KIc) spans arange of from about 5.5 MPa√m to about 7.5 MPa√m. In still other examples, thePalmqvist fracture toughness (KIc) spans a range of from about 5.8 MPa√m to about 7.5 MPa√m. In yet other examples, the Palmqvist fracture toughness (KIc) spans a range offrom about 6.1 MPa√m to about 7.5 MPa√m. In even other examples, the Palmqvistfracture toughness (KIc) spans a range of from about 6.4 MPa√m to about 7.5 MPa√m.In even further other examples, the Palmqvist fracture toughness (KIc) spans a range of from about 6.7 MPa√m to about 7.5 MPa√m. In even additional other examples, the Palmqvist fracture toughness (KIc) spans a range of from about 7.0 MPa√m to about 7.5 MPa√m. In other examples, the Palmqvist fracture toughness (KIc) spans a range of from about 7.2 MPa√m to about 7.5 MPa√m.

[0079] The Palmqvist fracture toughness (KIc) of the non-boronized cementedcarbide composition may also encompass a range of from about 4.9 MPa√m to about 5.2MPa√m, from about 5.2 MPa√m to about 5.5 MPa√m, from about 5.5 MPa√m to about 5.8 MPa√m, from about 4.9 MPa√m to about 5.5 MPa√m, from about 4.9 MPa√m to about5.8 MPa√m, from about 4.9 MPa√m to about 6.1 MPa√m, from about 4.9 MPa√m to about6.4 MPa√m, from about 5.2 MPa√m to about 5.8 MPa√m, from about 5.2 MPa√m to about6.1 MPa√m, from about 5.2 MPa√m to about 6.4 MPa√m, from about 5.8 MPa√m to about6.1 MPa√m, from about 5.2 MPa√m to about 6.1, from about 5.2 MPa√m to about 6.4,from about 5.5 MPa√m to about 6.4, from about 6.1 MPa√m to about 6.4 MPa√m, fromabout 5.8 MPa√m to about 6.4 MPa√m, from about 6.4 MPa√m to about 6.7 MPa√m, from about 6.7 MPa√m to about 7.0 MPa√m, from about 7.0 MPa√m to about 7.2 MPa√m, from about 7.2 MPa√m to about 7.5 MPa√m, from about 6.7 MPa√m to about 7.2 MPa√m, from about 5.0 MPa√m to about 7.5 MPa√m, from about 5.1 MPa√m to about 7.5 MPa√m, from about 5.3 MPa√m to about 7.5 MPa√m, from about 5.4 MPa√m to about 7.5 MPa√m, from about 5.6 MPa√m to about 7.5 MPa√m, from about 5.7 MPa√m to about 7.5 MPa√m, from about 5.9 MPa√m to about 7.5 MPa√m, from about 6.0 MPa√m to about 7.5 MPa√m, from about 6.2 MPa√m to about 7.5 MPa√m, from about 6.3 MPa√m to about 7.5 MPa√m, from about 6.5 MPa√m to about 7.5 MPa√m, from about 6.6 MPa√m to about 7.5 MPa√m, from about 6.8 MPa√m to about 7.5 MPa√m, from about 6.9 MPa√m to about 7.5 MPa√m, from about 7.1 MPa√m to about 7.5 MPa√m, from about 7.3 MPa√m to about 7.5 MPa√m, or from about 7.4 MPa√m to about 7.5 MPa√m.Methods of preparing self-neutron shielding sintered high density cementedcarbides

[0080] A specifically targeted grain size of the cemented carbide can be obtainedby subjecting the ceramic hard phase powder, and the Fe-Cr based metallic binder phasepowder to a wet milling operation for several hours (e.g., 8, 16, 32, 64 hours) underambient conditions (i.e., 25º C, 298.15 K and a pressure of 101.325 kPa in a ball mill, anattritor mill, or a planetary mill) to form a powder blend. In some examples, instead of using a ball, an attritor mill, or a planetary mill as the physical blending apparatus, any other way of mixing known to a skilled artisan in powder processing, such as e.g.ultrasonic mixing may instead be the choice of the blending method. Thus, in this case, ultrasonic mixing uses ultrasonic sound energy and frequencies to effectively process for example powders, pastes, liquids, and combinations thereof with a breakthrough speed,quality and repeatability. Powders of nearly any size, material characteristic, ormorphology are rapidly and thoroughly mixed by using for example an acoustic mixer. Acoustic processing is frequently orders of magnitude faster than traditional technologies. Here, the acoustic mixer may for example employ a 60Hz frequency motion, which then causes each particle to randomly collide with adjacent particles, diverting their paths, colliding and then re-colliding with other particles behaving in equally chaotic fashion.The main purpose of the blending operation is to facilitate a good and an even Fe-Crbased metallic binder phase powder distribution, and an advantageous wettabilitybetween the powder constituents. The core reason for subjecting the powders to the wetmilling / blending operation is to strengthen the physical integrity of the blended ceramichard phase powder, and the Fe-Cr based metallic binder phase powder, and todeagglomerate the tungsten carbide (WC), the ditungsten carbide (W2C), and the FeCrpowders. An acceptable Fe-Cr based metallic binder phase powder distribution, and agood quality of the wettability between the powder components are key parameters forobtaining self-neutron shielding cemented carbides of stellar physical quality. On theother hand, if the Fe-Cr based metallic binder phase powder distribution, and wettabilityare of a bad quality, the downside is that pores and cracks may undesirably emerge as aresult of this in the final sintered body, which is damaging to the quality of the obtainedself-neutron shielding cemented carbide. In some instances, the ceramic hard phase powder and the Fe-Cr based metallic binder powder can be crushed, or otherwisecomminuted prior to the blending operation.

[0081] As would be apparent to a skilled artisan, in the case for wet milling, this isdone by first adding a milling liquid to the powder to form a milling powder slurrycomposition. The milling liquid may be water, an alcohol, such as but not limited toethanol, methanol, isopropanol, butanol, cyclohexanol, another organic solvent in thelikes of for example acetone or toluene, an alcohol mixture, an alcohol and another solvent mixture, or like constituents. The properties of the milling powder slurry composition are dependent on, among other things, the amount of the milling liquid thatis added. Because the drying of the milling powder slurry composition requires substantial amount of energy, the amount of the used milling liquid should be minimized to keep costs down. However, enough milling liquid needs to be added to achieve aneasily pumpable milling powder slurry composition and avoid clogging of the system.Moreover, other compounds commonly known in the art to a skilled artisan can be addedto the slurry e.g., dispersion agents, pH-adjusters, lubricants, and anti-flocculating agents.Non-limiting example of organic binder(s), such as e.g., polyethylene glycol (PEG),paraffin, polyvinyl alcohol (PVA), long chain fatty acids, wax, or any combinations thereof,or like components may be added to the milling powder slurry composition prior to themilling typically from for example 15 vol. % and 25 vol. % (i.e., total volume % made upby each mentioned component), from about 17 vol. % to about 25 vol. %, from about 20 vol. % to about 25 vol. %, from about 22 vol. % to about 25 vol. %, from about 24 vol. %to about 25 vol. % based on the total volume of the formed slurry. This is done to facilitatethe formation of a proper ceramic hard phase powder, and a Fe-Cr binder phase powderblend during the milling operation, and additionally to act as a pressing agent, and lasty to allow easy handling of the green body in the following pressing / forming steps described hereinafter.

[0082] The milled powder slurry composition can next be spray-dried, air-dried,freeze-dried, or vacuum-dried, and granulated to form free-flowing ready-to-press (RTP)cemented carbide powder aggregates, or agglomerates most typically displaying asubstantial spherical shape, or a substantial spherical-like shape. As used herein this disclosure, the term “free-flowing” refers to loosely packed cemented carbide powders exhibiting a pore space between each free-flowing particle of the self-neutron shielding high density cemented carbide powder with no physical restrictions, or barriers created, suppressing the free-flowing capacity of the particles of the cemented carbide powder.

[0083] In the case of for example spray-drying shown in FIG. 1, the milling powderslurry composition constituted of the ceramic hard phase powder 5 and the Fe-Cr basedmetallic binder phase powder 5 mixed with the organic liquid, and the organic binder(s)may be atomized through an appropriate nozzle 1 in a drying tower by forming a spray,where small discrete droplets 4 are instantaneously dried after forming liquid bridges 4A,by a horizontal inflow of a stream of hot gas into the drying tower, for instance in a streamof nitrogen, argon, or air to form substantially spherical, or spherical-like powderagglomerates 5A with free-flowing properties. As used herein, “atomization” refers to aprocess, where a bulk liquid feed is suitably converted into discrete droplets 4 by forminga spray, thus significantly increasing the surface area of the bulk feed liquid, and therebyincreasing considerably the achievable rates of evaporation of a given solvent (i.e., millingliquid). The atomization stage is designed to create optimum conditions for evaporationof the given solvent from the milling powder slurry composition. Nozzles 1, and rotaryatomizers 1 are used to form sprays. Drying towers may be equipped with just one suchnozzle 1, and rotary atomizer 1, or alternatively with a plurality of such nozzles 1, androtary atomizers 1 to obtain granulated spherical, or substantially spherical-like ceramichard phase powder, and Fe-Cr based metallic binder phase powder blend agglomerates5A with free-flowing properties.

[0084] The granules of the ready-to-press (RTP) ceramic hard phase powder, andFe-Cr based metallic binder phase powder agglomerates 5A with the free-flowingproperties are next pressed / formed, or otherwise consolidated into a green article or green body in the preparation for the sintering procedure described hereinafter. A greenbody is formed of the ready-to-press (RTP) powder by using conventionalpressing / forming techniques in the powder metallurgy art, such as the following, but without limitation cold tool pressing technology including multi axial pressing (MAP), extruding or metal injection molding (MIM), cold isostatic pressing (CIP, i.e., pressure isapplied in 3 directions or axis), pill pressing, tape casting, additive manufacturing (AM) oradditive layer manufacturing (ALM), and other methods generally known to a skilled artisan in the powder metallurgy art. Any pressing / forming consolidation method can be utilized that is not inconsistent and incompatible with the objectives of the present subject matter. Importantly, pressing / forming yields a green density, and / or strength that permitseasy handling, and green machining due to the processed material essentially being inthe form of a compacted powder. In one example of the present disclosure, the forming is done by a pressing operation. Here, the pressing may be conducted by a uniaxial pressing consolidation operation at a force commonly used from 5 ton to 300 ton.Additionally, machining in the green state may be required to achieve a desired green body shape.

[0085] Boron is an effective absorber of low energy neutrons, otherwisepenetrating a tungsten-based shield. The presence of boron thus improves the shieldingproperty of the material during operation. Further, additional advantages of employingboron are at least manifold. First, boron is self-shielding for the safe handling, anddisposal of the parts at the end of the nuclear reactor’s life. Second, the presence ofboron will also help enhance the sintering capability of the material achieved byessentially reducing the melting point of the metallic binder. Third, the boron treatmentoperation provides the freedom of choice of introducing the boron directly into thesintering tray, or the sintering mould used as a pressing and sintering media, or the boroncan be applied onto the outer surface of the green body itself, such that a boronconcentration gradient is formed during the sintering process. This favorably allows boththe formation of a boron concentration gradient during the sintering process on the outersurface of the green body itself, or (i) alternatively, or (ii) in addition on an outer surfaceof sintered cemented carbide parts in yet other examples. Thus, in some examples, theouter surface of the green body is coated with a boron-containing agent, such that a boronconcentration gradient is formed during the sintering operation. In other examples, theboron-containing agent is added directly into the sintering tray, or the sintering mould. Inyet other examples, the boron-containing agent may further optionally be coated onto theouter surface of the sintered cemented carbide parts, such that a boron concentrationgradient is formed on the outer surface of the sintered cemented carbide parts afterconducting an additional heat treatment at a temperature range of typically from about1200°C to about 1800°C. In still other examples, the boron-containing agent may beadded (I) onto the outer surface of the green body, in addition to being added (II) onto theouter surface of sintered cemented carbide parts. This is done to form a boronconcentration gradient on the outer surface of the green body during the sinteringprocess, as well as on the outer surface of the sintered cemented carbide parts afterperforming an additional heat treatment at a temperature of typically from about 1200°Cto about 1800°C. In certain particular examples boron, or boron nitride (BN) can be mixedwith an organic binder like e.g. PEG, and an alcohol water mixture like e.g., ethanol andwater, to ensure a good coating on the outer surface of the green body. Essentially, itshould be emphasized that the boron-containing agent is typically coated onto the outersurface of the green body, or onto the outer surface of the sintered cemented carbideparts, or both. Here, the main advantage of treating with the boron-containing agent onthe outer surface of the green body, or the outer surface of the sintered cemented carbideparts, or both is to prevent the presence of any unreacted boron-containing agent insidethe final sintered part. In such a given scenario, if any unreacted boron-containing agentwere indeed present inside the boron-treated green body, or inside the boron-treatedsintered cemented carbide parts, it would undesirably decrease the density of thematerial. Moreover, it would result in a detrimental effect on the overall materialmechanical property, as well as impart a suppressing effect on its neutron quelling and blocking ability.

[0086] Now turning the attention of the reader to FIG.2A and FIG.2B, these figuresrespectively display different structural phases of the self-neutron shielding cementedcarbide either (i) before, or (ii) after the outer surface of the green body 2 has beensubjected to boron coating 3, in accordance with the present subject matter. FIG.2A andFIG. 2B show the green body 2 of the self-neutron shielding cemented carbide, whichgreen body, resulting from a ready-to-press (RTP) powder that has been pressed, andhas an outer surface 6. FIG. 2B demonstrates the formation of a boron concentrationgradient 12 after coating the boron 3 on the outer surface 6 of the green body 2, and thefollowing penetration of the formed boron concentration gradient 12 on the outer surface6 of the green body 2 of the self-neutron shielding cemented carbide during the sinteringprocess. FIG. 2B shows that the concentration of the boron 3 layer gradually gets lowerfrom the outer surface 6 towards the inside of the green body 2 through diffusion facilitatedduring the sintering process, thus favorably providing the entirety of the positive benefitsdescribed before in the sintered body. Optionally, any unreacted boron 3 may beremoved after the sintering process is fully complete, as would be readily apparent to onehaving ordinary skill in the art. As used herein this disclosure, the term, “a boronconcentration gradient” is meant to characterize “a gradient of boron containing phases”,or “a gradient of a boron containing phase” by undergoing a diffusion during the sinteringprocess as shown in FIG. 2B.

[0087] The boron coated green body may next be subjected to a pre-sinteringtemperature elevation procedure in a sintering furnace, to completely remove the organicbinder(s), which is also called depegging or dewaxing of the organic binder(s). Suitabletemperatures for the complete removal of the organic binder(s) may be employed startingfrom 150°C and ending at 450°C, starting from 150°C and ending at 500°C, starting from150°C and ending at 550°C, starting from 150°C and ending at 600°C, starting from 250°Cand ending at 450°C, starting from 250°C and ending at 500°C, starting from 250°C andending at 550°C, starting from 250°C and ending at 600°C, starting from 300°C andending at 450°C, starting from 300°C and ending at 500°C, starting from 300°C andending at 550°C, or starting from 300°C and ending at 600°C. This may typically beperformed in a reactive H2atmosphere with a hydrogen (H2) flow rate applied at about 1000 liters / hour to about 10000 liters / hour, applied at about 3000 liters / hour to about 10000 liters / hour, applied at about 6000 liters / hour to about 10000 liters / hour, or appliedat about 9000 liters / hour to about 10000 liters / hour. The temperature may typically beincreased constantly at a rate of for example about 0.70°C / min. In some examples, afterthe complete organic binder(s) removal, the temperature may be increased in tandemsequentially at a rate of about 2°C / min. shifted to about 10°C / min., when a certaintemperature in an operated temperature range has been reached after the completeremoval of the organic binder(s), or for example at a rate of about 2°C / min. changed toabout 5°C / min., or changed to about 7°C / min., again when a particular temperature in anoperated temperature range has been reached. The aforementioned temperature rangesfor the depegging or dewaxing (i.e., debinding of the organic binder) may generally bereached after heating for about 60 minutes to about 90 minutes, or for about 60 minutes to about 7 hours in the sintering furnace. Thus, in general, the particular type of heating- pattern chosen is determined and performed, and for the particular amount of time, in amanner, that confers and thereby provides a desired complete dewaxed phase-transformation of the cemented carbide powder. In general, the pre-sintering cycle forcomplete dewaxing of the organic binder(s) may be conducted in a reactive (H2)atmosphere, in vacuum, or in a non-reactive inert atmosphere e.g., nitrogen (N2) or argon(Ar).

[0088] The cemented carbide powder thereafter undergoes a consolidationprocess to ultimately form the high density cemented carbide for neutron shielding. As used herein this disclosure, the term “consolidation process” is meant to either include(A) any process that in combination (i) compacts (i.e., presses), and (ii) consolidates (i.e.,densifies, thus sinters the material by a high temperature heating operation) the cementedcarbide powder simultaneously, or (B) densifies only by a high temperature heatingoperation as applied solely during vacuum sintering, which does not have anycompaction / pressure happening during the vacuum sintering / consolidation operation.

[0089] In some examples, the consolidation process may be done by hot pressing(HP) the cemented carbide powder. HP is a relatively slow process, and compacting isusually uniaxial. Heating is done at the same time by elements that are integrated in thepress.

[0090] In other examples, the consolidation process may be performed by hotisostatic pressing (HIP). HIP is similarly a relatively slow process, as well, andcompacting is isostatic, i.e., pressure is applied in 3 directions or axis. Heating isperformed at the same time by elements that are integrated in the press. Thus, HIPsubjects the cemented carbide powder to simultaneously both an elevated temperature,and a pressurizing isostatic gas pressure in, for example, a high pressure containmentvessel. The pressurizing gas that is used may, for example, be argon. An inert gas suchas argon is most typically used, so that the material undergoing HIP, does not chemicallyreact. The chamber is heated, causing the pressure inside the vessel to increase. Thepressure is applied to the cemented carbide powder from all 3 directions or axis. Theinert argon gas may be applied typically from about 7,350 psi (about 50.7 MPa) to about45,000 psi (about 310 MPa), with about 14,500 psi (about 100 MPa) typically being themost used pressure, or alternatively from about 800 bar (80 MPa) to about 1200 bar (120MPa).

[0091] In yet other examples, the consolidation process may be performed byspark plasma sintering (SPS). The main nature and characteristics of SPS is that apulsed direct current (DC), or an alternating current (AC) current passes through asintering mould. The heat generation is internal, in direct contrast to HP and HIP, wherethe heat is provided by external heating elements. This facilitates extremely high heatingand cooling rates (e.g., up to 1000 K / min). Thus, the sintering process is generally fast,and typically completed within a few minutes. The speed of the process ensures that it has the potential of densifying cemented carbide powders with nanosize or nanostructure, while avoiding coarsening, which accompanies standard densification techniques.Compacting is typically uniaxial in SPS, although in terms of stress state, one canpotentially reach an isostatic stress state, because of the effect imparted by the rigidsintering mould that contains and encases the cemented carbide powder. As mentionedabove, heating is supplied by subjecting the sintering mould to an electrical current fieldthat passes through the sintering mould containing the cemented carbide powder. SPSmay be used as a tool for forming functionally graded soft-magnetic cemented carbide powders, and it is useful in accelerating the development of magnetic materials. In stillother examples, similar methodologies of such described technologies before mayequally well be adopted for the consolidation process of the cemented carbide powder,which would be apparent to one having ordinary skill in the art.

[0092] The applied temperature for the previously mentioned sinteringconsolidation processes in the sintering furnace may principally be in a range startingfrom 1200°C and ending at 1500°C, starting from 1200°C and ending at 1600°C, startingfrom 1200°C and ending at 1700°C, starting from 1200°C and ending at 1800°C, startingfrom 1400°C and ending at 1500°C, starting from 1400°C and ending at 1600°C, startingfrom 1400°C and ending at 1700°C, starting from 1400°C and ending at 1800°C, startingfrom 1500°C and ending at 1600°C, starting from 1500°C and ending at 1700°C, orstarting from 1500°C and ending at 1800°C. A dwell time may be introduced at themaximum temperature in an applied temperature range and a specific pressure range, which may typically be from 1 minute to 60 minutes, from 20 minutes to 60 minutes, from25 minutes to 60 minutes, from 30 minutes to 60 minutes, from 35 minutes to 60 minutes,from 40 minutes to 60 minutes, from 45 minutes to 60 minutes, from 50 minutes to 60 minutes, or from 55 minutes to 60 minutes. The particular sintering temperature range ischosen, in a manner, that will result in a sufficient melting of the Fe-Cr based metallicbinder phase. During this process, the Fe-Cr based metallic binder phase will eventuallyenter the liquid stage, while the carbide grains having a considerably higher melting pointwill remain in a solid stage. As a result of this process, the Fe-Cr based metallic binderis anchoring and cementing the carbide grains, thus forming the self-neutron shieldingFe-Cr based metallic binder matrix composite with its distinct material properties.

[0093] In the case for HIP, HIP can be performed on the cemented carbide powder,or alternatively, as an extra post consolidation step sequentially performed on an alreadysintered cemented carbide. Thus, the sintered cemented carbide may undergo anadditional sequential HIP-treatment step from typically 30 minutes to 60 minutes, thereby yielding a high-pressure HIP-process. This additional sequential HIP-step fulfils the significant purpose of eliminating the presence of any potential porosity that may bepresent in the sintered cemented carbide. During the HIP-process, the appliedtemperature may, for example, range starting from 1300°C and ending at 1500°C, starting from 1300°C and ending at 1600°C, starting from 1300°C and ending at 1700°C, startingfrom 1300°C and ending at 1800°C, starting from 1300°C and ending at 1900°C, startingfrom 1300°C and ending at 2000°C, starting from 1400°C and ending at 1500°C, starting from 1400°C and ending at 1600°C, starting from 1400°C and ending at 1700°C, starting from 1400°C and ending at 1800°C, starting from 1400°C and ending at 1900°C, starting from 1400°C and ending at 2000°C, starting from 1500°C and ending at 1600°C, starting from 1500°C and ending at 1700°C, starting from 1500°C and ending at 1800°C, starting from 1500°C and ending at 1900°C, or starting from 1500°C and ending at 2000°C, withan applied pressure typically ranging from about 7,350 psi (about 50.7 MPa) to about45,000 psi (about 310 MPa), with about 14,500 psi (about 100 MPa) generally being themost typical applied pressure, or alternatively from about 800 bar (80 MPa) to about 900 bar (90 MPa), from about 800 bar (80 MPa) to about 1000 bar (100 MPa), from about 800 bar (80 MPa) to about 1100 bar (110 MPa), 800 bar (80 MPa) to about 1200 bar (120MPa), from about 900 bar (90 MPa) to about 1000 bar (100 MPa), from about 900 bar (90MPa) to about 1100 bar (110 MPa), from about 900 bar (90 MPa) to about 1200 bar (120 MPa), from about 1000 bar (100 MPa) to about 1100 bar (110 MPa), from about 1000 bar (100 MPa) to about 1200 bar (120 MPa), or from about 1100 bar (110 MPa) to about 1200 bar (120 MPa).

[0094] Alternatively, the consolidation process may be performed by asimultaneous non-sequential (i.e. thus as opposed to above, where the sintered cemented carbide sequentially undergoes a further HIP-treatment) high pressure sinter- hipping process in a sinter-HIP furnace at a temperature range starting from 1200°C and ending at 1500°C, starting from 1200°C and ending at 1600°C, starting from 1200°C and ending at 1700°C, starting from 1200°C and ending at 1800°C, starting from 1400°C and ending at 1500°C, starting from 1400°C and ending at 1600°C, starting from 1400°C and ending at 1700°C, starting from 1400°C and ending at 1800°C, starting from 1500°C and ending at 1600°C, starting from 1500°C and ending at 1700°C, or starting from 1500°Cand ending at 1800°C, with an applied pressure typically ranging from about 7,350 psi(about 50.7 MPa) to about 45,000 psi (about 310 MPa), with about 14,500 psi (about100 MPa) generally being the most typical applied pressure, or alternatively from about800 bar (80 MPa) to about 900 bar (90 MPa), from about 800 bar (80 MPa) to about 1000 bar (100 MPa), from about 800 bar (80 MPa) to about 1100 bar (110 MPa), 800 bar (80 MPa) to about 1200 bar (120 MPa), from about 900 bar (90 MPa) to about 1000 bar (100 MPa), from about 900 bar (90 MPa) to about 1100 bar (110 MPa), from about 900 bar (90 MPa) to about 1200 bar (120 MPa), from about 1000 bar (100 MPa) to about 1100 bar (110 MPa), from about 1000 bar (100 MPa) to about 1200 bar (120 MPa), or from about 1100 bar (110 MPa) to about 1200 bar (120 MPa).

[0095] Alternatively, to the methodologies described above, the cemented carbidepowder may also be disposed in for example refractory metal containers. The refractory metal containers containing the cemented carbide powder may be sealed, and then placed in a high-pressure high temperature (HPHT) cell, and HPHT sintering conditions can then be applied to form the neutron shielding high density cemented carbide. The refractory metal containers can be made of any suitable material, including any suitable refractory metal selected from the group consisting of tantalum, niobium, and molybdenum. However, different variations may exist, as to the particular material compartment-type that the cemented carbide powder may be loaded into. Alternatively, in other examples, the cemented carbide powder may be loaded into a refractory capsule constructed of hard metals, together with, or without a cemented WC support structure instead of being loaded into metal containers. Several of such refractory capsules maybe compiled into a high-pressure cell-core. Still in other examples, the cemented carbide powder may be loaded into a shallow, flat-bottomed cup made of a suitable material, such as for example cemented WC. The cup may be covered with a refractory metal disc, and thereafter used in the HPHT sintering consolidation operation. In yet other examples, the cup may me made of a refractory metal, and instead, a cemented WC disc may form the covering lid. HPHT sintering, performed in typically a cubic press or a belt press, may include subjecting the sample to internal cell pressures spanning from about 4 gigapascal (GPa) to about 8 GPa, from about 5 GPa to about 8 GPa, from about 6 GPa to about 8 GPa, from about 7 GPa to about 8 GPa, 4 GPa to about 7 GPa, from about 5 GPa to about 7 GPa, from about 6 GPa to about 7 GPa, from about 4 GPa to about 6 GPa, or from about 5 GPa to about 6 GPa, with a hydraulic pressure generally ranging from about 55 MPa to about 85 MPa. Used internal cell temperatures during the conducted HPHT sintering operation may ideally range from about 1500°C to about 1600°C, from about 1500°C to about 1700°C, from about 1500°C to about 1800°C, from about 1500°C to about 1900°C, from about 1500°C to about at 2000°C, from about 1600°C to about 2000°C, from about 1700°C to about 2000°C, from about 1800°C to about 2000°C, from about 1900°C to about 2000°C, from about 1700°C to about 1900°C, or from about 1800°C to about 1900°C. A dwell time may be introduced at the maximum temperature in an adopted temperature range and a specific pressure range, which may typically be from 1 minute to 60 minutes, 20 minutes to 60 minutes, from 25 minutes to 60 minutes, from 30 minutes to 60 minutes, from 35 minutes to 60 minutes, from 40 minutes to 60 minutes, from 45 minutes to 60 minutes, from 50 minutes to 60 minutes, or from 55 minutes to 60 minutes. The temperature may typically be elevated constantly at a rate of for example about 0.70°C / min. In some examples, the temperature may also beincreased in tandem sequentially at a rate of about 2°C / min. switched to about 10°C / min.,or for instance at a rate of about 2°C / min. then changed to about 7°C / min, or for example at a rate of about 2°C / min. switched to about 5°C / min., when a certain particular temperature has been reached in an applied temperature range. After having performed the dwell time employed at the maximum temperature in an applied temperature range, a cooling step is typically performed via conducting a step-wise temperature drop characterized by a drop rate of for example about 50°C / min. for typically about 5 minutes,or a drop rate of about 50°C / min. for about 10 minutes, or a drop rate of about 100°C / min. for about 5 minutes, or a drop rate of about 100°C / min. for about 10 minutes. Next, all heating energy may be terminated and dissipated via a secondary rapid temperature drop by way of ideally using coolants to eventually a temperature of about 25°C under ambient conditions.

[0096] Turning now to FIG. 3A, this figure depicts a flow diagram demonstratingthe individual process steps of making a self-neutron shielding high density cementedcarbide for neutron shielding in accordance with the present subject matter. FIG. 3Ashows that in step 100, the process is initiated by blending a powder mixture in a millingliquid including powders forming hard constituents of a ceramic hard phase and an iron (Fe)-chromium (Cr) based metallic binder phase present in an amount of from about 0.20wt.% to about 15 wt.% having a Cr amount in a range of from about 2 wt.% to about 18wt.% based on a total weight of the Fe-Cr based metallic binder phase, with an organicbinder to form a slurry blend. Thereafter, the formed slurry blend is next dried in step 102by vacuum drying, air drying, freeze drying, or spray drying through atomization, followedby undergoing compaction to form a green body 2 in step 104. The green body 2 isthereafter coated by undergoing treatment on its outer surface with boron 3 in step 106.Finally, the boron 3-coated outer surface of the green body 2 is consolidated by sinteringto form the self-neutron shielding high density cemented carbide with a boronconcentration gradient 12 in step 108, which sintering may be performed by hot pressing(HP), by hot isostatic pressing (HIP), by spark plasma sintering (SPS), by high pressurehigh temperature (HPHT) sintering, by vacuum sintering, or by high pressure sintering(sinter-HIP).

[0097] Alternatively FIG. 3B depicts a flow diagram demonstrating the individualprocess steps of making a self-neutron shielding high density cemented carbide forneutron shielding in accordance with the present subject matter. FIG. 3B shows that instep 200, the process is initiated by blending a powder mixture in a milling liquid comprising powders forming hard constituents of a ceramic hard phase and an iron (Fe)-chromium (Cr) based metallic binder phase present in an amount of from about 0.20 wt.%to about 15.00 wt.% with a Cr amount in a range of from about 2 wt.% to about 18 wt.%based on a total weight of the Fe-Cr based metallic binder phase, with an organic binderto form a slurry blend. The formed slurry blend is next dried in step 202 by vacuum drying,air drying, freeze drying, or spray drying through atomization, followed by undergoingcompaction to form a green body 2 in step 204. The green body 2 is sintered to form theself-neutron shielding high density cemented carbide in step 206, which sintering may be performed by hot pressing (HP), by hot isostatic pressing (HIP), by spark plasma sintering (SPS), by high pressure high temperature (HPHT) sintering, by vacuum sintering, or byhigh pressure sintering (sinter-HIP). The sintered cemented carbide is finally coated onits outer surface with boron 3 to form a boron concentration gradient 12 on the outersurface of the sintered cemented carbide by heat treatment typically from about 1200°Cto about 1800°C in step 208, thus favorably providing the entirety of the positive benefitsdescribed previously.

[0098] It should however be understood, and stressed that the overall concept ofsintering generally falls under the standard umbrella of processes defined by depegging,solid state sintering, or liquid phase sintering, and ultimately cooling the sintered materialdown to ambient conditions after the sintering operation is fully complete. A personhaving ordinary skill in the art would know that the aforementioned steps in theconsolidation processes described before can be performed all at once in the sameconsolidation equipment. Alternatively, a person having ordinary skill in the art wouldalso know that they may equally be performed one straight after the other in differentconsolidation equipments.

[0099] TABLE 1 shows different self-neutron shielding cemented carbidecompositions with their green body 2 having undergone boron coating 3 on its outersurface, and subsequent sintering.

[0100] [TABLE 1]Sample WCW2C Cr Fe Cr in Binder (wt.%) (wt.%) (wt.%) (wt.%) binder (wt.%) (wt.%) A99.80 0.00 0.022 0.178 11.000 0.20B 97.40 0.00 0.286 2.314 11.000 2.60C 92.60 0.00 0.910 6.370 12.500 7.28D 90.20 0.00 0.450 9.310 4.600 9.76E 89.00 0.00 1.913 8.820 17.800 10.73F 85.40 0.00 1.985 12.348 13.800 14.33G 85.00 0.00 0.596 14.357 4.000 14.95EXAMPLES

[0101] The following examples are put forth so as to provide those of ordinary skillin the art with a complete disclosure and description of how to make and use thedescribed subject matter and are not intended to limit the scope of what the inventorsregard as their disclosure nor are they intended to represent that the experiments beloware all or the only experiments performed. Efforts have been made to ensure accuracy with respect to numbers used but some experimental errors and deviations should be accounted for. EXAMPLE 1

[0102] BORONIZED SELF-NEUTRON SHIELDING HIGH DENSITY CEMENTEDCARBIDE COMPOSITIONS WITH A CERAMIC HARD PHASE AND AN IRON (FE)-CHROMIUM (CR) BASED METALLIC BINDER PHASE WITH AN INCREASED CRAMOUNT DEMONSTRATE A SUPERIOR CORROSION RESISTANCE INCOMPARISON TO COMPARATIVE SAMPLES

[0103] Corrosion resistance tests were run to see if whether, (I) boronization of thesamples would positively affect the corrosion resistance, and whether, (II) increasing thechromium (Cr) amount in the binder would also positively affect the corrosion resistance. Corrosion measurements were conducted with a Gamry 1010E interface at 25±1ºC in anaerated electrolyte solution containing 3.56 wt.% of NaCl. A conventional three-electrodeset-up was used with a graphite counter electrode, and a saturated calomel electrode(SCE) as reference. The working electrode (i.e. samples with a polished surface down to 1 μm with a diamond suspension) was placed in a Teflon holder, thereby leaving an exposed surface area to the electrolyte solution of 0.785 cm2. The open circuit potential(OCP) was recorded for 1 hour, allowing steady state to take place beforepotentiodynamic measurements were conducted at 0.5mV / s. FIG. 5A shows apotentiodynamic scan for boronized, and non-boronized sample D seen in Table 1 inaccordance with the present subject matter. FIG. 5B shows a potentiodynamic scan forboronized, and non-boronized sample E seen in Table 1 in accordance with the presentsubject matter. FIG. 6A shows a potentiodynamic scan comparison for boronized sampleD with boronized sample E seen in Table 1 (i.e., similar amount of binder, and sample Ehad the highest amount of Cr) in accordance with the present subject matter. FIG. 6Bshows a potentiodynamic scan comparison for boronized sample G with boronizedsample D seen in Table 1 (i.e., similar amount of Cr, and sample D had less amount ofthe binder) in accordance with the present subject matter. Finally, FIG. 6C shows apotentiodynamic scan comparison for boronized sample F with boronized sample G seenin Table 1 (i.e., similar amount of binder, and sample F had a higher amount of Cr) inaccordance with the present subject matter. For the non-comparison potentiodynamicscans seen in FIGS. 5A-5B for sample D and Sample E seen in Table 1, data wasobtained from one sample without boronization treatment, and one boronized sample.For the comparison potentiodynamic scans seen in FIGS. 6A-6C, for the boronizedsample D with the boronized sample E; for the boronized sample G with the boronizedsample D; and for the boronized sample F with the boronized sample G seen in Table 1,data was equally obtained from one sample. For FIGS.5A-5B and FIGS.6A-6C, thecorrosion rate is shown on the y-axis with the unit shown as corrosion current densityA / cm2, and the potential unit is shown on the x-axis as mV vs. Saturated CalomelElectrode (SCE).

[0104] FIGS. 5A-5B demonstrate that the boronized sample D, and the boronizedsample E show a greater corrosion resistance in comparison to the non-boronized sampleD, and the non-boronized sample E. The determined corrosion current densities wereobserved to be higher for the non-boronized sample D, and the non-boronized sample Ein comparison to the boronized ones. This means that the corrosion-rates were higherfor the non-boronized sample D, and the non-boronized sample E. The corrosion potentialwas shifted to more anodic values (i.e. more noble) for the boronized samples. FIGS.6A-6C equally demonstrate that increasing the total Cr amount in the binder substantially leads to a better corrosion resistance.EXAMPLE 2

[00105] NON-BORONIZED SELF-NEUTRON SHIELDING HIGH DENSITYCEMENTED CARBIDE COMPOSITIONS WITH A CERAMIC HARD PHASE AND AN IRON (FE)-CHROMIUM (CR) BASED METALLIC BINDER PHASE DEMONSTRATE A ROBUST HV30 HARDNESS AND FRACTURE TOUGHNESS

[0106] [TABLE 2]Sample WCW2C Cr WC: Fe Cr in BinderHV30 KlcDensity (wt.%) (wt.%) (wt.%) W2C (wt.%) binder (wt.%) (MPa (g / cm3) ratio (wt.%) √m) (wt.%)A 99.80 0.00 0.022 - 0.178 11.000 0.20 1343 4.9 13.50B 97.40 0.00 0.286 - 2.314 11.000 2.60 2453 6.8 14.70A1 83.91 5.69 1.671 15:1 8.497 16.433 10.16 2137 7.2 14.10B1 77.02 13.60 0.255 6:1 9.116 2.717 9.37 2062 7.4 14.36C1 86.26 20.01 0.284 4:1 13.452 2.069 13.73 1889 7.5 14.28

[0107] TABLE 2 shows non-boronized sample A, and sample B, sample A1,sample B1, and sample C1, which include a Fe-Cr based metallic binder having a weight ranging from 0.20 wt.% to 13.73 wt.%, WC having a weight spanning from 97.40 wt.% to99.80 wt.%, and W2C having a weight spanning from 5.69 wt.% to 20.01 wt.%.

[0108] HV30 Vickers hardness, and Palmqvist fracture toughness (Klc)measurements were determined in accordance with ISO 28079:2009 for the non- boronized cemented carbides as described herein. Three indentations per material were performed at 30 kgf using a Vickers limited equipment. The indentation diagonals, andthe crack lengths emerging from the indentation corners were measured with a light optical microscope at a magnification of 500X.

[0109] As demonstrated in TABLE 2, the obtained HV30 Vickers hardness valuesfor the non-boronized tested sample A, sample B, sample A1, sample B1, and sample C1range from 1343 HV30 to 2453 HV30. On the other hand, the obtained Palmqvist fracturetoughness (KIc) values for the tested non-boronized sample A, sample B, sample A1,sample B1, and sample C1 demonstrate a range of from 4.9 MPa√m to 7.5 MPa√m, witha density defined by a range of from 13.50 g / cm3to 14.70 g / cm3. EXAMPLE 3

[0110] BORONIZED SELF-NEUTRON SHIELDING HIGH DENSITYCEMENTED CARBIDE COMPOSITIONS WITH A CERAMIC HARD PHASE AND AN IRON (FE)-CHROMIUM (CR) BASED METALLIC BINDER PHASE DEMONSTRATE INCREASED HV1 HARDNESS COMPARED TO NON-BORONIZED SELF-NEUTRON SHIELDING HIGH DENSITY CEMENTED CARBIDE COMPOSITIONS

[0111] [TABLE 3]Sample HV1 - HV1 - Non-Boronized boronized D1661 1609E 2046 1946F 1891 1608G 1427 1274

[0112] TABLE 3 shows sample D, sample E, sample F, and sample G with theirgreen body 2 having undergone boron coating 3 on their outer surface, and subsequentsintering, and their equivalent non-boronized forms used as controls for comparison purposes.

[0113] HV1 Vickers hardness measurements were determined in accordance withISO 28079:2009 for cemented carbides as described herein. Fifteen indentations per material were performed at 1 kgf using a Vickers limited equipment. The indentationdiagonals, and the crack lengths emerging from the indentation corners were measuredwith a light optical microscope at a magnification of 500X.

[0114] As demonstrated in TABLE 3, the obtained HV1 Vickers hardness valuesfor the boronized sample D, sample E, sample F, and sample G range from 1427 HV1 to2046 HV 1, while the HV1 Vickers hardness values for the non-boronized forms of sampleD, sample E, sample F, and sample G span from 1274 HV1 to 1946 HV1. For each ofsample D, sample E, sample F, and sample G, the boronized form of the samplesdemonstrated a significantly greater HV1 Vickers hardness when compared to its non-boronized form, i.e. thus an improvement in HV1 Vickers hardness from about 1.4% toabout 17.6%.

[0115] Specifically for the boronized sample D, sample E, sample F, and sampleG, the HV1 Vickers hardness was further obtained as a function of the boronizationdistance to the surface (mm) of the material as shown in FIGS.4A-4D. FIGS.4A-4Ddemonstrate that the HV1 Vickers hardness consecutively drops as the boronizeddistance gets farther from the surface (mm) of the material. Thus, as demonstrated inFIGS.4A-4D, the HV1 Vickers hardness inversely correlates with the boronizationdistance to the surface (mm) of the material. In sum, FIG. 2B and FIGS.4A-4D, togetherin combination, show that the HV1 Vickers hardness positively correlates with theformation of the boron concentration gradient 12.

[0116] Although the present disclosure has been described in connection withexamples thereof, it will be appreciated by those skilled in the art that additions, deletions,modifications, and substitutions not specifically described may be made without departurefrom the spirit and scope of the disclosure as defined in the appended claims.

[0117] With respect to the use of substantially any plural and / or singular termsherein, those having skill in the art can translate from the plural to the singular and / or from the singular to the plural as is appropriate to the context and / or application. The various singular / plural permutations are not expressly set forth herein for sake of clarity.

[0118] The herein described subject matter sometimes illustrates differentcomponents contained within, or connected with, different other components. It is to be understood that such depicted architectures are merely exemplary, and that in fact many other architectures may be implemented which achieve the same functionality. In aconceptual sense, any arrangement of components to achieve the same functionality is effectively “associated” such that the desired functionality is achieved. Hence, any two components herein combined to achieve a particular functionality can be seen as “associated with” each other such that the desired functionality is achieved, irrespective of architectures or intermedial components. Likewise, any two components so associated can also be viewed as being “operably connected”, or “operably coupled,” to each other to achieve the desired functionality, and any two components capable of being so associated can also be viewed as being “operably couplable,” to each other to achieve the desired functionality. Specific examples of operably couplable include but are not limited to physically mateable and / or physically interacting components, and / or wirelessly interactable, and / or wirelessly interacting components, and / or logically interacting, and / or logically interactable components.

[0119] In some instances, one or more components may be referred to herein as“configured to,” “configured by,” “configurable to,” “operable / operative to,” “adapted / adaptable,” “able to,” “conformable / conformed to,” etc. Those skilled in the art will recognize that such terms (e.g., “configured to”) can generally encompass active- state components and / or inactive-state components and / or standby-state components, unless context requires otherwise.

[0120] While particular aspects of the present subject matter described hereinhave been shown and described, it will be apparent to those skilled in the art that, based upon the teachings herein, changes and modifications may be made without departing from the subject matter described herein and its broader aspects and, therefore, the appended claims are to encompass within their scope all such changes and modifications as are within the true spirit and scope of the subject matter described herein. It will be understood by those within the art that, in general, terms used herein, and especially in the appended claims (e.g., bodies of the appended claims) are generally intended as “open” terms (e.g., the term “including” should be interpreted as “including but not limited to,” the term “having” should be interpreted as “having at least,” the term “includes” should be interpreted as “includes but is not limited to,” etc.).

[0121] It will be further understood by those within the art that if a specific numberof an introduced claim recitation is intended, such an intent will be explicitly recited in the claim, and in the absence of such recitation no such intent is present. For example, as an aid to understanding, the following appended claims may contain usage of the introductory phrases “at least one” and “one or more” to introduce claim recitations. However, the use of such phrases should not be construed to imply that the introduction of a claim recitation by the indefinite articles “a” or “an” limits any particular claim containing such introduced claim recitation to claims containing only one such recitation, even when the same claim includes the introductory phrases “one or more” or “at least one” and indefinite articles such as “a” or “an” (e.g., “a” and / or “an” should typically be interpreted to mean “at least one” or “one or more”); the same holds true for the use of definite articles used to introduce claim recitations.

[0122] In addition, even if a specific number of an introduced claim recitation isexplicitly recited, those skilled in the art will recognize that such recitation should typically be interpreted to mean at least the recited number (e.g., the bare recitation of “two recitations,” without other modifiers, typically means at least two recitations, or two or more recitations).

[0123] Furthermore, in those instances where a convention analogous to “at leastone of A, B, and C, etc.” is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., “ a system having at least one of A, B, and C” would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and / or A, B, andC together, etc.). In those instances where a convention analogous to “at least one of A,B, or C, etc.” is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., “ a system having at least one of A, B, or C” would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and / or A, B, and C together, etc.). It will be further understood by those within the art that typically a disjunctive word and / or phrase presenting two or more alternative terms, whether in the description, claims, or drawings, should be understood to contemplate the possibilities of including one of theterms, either of the terms, or both terms unless context dictates otherwise. For example, the phrase “A or B” will be typically understood to include the possibilities of “A” or “B” or “A and B.”

[0124] With respect to the appended claims, those skilled in the art will appreciatethat recited operations therein may generally be performed in any order. Also, although various operational flows are presented in a sequence(s), it should be understood that the various operations may be performed in other orders than those which are illustrated or may be performed concurrently. Examples of such alternate orderings may include overlapping, interleaved, interrupted, reordered, incremental, preparatory, supplemental, simultaneous, reverse, or other variant orderings, unless context dictates otherwise. Furthermore, terms like “responsive to,” “related to,” or other past-tense adjectives are generally not intended to exclude such variants, unless context dictates otherwise.

[0125] Those skilled in the art will appreciate that the foregoing specific exemplaryprocesses and / or devices and / or technologies are representative of more general processes and / or devices and / or technologies taught elsewhere herein, such as in theclaims filed herewith and / or elsewhere in the present application.

[0126] While various aspects and examples have been disclosed herein, otheraspects and examples will be apparent to those skilled in the art. The various aspectsand examples disclosed herein are for purposes of illustration and are not intended to belimiting, with the true scope and spirit being indicated by the following claims.

[0127] The illustrative examples described in the detailed description, drawings,and claims are not meant to be limiting. Other examples may be utilized, and otherchanges may be made, without departing from the spirit or scope of the subject matter presented here.

[0128] Where a range of values is provided, it is understood that each interveningvalue, to the tenth of the unit of the lower limit unless the context clearly dictates otherwise, between the upper and lower limit of that range and any other stated or intervening value in that stated range is encompassed within the disclosure. The upper and lower limits of these smaller ranges which can independently be included in thesmaller ranges is also encompassed within the disclosure, subject to any specifically excluded limit in the stated range. Where the stated range includes one or both of the limits, ranges excluding both of those included limits are also included in the disclosure.

[0129] One skilled in the art will recognize that the herein described components(e.g., operations), devices, objects, and the discussion accompanying them are used as examples for the sake of conceptual clarity and that various configuration modifications are contemplated. Consequently, as used herein, the specific exemplars set forth and the accompanying discussion are intended to be representative of their more general classes. In general, use of any specific exemplar is intended to be representative of its class, and the non-inclusion of specific components (e.g., operations), devices, andobjects should not be taken as limiting.

[0130] Additionally, for example any sequence(s) and / or temporal order ofsequence of the system and method that are described herein this disclosure are illustrative and should not be interpreted as being restrictive in nature. Accordingly, it should be understood that the process steps may be shown and described as being in a sequence or temporal order, but they are not necessarily limited to being carried out in any particular sequence or order. For example, the steps in such processes or methods generally may be carried out in various different sequences and orders, while still falling within the scope of the present disclosure.

[0131] Finally, the discussed application publications and / or patents herein areprovided solely for their disclosure prior to the filing date of the described disclosure.Nothing herein should be construed as an admission that the described disclosure is notentitled to antedate such publication by virtue of prior disclosure.

Claims

What is claimed is:

1. A cemented carbide composition, comprising:a ceramic hard phase; an iron (Fe)-chromium (Cr) based metallic binder phase present in an amount offrom about 0.20 wt.% to about 15.00 wt.% based on a total weight of the cementedcarbide composition with a Cr amount in a range of from about 2 wt.% to about 18 wt.%based on a total weight of the Fe-Cr based metallic binder phase; and a boron concentration gradient.

2. The cemented carbide composition of claim 1, wherein the ceramic hard phasecomprises tungsten carbide (WC), sub-stoichiometric ditungsten carbide (W2C), or acombination thereof.

3. The cemented carbide composition of claim 2, wherein the ceramic hard phase comprises WC.

4. The cemented carbide composition of claim 2, wherein the ceramic hard phasecomprises sub-stoichiometric W2C.

5. The cemented carbide composition of claim 2, wherein the ceramic hard phasecomprises a combination of WC and sub-stoichiometric W2C in a ratio of from about 4:1to about 15:1.

6. The cemented carbide composition of claim 1, wherein the cemented carbidecomposition comprises from about 85.00 wt.% to about 99.80 wt.% of the ceramic hardphase based on a total weight of the cemented carbide composition.

7. The cemented carbide composition of claim 1, wherein the Fe-Cr based metallicbinder phase is made by blending a FeCr powder with a Cr3C2 powder, a Fe powder witha Cr3C2powder, or a Fe powder with a Cr powder.

8. The cemented carbide composition of claim 1, wherein the cemented carbidecomposition has an HV1 Vickers hardness in a range of from about 1430 HV1 to about 2045 HV1.

9. An object, comprising a cemented carbide composition of claim 1 used for neutron shielding.

10. A method of making a sintered cemented carbide, comprising:blending a powder mixture in a milling liquid comprising powders forming hardconstituents of a ceramic hard phase and an iron (Fe)-chromium (Cr) based metallicbinder phase present in an amount of from about 0.20 wt.% to about 15.00 wt.% havinga Cr amount in a range of from about 2 wt.% to about 18 wt.% based on a total weight ofthe Fe-Cr based metallic binder phase, with an organic binder to form a slurry blend;drying the slurry blend to form a powder blend; compacting the formed powder blend to form a green body; coating an outer surface of the formed green body with a boron-containing agent;and sintering the coated green body to form a boron concentration gradient on the outersurface of the green body.

11. The method of making a sintered cemented carbide of claim 10, wherein theceramic hard phase comprises tungsten carbide (WC), sub-stoichiometric ditungstencarbide (W2C), or a combination thereof.

12. The method of making a sintered cemented carbide of claim 11, wherein theceramic hard phase comprises WC.

13. The method of making a sintered cemented carbide of claim 11, wherein theceramic hard phase comprises sub-stoichiometric W2C.

14. The method of making a sintered cemented carbide of claim 11, wherein theceramic hard phase comprises a combination of WC and sub-stoichiometric W2C in a ratio of from about 4:1 to about 15:1.

15. The method of making a sintered cemented carbide of claim 10, wherein thecemented carbide comprises from about 85.00 wt.% to about 99.80 wt.% of the ceramichard phase based on a total weight of the cemented carbide.

16. The method of making a sintered cemented carbide of claim 10, wherein acemented carbide with improved corrosion resistance is obtained.

17. The method of making a sintered cemented carbide of claim 10, wherein the Fe-Cr based metallic binder phase is made by blending a FeCr powder with a Cr3C2 powder,a Fe powder with a Cr3C2 powder, or a Fe powder with a Cr powder.

18. The method of making a sintered cemented carbide of claim 10, wherein thecemented carbide has an HV1 Vickers hardness in a range of from about 1430 HV1 to about 2045 HV1.

19. The method of making a sintered cemented carbide of claim 10, wherein the dryingthe slurry blend comprises vacuum drying, air drying, freeze drying, or spray drying through atomization.

20. The method of making a sintered cemented carbide of claim 10, wherein thesintering comprises hot pressing (HP), hot isostatic pressing (HIP), spark plasma sintering(SPS), vacuum sintering, high pressure sintering (sinter-HIP), or high-pressure hightemperature (HPHT) sintering.

21. The method of making a sintered cemented carbide of claim 10, wherein the boron-containing agent is at least one of boron, boron nitride (BN), or a combination thereof.

22. The method of making a sintered cemented carbide of claim 21, further comprising optionally removing any unreacted boron-containing agent after the sintering.

23. A method of making a sintered cemented carbide, comprising:blending a powder mixture in a milling liquid comprising powders forming hard constituents of a ceramic hard phase and an iron (Fe)-chromium (Cr) based metallicbinder phase present in an amount of from about 0.20 wt.% to about 15.00 wt.% havinga Cr amount in a range of from about 2 wt.% to about 18 wt.% based on a total weight ofthe Fe-Cr based metallic binder phase, with an organic binder to form a slurry blend; drying the slurry blend to form a powder blend; compacting the formed powder blend to form a green body; sintering the green body to form the sintered cemented carbide; and coating an outer surface of the sintered cemented carbide with a boron-containingagent to form a boron concentration gradient on the outer surface of the sinteredcemented carbide by heat treatment.

24. The method of making a sintered cemented carbide of claim 23, wherein the ceramic hard phase comprises tungsten carbide (WC), sub-stoichiometric ditungsten carbide (W2C), or a combination thereof.

25. The method of making a sintered cemented carbide of claim 24, wherein the ceramic hard phase comprises WC.

26. The method of making a sintered cemented carbide of claim 24, wherein theceramic hard phase comprises sub-stoichiometric W2C.

27. The method of making a sintered cemented carbide of claim 24, wherein theceramic hard phase comprises a combination of WC and sub-stoichiometric W2C in a ratio of from about 4:1 to about 15:1.

28. The method of making a sintered cemented carbide of claim 23, wherein thecemented carbide comprises from about 85.00 wt.% to about 99.80 wt.% of the ceramichard phase based on a total weight of the cemented carbide.

29. The method of making a sintered cemented carbide of claim 23, wherein the Fe-Cr based metallic binder phase is made by blending a FeCr powder with a Cr3C2 powder, a Fe powder with a Cr3C2 powder, or a Fe powder with a Cr powder.

30. The method of making a sintered cemented carbide of claim 23, wherein the cemented carbide has an HV1 Vickers hardness in a range of from about 1430 HV1 to about 2045 HV1.

31. The method of making a sintered cemented carbide of claim 23, wherein the dryingthe slurry blend comprises vacuum drying, air drying, freeze drying, or spray drying through atomization.

32. The method of making a sintered cemented carbide of claim 23, wherein thesintering comprises hot pressing (HP), hot isostatic pressing (HIP), spark plasma sintering (SPS), vacuum sintering, high pressure sintering (sinter-HIP), or high-pressure high temperature (HPHT) sintering.

33. The method of making a sintered cemented carbide of claim 23, wherein the boron-containing agent is at least one of boron, boron nitride (BN), or a combination thereof.

34. The method of making a sintered cemented carbide of claim 23, wherein the heattreatment to form the boron concentration gradient on the outer surface of the sintered cemented carbide is performed at a temperature range of from about 1200°C to about 1800°C.

35. The method of making a sintered cemented carbide of claim 33, further comprisingoptionally removing any unreacted boron-containing agent after the heat treatment.

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