Scientific factors involved in designing mechanically superhard compounds (e.g., Vickers Hardness ≥40 GPa) can be complex. In some instances, factors such as elastic deformations (reflected in bulk modulus and shear resistance) and plastic deformations (reflected in elastic limits) are modulated to optimize a superhard compound. In some cases, there are about five intrinsically superhard compounds: diamond, cubic boron nitride, rhenium diboride, tungsten tetraboride, and iron tetraboride.
Disclosed herein, in certain embodiments, are metal compositions, methods, tools and abrasive materials comprising tungsten, boron, and a non-radioactive Group V Transition Metal.
In certain embodiments, provided herein is a metal composition of Formula (I) crystallized in an orthorhombic phase,
W1-xNxB Formula I
wherein N is a non-radioactive Group V Transition Metal; and x has a value within the range 0.01 to 0.99, inclusively.
In certain embodiments, provided herein is a metal composition of Formula (I):
W1-xNxB Formula I
wherein N is a non-radioactive Group V Transition Metal; and x has a value within the range 0.01 to 0.99, inclusively; and wherein the metal composition has at least one plane that exhibits a strain hardening effect when subjected to a pressure sufficient to induce strain hardening.
In certain embodiments, provided herein is a metal composition of Formula (I):
W1-xNxB Formula I
wherein N is a non-radioactive Group V Transition Metal; and x has a value within the range 0.01 to 0.99, inclusively; and wherein boron forms a plurality of chains within a crystal structure of the metal composition, and wherein each of the plurality of chains is aligned along a same axis of the crystal structure.
In certain embodiments, provided herein is a method of making a stable metal composition comprising introducing a plurality of additive particles into the interstices of a metal composition precursor to form a metal composition, wherein the plurality of additive particles is selected from vanadium, niobium, and tantalum; and subjecting the metal composition to a temperature and pressure at which the metal composition is stable at room temperature.
All publications, patents, and patent applications mentioned in this specification are herein incorporated by reference to the same extent as if each individual publication, patent, or patent application was specifically and individually indicated to be incorporated by reference.
The novel features of the invention are set forth with particularity in the appended claims. A better understanding of the features and advantages of the present invention will be obtained by reference to the following detailed description that sets forth illustrative embodiments, in which the principles of the invention are utilized, and the accompanying drawings of which:
Superhard compounds can be compounds that have a Vickers hardness value of about or greater than 40 gigapascals (GPa). In some instances, superhard compounds can be designed rather than discovered by following, for example, two rules. The first rule or step can be to start with a starting material of high valence electron density, leading to a large bulk modulus and high incompressibility. The second rule or step can be to add short, strong covalent bonds to prevent shear and slipping of planes. For example, diamond is both the hardest and stiffest single-phase material known with a hardness of 70-110 GPa, a bulk modulus of 442 GPa, and a valence electron density of 0.71 e−Å−3 (8). Similarly, utilizing the aforementioned design rules to generate superhard metals comprising for example tungsten and boron can result in high borides in a tungsten metal composition and/or heavy covalent tungsten compounds with less metallic characteristics relative to a WB composition. For example, to generate a heavy metal tungsten, one method can be by introducing at least four molar equivalents of boron to yield WB4. In such cases, this can increase covalent bonding, and can result in a superhard composition.
With the lower borides of tungsten, a lower level of covalent bonding in some instances results in a softer material. For example, pristine tungsten tetraboride, the highest boride in the W—B system, is superhard with a Vickers Hardness of ˜43 GPa under a load of 0.5 N. Experimental hardness measurements have shown that pristine WB is not naturally superhard, with single crystals exhibiting a Vickers Hardness of ˜26 GPa under a load of 1 N and polycrystalline materials ˜36 GPa. Computational studies have shown that WB can have a high shear modulus, although lower than those found in superhard materials such as WB4. Furthermore, in tungsten monoboride, the tungsten-tungsten bond distance (2.8 angstroms) approaches that of pure tungsten metal (2.7 angstroms), which suggests a stronger metallic character. This brings with it some of the malleability and toughness found in conventional metals. Indeed, WB is suggested to be a balance between hardness and ductility, which can lead to high wear resistance.
Because of the higher metallic character, metallic bonding can play a greater role in the mechanical properties of tungsten monoboride. However, metallic bonding can be weak. For example, metals, while possessing high electron density and incompressibility, possess metallic bonds which are non-directional. Lack of directional bonding allows for bonds to break and dislocations to form, leading to a ductile and malleable metal. In some instances, one method of increasing the hardness of metallic tungsten monoboride can be to add more equivalents of boron to yield a more covalent tungsten tetraboride.
In some embodiments, described herein is an alternative approach of generating a tungsten monoboride with superhard metal properties. In some instances, this is achieved by selectively tuning specific crystallographic planes to increase the hardness of tungsten monoboride to become superhard. More specifically, this can be accomplished through solid-solution strengthening of the metallic tungsten planes of tungsten monoboride with a non-radioactive Group V Transition Metal (e.g., tantalum).
In certain embodiments, provided herein is a metal composition of Formula (I) crystallized in an orthorhombic phase,
W1-xNxB Formula I
wherein N is a non-radioactive Group V Transition Metal; and x has a value within the range 0.01 to 0.99, inclusively.
In some embodiments, N is Tantalum (Ta). In some embodiments, N is Vanadium (V). In some embodiments, N is Niobium (Nb). In some embodiments, x has a value within the range 0.05 to 0.95, inclusively. In some embodiments, x has a value within the range 0.1 to 0.9, inclusively. In some embodiments, x has a value within the range 0.1 to 0.6, 0.2 to 0.6, 0.3 to 0.6, or 0.4 to 0.6, inclusively. In some embodiments, x has a value within the range 0.2 to 0.55, 0.3 to 0.55, 0.4 to 0.55, or 0.45 to 0.55, inclusively. In some embodiments, x has a value within the range 0.1 to 0.5, 0.2 to 0.5, 0.3 to 0.5, or 0.4 to 0.5, inclusively. In some embodiments, x has a value of about 0.5. In some embodiments, the metal composition is a metal composition of Formula (Ia) crystallized in an orthorhombic phase,
W1-xTaxB Formula Ia
wherein x has a value within the range 0.01 to 0.99, inclusively.
In some embodiments, x has a value within the range 0.05 to 0.95, inclusively. In some embodiments, x has a value within the range 0.1 to 0.6, 0.2 to 0.6, 0.3 to 0.6, or 0.4 to 0.6, inclusively. In some embodiments, x has a value within the range 0.2 to 0.55, 0.3 to 0.55, 0.4 to 0.55, or 0.45 to 0.55, inclusively. In some embodiments, x has a value within the range 0.1 to 0.5, 0.2 to 0.5, 0.3 to 0.5, or 0.4 to 0.5, inclusively. In some embodiments, x has a value of about 0.5. In some embodiments, the metal composition has a bulk modulus of from about 336 GPa to about 346 GPa. In some embodiments, the metal composition has a hardness of about 33, about 34, about 35, about 36, about 37, or about 38 GPa. In some embodiments, the metal composition has at least one plane that exhibits a strain hardening effect when subjected to a pressure sufficient to induce strain hardening. In some embodiments, at least one plane of the metal composition further exhibits a discontinuous increase in directional incompressibility. In some embodiments, boron forms a chain within the crystalline structure of the metal composition, and the chain is aligned along a c-axis of the crystalline structure. In some embodiments, the chain of boron does not alternate to form a perpendicular array within the structure.
In some embodiments, the metal composition is a metal composition of Formula (Ib) crystallized in an orthorhombic phase,
W1-xNbxB Formula Ib
wherein x has a value within the range 0.01 to 0.99, inclusively.
In some embodiments, the metal composition is a metal composition of Formula (Ic) crystallized in an orthorhombic phase,
W1-xNbxB Formula Ic
wherein x has a value within the range 0.01 to 0.99, inclusively.
In certain embodiments, provided herein is a metal composition of Formula (I):
W1-xNxB Formula I
wherein N is a non-radioactive Group V Transition Metal; and x has a value within the range 0.01 to 0.99, inclusively; and wherein the metal composition has at least one plane that exhibits a strain hardening effect when subjected to a pressure sufficient to induce strain hardening.
In some embodiments, N is Tantalum (Ta). In some embodiments, N is Vanadium (V). In some embodiments, N is Niobium (Nb). In some embodiments, x has a value within the range 0.05 to 0.95, inclusively. In some embodiments, x has a value within the range 0.1 to 0.9, inclusively. In some embodiments, x has a value within the range 0.1 to 0.6, 0.2 to 0.6, 0.3 to 0.6, or 0.4 to 0.6, inclusively. In some embodiments, x has a value within the range 0.2 to 0.55, 0.3 to 0.55, 0.4 to 0.55, or 0.45 to 0.55, inclusively. In some embodiments, x has a value within the range 0.1 to 0.5, 0.2 to 0.5, 0.3 to 0.5, or 0.4 to 0.5, inclusively. In some embodiments, x has a value of about 0.5. In some embodiments, at least one plane of the metal composition further exhibits a discontinuous increase in directional incompressibility. In some embodiments, the metal composition is crystallized in an orthorhombic phase. In some embodiments, the metal composition has a bulk modulus of from about 336 GPa to about 346 GPa. In some embodiments, the metal composition has a hardness of about 33, about 34, about 35, about 36, about 37, or about 38 GPa. In some embodiments, boron forms a chain within the crystalline structure of the metal composition, and the chain is aligned along a c-axis of the crystalline structure. In some embodiments, the chain of boron does not alternate to form a perpendicular array within the structure.
In certain embodiments, provided herein is a metal composition of Formula (I):
W1-xNxB Formula I
wherein N is a non-radioactive Group V Transition Metal; and x has a value within the range 0.01 to 0.99, inclusively; and wherein boron forms a plurality of chains within a crystal structure of the metal composition, and wherein each of the plurality of chains is aligned along a same axis of the crystal structure.
In some embodiments, N is Tantalum (Ta). In some embodiments, N is Vanadium (V). In some embodiments, N is Niobium (Nb). In some embodiments, x has a value within the range 0.05 to 0.95, inclusively. In some embodiments, x has a value within the range 0.1 to 0.9, inclusively. In some embodiments, x has a value within the range 0.1 to 0.6, 0.2 to 0.6, 0.3 to 0.6, or 0.4 to 0.6, inclusively. In some embodiments, x has a value within the range 0.2 to 0.55, 0.3 to 0.55, 0.4 to 0.55, or 0.45 to 0.55, inclusively. In some embodiments, x has a value within the range 0.1 to 0.5, 0.2 to 0.5, 0.3 to 0.5, or 0.4 to 0.5, inclusively. In some embodiments, x has a value of about 0.5. In some embodiments, the metal composition is crystallized in an orthorhombic phase. In some embodiments, the metal composition has a bulk modulus of from about 336 GPa to about 346 GPa. In some embodiments, the metal composition has a hardness of about 33, about 34, about 35, about 36, about 37, or about 38 GPa. In some embodiments, the metal composition has at least one plane that exhibits a strain hardening effect when subjected to a pressure sufficient to induce strain hardening. In some embodiments, at least one plane of the metal composition further exhibits a discontinuous increase in directional incompressibility. In some embodiments, the axis is the c-axis. In some embodiments, the chain of boron does not alternate to form a perpendicular array within the structure.
In certain embodiments, provided herein is a method of making a stable metal composition comprising (a) introducing a plurality of additive particles into the interstices of a metal composition precursor to form a metal composition, wherein the plurality of additive particles is selected from vanadium, niobium, and tantalum; and (b) subjecting the metal composition to a temperature and pressure at which the metal composition is stable at room temperature. In some embodiments, the metal composition precursor comprises a tungsten and boron molecule of formula WB. In some embodiments, the subjecting further comprises sintering the metal composition precursor with the plurality of additive particles to form the stable metal composition. In some embodiments, the stable metal composition has the formula W1-xNxB, wherein N is an additive particle selected from vanadium, niobium, and tantalum and x has a value within the range 0.01 to 0.99, inclusively. In some embodiments, x has a value within the range 0.05 to 0.95, inclusively. In some embodiments, x has a value within the range 0.1 to 0.9, inclusively. In some embodiments, x has a value within the range 0.1 to 0.6, 0.2 to 0.6, 0.3 to 0.6, or 0.4 to 0.6, inclusively. In some embodiments, x has a value within the range 0.2 to 0.55, 0.3 to 0.55, 0.4 to 0.55, or 0.45 to 0.55, inclusively. In some embodiments, x has a value within the range 0.1 to 0.5, 0.2 to 0.5, 0.3 to 0.5, or 0.4 to 0.5, inclusively. In some embodiments, x has a value of about 0.5. In some embodiments, the additive particle is tantalum. In some embodiments, the stable metal composition is crystallized in an orthorhombic phase. In some embodiments, the stable metal composition has a bulk modulus of from about 336 GPa to about 346 GPa. In some embodiments, the stable metal composition has a hardness of about 33, about 34, about 35, about 36, about 37, or about 38 GPa. In some embodiments, the stable metal composition has at least one plane that exhibits a strain hardening effect when subjected to a pressure sufficient to induce strain hardening. In some embodiments, at least one plane of the stable metal composition further exhibits a discontinuous increase in directional incompressibility. In some embodiments, boron forms a chain within the structure of the metal composition and is aligned along one axis of the structure. In some embodiments, the axis is the c-axis. In some embodiments, the chain of boron does not alternate to form a perpendicular array within the structure. In some embodiments, the stable metal composition is an entropically stable metal composition.
In certain embodiments, provided herein is a tool comprising a surface for cutting or abrading, said surface being a surface of a metal composition disclosed above.
In certain embodiments, provided herein is an abrasive material comprising a plurality of abrasive particles, each being a metal composition disclosed above.
In certain embodiments, provided herein is a method of making a tool, comprising (a) providing a powder comprising a plurality of metal composition particles, wherein the plurality of metal composition particles comprise metal compositions disclosed above; and compressing said powder to form a self-supporting structure.
In some embodiments, described herein is a metal composition of Formula (I) crystallized in an orthorhombic phase,
W1-xNxB Formula I
wherein N is a non-radioactive Group V Transition Metal; and x has a value within the range 0.01 to 0.99, inclusively.
In some embodiments, also described herein is a metal composition of Formula (I):
W1-xNxB Formula I
wherein N is a non-radioactive Group V Transition Metal; and x has a value within the range 0.01 to 0.99, inclusively; and wherein the metal composition has at least one plane that exhibits a strain hardening effect when subjected to a pressure sufficient to induce strain hardening.
In some embodiments, further described herein is a metal composition of Formula (I):
W1-xNxB Formula I
wherein N is a non-radioactive Group V Transition Metal; and x has a value within the range 0.01 to 0.99, inclusively; and wherein boron forms a chain within the structure of the metal composition and is aligned along one axis of the structure.
In some embodiments, additionally described herein include a method of making a stable metal composition comprising: (a) introducing a plurality of additive particles into the interstices of a metal composition precursor to form a metal composition, wherein the plurality of additive particles is selected from vanadium, niobium, and tantalum; and (b) subjecting the metal composition to a temperature and pressure at which the metal composition is stable at room temperature.
In some embodiments, the metal compositions of the present disclosure are easy to synthesize. In addition, these metal compositions can be made at ambient pressure and thus can be cast from the melt like common metals. Furthermore, their metallic character allows them to be easily cut and shaped post-synthesis by electric discharge machining.
In some embodiments, described herein also include tools and abrasive materials comprising a metal composition described herein and methods of making such tools.
In certain embodiments, disclosed herein include metal compositions, stable metal compositions, methods of making the metal compositions, tools for cutting or abrading, or abrasive materials comprising the metal compositions. In some embodiments, described herein include a metal composition of Formula (I) crystallized in an orthorhombic phase,
W1-xNxB Formula I
wherein N is a non-radioactive Group V Transition Metal; and x has a value within the range 0.01 to 0.99, inclusively.
Sometimes, x can have a value within the range 0.05 to 0.95, inclusively. Sometimes, x can have a value within the range 0.1 to 0.9, 0.1 to 0.6, 0.2 to 0.6, 0.3 to 0.6, 0.4 to 0.6, 0.2 to 0.55, 0.3 to 0.55, 0.4 to 0.55, 0.45 to 0.55, 0.1 to 0.5, 0.2 to 0.5, 0.3 to 0.5, 0.4 to 0.5, 0.5 to 0.55, or 0.45 to 0.5, inclusively. In some cases, x has a value within the range 0.1 to 0.9, inclusively. In some instances, x has a value within the range 0.1 to 0.6, 0.2 to 0.6, 0.3 to 0.6, or 0.4 to 0.6, inclusively. In some instances, x has a value within the range 0.2 to 0.55, 0.3 to 0.55, 0.4 to 0.55, or 0.45 to 0.55, inclusively. In additional instances, x has a value within the range 0.1 to 0.5, 0.2 to 0.5, 0.3 to 0.5, or 0.4 to 0.5, inclusively.
In some cases, x has a value of about 0.05, 0.1, 0.15, 0.2, 0.25, 0.3, 0.35, 0.4, 0.41, 0.42, 0.43, 0.44, 0.45, 0.46, 0.47, 0.48, 0.49, 0.5, 0.51, 0.52, 0.53, 0.54, 0.55, 0.56, 0.57, 0.58, 0.59, 0.6, 0.65, 0.7, 0.8, 0.9, or about 0.95. In some cases, x has a value of about 0.1. In some cases, x has a value of about 0.2. In some cases, x has a value of about 0.3. In some cases, x has a value of about 0.4. In some cases, x has a value of about 0.41. In some cases, x has a value of about 0.42. In some cases, x has a value of about 0.43. In some cases, x has a value of about 0.44. In some cases, x has a value of about 0.45. In some cases, x has a value of about 0.46. In some cases, x has a value of about 0.47. In some cases, x has a value of about 0.48. In some cases, x has a value of about 0.49. In some cases, x has a value of about 0.5. In some cases, x has a value of about 0.51. In some cases, x has a value of about 0.52. In some cases, x has a value of about 0.53. In some cases, x has a value of about 0.54. In some cases, x has a value of about 0.55. In some cases, x has a value of about 0.56. In some cases, x has a value of about 0.57. In some cases, x has a value of about 0.58. In some cases, x has a value of about 0.59. In some cases, x has a value of about 0.6.
In some embodiments, N is selected from Tantalum (Ta), Vanadium (V), and Niobium (Nb). In some instances, N is Tantalum (Ta). In some cases, N is Vanadium (V). In other cases, N is Niobium (Nb).
In some embodiments, a metal composition described herein is a metal composition of Formula (Ia) crystallized in an orthorhombic phase,
W1-xTaxB Formula Ia
in which x has a value within the range 0.01 to 0.99, inclusively.
Sometimes, x can have a value within the range 0.1 to 0.9, 0.1 to 0.6, 0.2 to 0.6, 0.3 to 0.6, 0.4 to 0.6, 0.2 to 0.55, 0.3 to 0.55, 0.4 to 0.55, 0.45 to 0.55, 0.1 to 0.5, 0.2 to 0.5, 0.3 to 0.5, 0.4 to 0.5, 0.5 to 0.55, or 0.45 to 0.5, inclusively. In some cases, x has a value within the range 0.1 to 0.9, inclusively. In some instances, x has a value within the range 0.1 to 0.6, 0.2 to 0.6, 0.3 to 0.6, or 0.4 to 0.6, inclusively. In some instances, x has a value within the range 0.2 to 0.55, 0.3 to 0.55, 0.4 to 0.55, or 0.45 to 0.55, inclusively. In additional instances, x has a value within the range 0.1 to 0.5, 0.2 to 0.5, 0.3 to 0.5, or 0.4 to 0.5, inclusively.
In some cases, x has a value of about 0.05, 0.1, 0.15, 0.2, 0.25, 0.3, 0.35, 0.4, 0.41, 0.42, 0.43, 0.44, 0.45, 0.46, 0.47, 0.48, 0.49, 0.5, 0.51, 0.52, 0.53, 0.54, 0.55, 0.56, 0.57, 0.58, 0.59, 0.6, 0.65, 0.7, 0.8, 0.9, or about 0.95. In some cases, x has a value of about 0.1. In some cases, x has a value of about 0.2. In some cases, x has a value of about 0.3. In some cases, x has a value of about 0.4. In some cases, x has a value of about 0.41. In some cases, x has a value of about 0.42. In some cases, x has a value of about 0.43. In some cases, x has a value of about 0.44. In some cases, x has a value of about 0.45. In some cases, x has a value of about 0.46. In some cases, x has a value of about 0.47. In some cases, x has a value of about 0.48. In some cases, x has a value of about 0.49. In some cases, x has a value of about 0.5. In some cases, x has a value of about 0.51. In some cases, x has a value of about 0.52. In some cases, x has a value of about 0.53. In some cases, x has a value of about 0.54. In some cases, x has a value of about 0.55. In some cases, x has a value of about 0.56. In some cases, x has a value of about 0.57. In some cases, x has a value of about 0.58. In some cases, x has a value of about 0.59. In some cases, x has a value of about 0.6.
In some embodiments, a metal composition described herein is a metal composition of formula W0.5Ta0.5B crystallized in an orthorhombic phase.
Sometimes, the metal composition can have a bulk modulus from about 336 GPa to about 346 GPa. Bulk modulus (K or B) can measure a material's resistance to uniform compression. In some cases, bulk modulus refers to the elastic modulus (also known as Young's modulus and tensile modulus) or elastic deformation behavior of a metal composition described herein.
In some instances, the metal composition has a hardness of about 33, about 34, about 35, about 36, about 37, or about 38 GPa. Hardness can be described as a measurement of how resistant a material is to permanent deformation when a compressive force is applied. Hardness can be modulated by factors such as for example, ductility, plasticity, elastic stiffness, strain, viscoelasticity, viscosity, or a combination thereof. In some instances, a hardness measurement comprises scratch, indentation, or rebound measurement. In some cases, a hardness measurement is an indentation measurement with an indentation hardness scale of Rockwell, Vickers, Shore, or Brinell. In some cases, an indentation measurement is a Vickers hardness test.
In some cases, the metal composition has at least one plane that exhibits a strain hardening effect when subjected to a pressure sufficient to induce strain hardening. Strain hardening (also known as work hardening or cold working) can be described as the strengthening of a material by plastic deformation. Plastic deformation can be an irreversible deformation of a material under an applied force.
In some cases, at least one plane of the metal composition further exhibits a discontinuous change (e.g, increase) in directional incompressibility. Compressibility can be a measure of the relative volume change of a material as a response to a pressure change. In the current case for example, a directional discontinuous change in incompressibility can refers to a change along one of the crystal lattice of a metal composition described herein. In some instances, a discontinuous change in directional incompressibility can be a discontinuous increase along one of the crystal lattice of a metal composition described herein. In some cases, a discontinuous increase in directional incompressibility can be along one of the crystal lattice of a metal composition described herein crystallized in an orthorhombic phase.
In some instances, boron forms a chain within the structure of the metal composition of Formula (Ia) and is aligned along one axis of the structure. For example, the axis can be the c-axis or the a-axis. In some cases, the axis is the c-axis. In some cases, the axis is the a-axis.
In some instances, the chain of boron does not alternate to form a perpendicular array within the structure, as can be observed in the tetrahedral phase.
In some embodiments, N is Vanadium (V) and the metal composition is a metal composition of Formula (Ib) crystallized in an orthorhombic phase,
W1-xVxB Formula Ib
in which x has a value within the range 0.01 to 0.99, inclusively.
Sometimes, x can have a value within the range 0.05 to 0.95, 0.1 to 0.9, 0.1 to 0.6, 0.2 to 0.6, 0.3 to 0.6, 0.4 to 0.6, 0.2 to 0.55, 0.3 to 0.55, 0.4 to 0.55, 0.45 to 0.55, 0.1 to 0.5, 0.2 to 0.5, 0.3 to 0.5, 0.4 to 0.5, 0.5 to 0.55, or 0.45 to 0.5, inclusively. In some cases, x has a value within the range 0.1 to 0.9, inclusively. In some instances, x has a value within the range 0.1 to 0.6, 0.2 to 0.6, 0.3 to 0.6, or 0.4 to 0.6, inclusively. In some instances, x has a value within the range 0.2 to 0.55, 0.3 to 0.55, 0.4 to 0.55, or 0.45 to 0.55, inclusively. In additional instances, x has a value within the range 0.1 to 0.5, 0.2 to 0.5, 0.3 to 0.5, or 0.4 to 0.5, inclusively.
In some cases, x has a value of about 0.05, 0.1, 0.15, 0.2, 0.25, 0.3, 0.35, 0.4, 0.41, 0.42, 0.43, 0.44, 0.45, 0.46, 0.47, 0.48, 0.49, 0.5, 0.51, 0.52, 0.53, 0.54, 0.55, 0.56, 0.57, 0.58, 0.59, 0.6, 0.65, 0.7, 0.8, 0.9, or about 0.95. In some cases, x has a value of about 0.1. In some cases, x has a value of about 0.2. In some cases, x has a value of about 0.3. In some cases, x has a value of about 0.4. In some cases, x has a value of about 0.41. In some cases, x has a value of about 0.42. In some cases, x has a value of about 0.43. In some cases, x has a value of about 0.44. In some cases, x has a value of about 0.45. In some cases, x has a value of about 0.46. In some cases, x has a value of about 0.47. In some cases, x has a value of about 0.48. In some cases, x has a value of about 0.49. In some cases, x has a value of about 0.5. In some cases, x has a value of about 0.51. In some cases, x has a value of about 0.52. In some cases, x has a value of about 0.53. In some cases, x has a value of about 0.54. In some cases, x has a value of about 0.55. In some cases, x has a value of about 0.56. In some cases, x has a value of about 0.57. In some cases, x has a value of about 0.58. In some cases, x has a value of about 0.59. In some cases, x has a value of about 0.6. In some cases, x has a value of about 0.7. In some cases, x has a value of about 0.8. In some cases, x has a value of about 0.9.
Sometimes, the metal composition can have a bulk modulus that is higher than the bulk modulus of a metal composition of Formula (Ib) crystallized in a tetragonal phase. Other times, the metal composition can have a bulk modulus that is lower than the bulk modulus of a metal composition of Formula (Ib) crystallized in a tetragonal phase. In additional times, the metal composition can have a bulk modulus that is similar to the bulk modulus of a metal composition of Formula (Ib) crystallized in a tetragonal phase.
In some instances, the metal composition has a hardness that is higher than the hardness of a metal composition of Formula (Ib) crystallized in a tetragonal phase. Other times, the metal composition can have a hardness that is lower than the hardness of a metal composition of Formula (Ib) crystallized in a tetragonal phase. In additional times, the metal composition can have a hardness that is similar to the hardness of a metal composition of Formula (Ib) crystallized in a tetragonal phase.
In some cases, the metal composition has at least one plane that exhibits a strain hardening effect when subjected to a pressure sufficient to induce strain hardening.
In some cases, at least one plane of the metal composition further exhibits a discontinuous increase in directional incompressibility.
In some instances, boron forms a chain within the structure of the metal composition of Formula (Ib) and is aligned along one axis of the structure. For example, the axis can be the c-axis or the a-axis. In some cases, the axis is the c-axis. In some cases, the axis is the a-axis.
In some instances, the chain of boron does not alternate to form a perpendicular array within the structure, as can be observed in the tetrahedral phase.
In some embodiments, N is Niobium (Nb) and the metal composition is a metal composition of Formula (Ic) crystallized in an orthorhombic phase,
W1-xNbxB Formula Ic
in which x has a value within the range 0.01 to 0.99, inclusively.
Sometimes, x can have a value within the range 0.05 to 0.95, 0.1 to 0.9, 0.1 to 0.6, 0.2 to 0.6, 0.3 to 0.6, 0.4 to 0.6, 0.2 to 0.55, 0.3 to 0.55, 0.4 to 0.55, 0.45 to 0.55, 0.1 to 0.5, 0.2 to 0.5, 0.3 to 0.5, 0.4 to 0.5, 0.5 to 0.55, or 0.45 to 0.5, inclusively. In some cases, x has a value within the range 0.1 to 0.9, inclusively. In some instances, x has a value within the range 0.1 to 0.6, 0.2 to 0.6, 0.3 to 0.6, or 0.4 to 0.6, inclusively. In some instances, x has a value within the range 0.2 to 0.55, 0.3 to 0.55, 0.4 to 0.55, or 0.45 to 0.55, inclusively. In additional instances, x has a value within the range 0.1 to 0.5, 0.2 to 0.5, 0.3 to 0.5, or 0.4 to 0.5, inclusively.
In some cases, x has a value of about 0.05, 0.1, 0.15, 0.2, 0.25, 0.3, 0.35, 0.4, 0.41, 0.42, 0.43, 0.44, 0.45, 0.46, 0.47, 0.48, 0.49, 0.5, 0.51, 0.52, 0.53, 0.54, 0.55, 0.56, 0.57, 0.58, 0.59, 0.6, 0.65, 0.7, 0.8, 0.9, or about 0.95. In some cases, x has a value of about 0.1. In some cases, x has a value of about 0.2. In some cases, x has a value of about 0.3. In some cases, x has a value of about 0.4. In some cases, x has a value of about 0.41. In some cases, x has a value of about 0.42. In some cases, x has a value of about 0.43. In some cases, x has a value of about 0.44. In some cases, x has a value of about 0.45. In some cases, x has a value of about 0.46. In some cases, x has a value of about 0.47. In some cases, x has a value of about 0.48. In some cases, x has a value of about 0.49. In some cases, x has a value of about 0.5. In some cases, x has a value of about 0.51. In some cases, x has a value of about 0.52. In some cases, x has a value of about 0.53. In some cases, x has a value of about 0.54. In some cases, x has a value of about 0.55. In some cases, x has a value of about 0.56. In some cases, x has a value of about 0.57. In some cases, x has a value of about 0.58. In some cases, x has a value of about 0.59. In some cases, x has a value of about 0.6. In some cases, x has a value of about 0.7. In some cases, x has a value of about 0.8. In some cases, x has a value of about 0.9.
Sometimes, the metal composition can have a bulk modulus that is higher than the bulk modulus of a metal composition of Formula (Ic) crystallized in a tetragonal phase. Other times, the metal composition can have a bulk modulus that is lower than the bulk modulus of a metal composition of Formula (Ic) crystallized in a tetragonal phase. In additional times, the metal composition can have a bulk modulus that is similar to the bulk modulus of a metal composition of Formula (Ic) crystallized in a tetragonal phase.
In some instances, the metal composition has a hardness that is higher than the hardness of a metal composition of Formula (Ic) crystallized in a tetragonal phase. Other times, the metal composition can have a hardness that is lower than the hardness of a metal composition of Formula (Ic) crystallized in a tetragonal phase. In additional times, the metal composition can have a hardness that is similar to the hardness of a metal composition of Formula (Ic) crystallized in a tetragonal phase.
In some cases, the metal composition has at least one plane that exhibits a strain hardening effect when subjected to a pressure sufficient to induce strain hardening.
In some cases, at least one plane of the metal composition further exhibits a discontinuous increase in directional incompressibility.
In some instances, boron forms a chain within the structure of the metal composition of Formula (Ic) and is aligned along one axis of the structure. For example, the axis can be the c-axis or the a-axis. In some cases, the axis is the c-axis. In some cases, the axis is the a-axis.
In some instances, the chain of boron does not alternate to form a perpendicular array within the structure, as can be observed in the tetrahedral phase.
In some embodiments, described herein include a metal composition of Formula (I):
W1-xNxB Formula I
wherein N is a non-radioactive Group V Transition Metal; and x has a value within the range 0.01 to 0.99, inclusively; and wherein the metal composition has at least one plane that exhibits a strain hardening effect when subjected to a pressure sufficient to induce strain hardening.
In some embodiments, N is selected from Tantalum (Ta), Vanadium (V), and Niobium (Nb). In some instances, N is Tantalum (Ta). In some cases, N is Vanadium (V). In other cases, N is Niobium (Nb).
Sometimes, x can have a value within the range 0.05 to 0.95, 0.1 to 0.9, 0.1 to 0.6, 0.2 to 0.6, 0.3 to 0.6, 0.4 to 0.6, 0.2 to 0.55, 0.3 to 0.55, 0.4 to 0.55, 0.45 to 0.55, 0.1 to 0.5, 0.2 to 0.5, 0.3 to 0.5, 0.4 to 0.5, 0.5 to 0.55, or 0.45 to 0.5, inclusively. In some cases, x has a value within the range 0.1 to 0.9, inclusively. In some instances, x has a value within the range 0.1 to 0.6, 0.2 to 0.6, 0.3 to 0.6, or 0.4 to 0.6, inclusively. In some instances, x has a value within the range 0.2 to 0.55, 0.3 to 0.55, 0.4 to 0.55, or 0.45 to 0.55, inclusively. In additional instances, x has a value within the range 0.1 to 0.5, 0.2 to 0.5, 0.3 to 0.5, or 0.4 to 0.5, inclusively.
In some cases, x has a value of about 0.05, 0.1, 0.15, 0.2, 0.25, 0.3, 0.35, 0.4, 0.41, 0.42, 0.43, 0.44, 0.45, 0.46, 0.47, 0.48, 0.49, 0.5, 0.51, 0.52, 0.53, 0.54, 0.55, 0.56, 0.57, 0.58, 0.59, 0.6, 0.65, 0.7, 0.8, 0.9, or about 0.95. In some cases, x has a value of about 0.1. In some cases, x has a value of about 0.2. In some cases, x has a value of about 0.3. In some cases, x has a value of about 0.4. In some cases, x has a value of about 0.41. In some cases, x has a value of about 0.42. In some cases, x has a value of about 0.43. In some cases, x has a value of about 0.44. In some cases, x has a value of about 0.45. In some cases, x has a value of about 0.46. In some cases, x has a value of about 0.47. In some cases, x has a value of about 0.48. In some cases, x has a value of about 0.49. In some cases, x has a value of about 0.5. In some cases, x has a value of about 0.51. In some cases, x has a value of about 0.52. In some cases, x has a value of about 0.53. In some cases, x has a value of about 0.54. In some cases, x has a value of about 0.55. In some cases, x has a value of about 0.56. In some cases, x has a value of about 0.57. In some cases, x has a value of about 0.58. In some cases, x has a value of about 0.59. In some cases, x has a value of about 0.6. In some cases, x has a value of about 0.7. In some cases, x has a value of about 0.8. In some cases, x has a value of about 0.9.
In some embodiments, a metal composition described herein is a metal composition of formula W0.5Ta0.5B in which the metal composition has at least one plane that exhibits a strain hardening effect when subjected to a pressure sufficient to induce strain hardening.
Sometimes, at least one plane of the metal composition can further exhibit a discontinuous increase in directional incompressibility.
In some instances, the metal composition is crystallized in an orthorhombic phase or a tetragonal phase. In some instances, the metal composition is crystallized in an orthorhombic phase. In other instances, the metal composition is crystallized in a tetragonal phase.
In some cases, the metal composition has a bulk modulus of from about 336 GPa to about 346 GPa.
In some cases, the metal composition has a hardness of about 33, about 34, about 35, about 36, about 37, or about 38 GPa.
Sometimes, boron can form a chain within the structure of the metal composition and is aligned along one axis of the structure. The axis can be the c-axis or the a-axis. Sometimes, boron can form a chain along the c-axis of the structure and the structure is in an orthorhombic phase. Sometimes, boron can form a chain along the a-axis of the structure and the structure is in an orthorhombic phase.
Sometimes, the chain of boron does not alternate to form a perpendicular array within the structure.
In some embodiments, described herein include a metal composition of Formula (I):
W1-xNxB Formula I
wherein N is a non-radioactive Group V Transition Metal; and x has a value within the range 0.01 to 0.99, inclusively; and boron forms a chain within the structure of the metal composition and is aligned along one axis of the structure.
In some embodiments, N is selected from Tantalum (Ta), Vanadium (V), and Niobium (Nb). In some instances, N is Tantalum (Ta). In some cases, N is Vanadium (V). In other cases, N is Niobium (Nb).
Sometimes, x can have a value within the range 0.05 to 0.95, 0.1 to 0.9, 0.1 to 0.6, 0.2 to 0.6, 0.3 to 0.6, 0.4 to 0.6, 0.2 to 0.55, 0.3 to 0.55, 0.4 to 0.55, 0.45 to 0.55, 0.1 to 0.5, 0.2 to 0.5, 0.3 to 0.5, 0.4 to 0.5, 0.5 to 0.55, or 0.45 to 0.5, inclusively. In some cases, x has a value within the range 0.1 to 0.9, inclusively. In some instances, x has a value within the range 0.1 to 0.6, 0.2 to 0.6, 0.3 to 0.6, or 0.4 to 0.6, inclusively. In some instances, x has a value within the range 0.2 to 0.55, 0.3 to 0.55, 0.4 to 0.55, or 0.45 to 0.55, inclusively. In additional instances, x has a value within the range 0.1 to 0.5, 0.2 to 0.5, 0.3 to 0.5, or 0.4 to 0.5, inclusively.
In some cases, x has a value of about 0.05, 0.1, 0.15, 0.2, 0.25, 0.3, 0.35, 0.4, 0.41, 0.42, 0.43, 0.44, 0.45, 0.46, 0.47, 0.48, 0.49, 0.5, 0.51, 0.52, 0.53, 0.54, 0.55, 0.56, 0.57, 0.58, 0.59, 0.6, 0.65, 0.7, 0.8, 0.9, or about 0.95. In some cases, x has a value of about 0.1. In some cases, x has a value of about 0.2. In some cases, x has a value of about 0.3. In some cases, x has a value of about 0.4. In some cases, x has a value of about 0.41. In some cases, x has a value of about 0.42. In some cases, x has a value of about 0.43. In some cases, x has a value of about 0.44. In some cases, x has a value of about 0.45. In some cases, x has a value of about 0.46. In some cases, x has a value of about 0.47. In some cases, x has a value of about 0.48. In some cases, x has a value of about 0.49. In some cases, x has a value of about 0.5. In some cases, x has a value of about 0.51. In some cases, x has a value of about 0.52. In some cases, x has a value of about 0.53. In some cases, x has a value of about 0.54. In some cases, x has a value of about 0.55. In some cases, x has a value of about 0.56. In some cases, x has a value of about 0.57. In some cases, x has a value of about 0.58. In some cases, x has a value of about 0.59. In some cases, x has a value of about 0.6. In some cases, x has a value of about 0.7. In some cases, x has a value of about 0.8. In some cases, x has a value of about 0.9.
In some embodiments, a metal composition described herein is a metal composition of formula W0.5Ta0.5B in which boron forms a chain within the structure of the metal composition and is aligned along one axis of the structure.
In some instances, the metal composition is crystallized in an orthorhombic phase or a tetragonal phase. In some instances, the metal composition is crystallized in an orthorhombic phase. In other instances, the metal composition is crystallized in a tetragonal phase.
In some cases, the metal composition has a bulk modulus of from about 336 GPa to about 346 GPa.
In some cases, the metal composition has a hardness of about 33, about 34, about 35, about 36, about 37, or about 38 GPa.
In some instances, the metal composition has at least one plane that exhibits a strain hardening effect when subjected to a pressure sufficient to induce strain hardening. Sometimes, at least one plane of the metal composition can further exhibit a discontinuous increase in directional incompressibility.
Sometimes, the axis can be the c-axis or the a-axis. Sometimes, boron can form a chain along the c-axis of the structure and the structure is in an orthorhombic phase. Sometimes, boron can form a chain along the a-axis of the structure and the structure is in an orthorhombic phase.
Sometimes, the chain of boron does not alternate to form a perpendicular array within the structure.
Methods of Use
In certain embodiments, described herein include methods of making metal compositions and methods of using the same. In some embodiments, described herein is a method of making a stable metal composition comprising: (a) introducing a plurality of additive particles into the interstices of a metal composition precursor to form a metal composition, wherein the plurality of additive particles is selected from vanadium, niobium, and tantalum; and (b) subjecting the metal composition to a temperature and pressure at which the metal composition is stable at room temperature.
In some embodiments, the metal composition precursor comprises a tungsten and boron molecule of formula WB.
In some embodiments, the subjecting further comprises sintering the metal composition precursor with the additive particles to form the stable metal composition. Sintering is the process of compacting and forming a solid mass of a material by heating and/or pressure without liquefaction.
In some embodiments, the stable metal composition has the formula W1-xNxB, wherein N is an additive particle selected from vanadium, niobium, and tantalum and x has a value within the range 0.01 to 0.99, inclusively. In some instances, N is Tantalum (Ta). In some cases, N is Vanadium (V). In other cases, N is Niobium (Nb).
Sometimes, x can have a value within the range 0.05 to 0.95, 0.1 to 0.9, 0.1 to 0.6, 0.2 to 0.6, 0.3 to 0.6, 0.4 to 0.6, 0.2 to 0.55, 0.3 to 0.55, 0.4 to 0.55, 0.45 to 0.55, 0.1 to 0.5, 0.2 to 0.5, 0.3 to 0.5, 0.4 to 0.5, 0.5 to 0.55, or 0.45 to 0.5, inclusively. In some cases, x has a value within the range 0.1 to 0.9, inclusively. In some instances, x has a value within the range 0.1 to 0.6, 0.2 to 0.6, 0.3 to 0.6, or 0.4 to 0.6, inclusively. In some instances, x has a value within the range 0.2 to 0.55, 0.3 to 0.55, 0.4 to 0.55, or 0.45 to 0.55, inclusively. In additional instances, x has a value within the range 0.1 to 0.5, 0.2 to 0.5, 0.3 to 0.5, or 0.4 to 0.5, inclusively.
In some cases, x has a value of about 0.05, 0.1, 0.15, 0.2, 0.25, 0.3, 0.35, 0.4, 0.41, 0.42, 0.43, 0.44, 0.45, 0.46, 0.47, 0.48, 0.49, 0.5, 0.51, 0.52, 0.53, 0.54, 0.55, 0.56, 0.57, 0.58, 0.59, 0.6, 0.65, 0.7, 0.8, 0.9, or about 0.95. In some cases, x has a value of about 0.1. In some cases, x has a value of about 0.2. In some cases, x has a value of about 0.3. In some cases, x has a value of about 0.4. In some cases, x has a value of about 0.41. In some cases, x has a value of about 0.42. In some cases, x has a value of about 0.43. In some cases, x has a value of about 0.44. In some cases, x has a value of about 0.45. In some cases, x has a value of about 0.46. In some cases, x has a value of about 0.47. In some cases, x has a value of about 0.48. In some cases, x has a value of about 0.49. In some cases, x has a value of about 0.5. In some cases, x has a value of about 0.51. In some cases, x has a value of about 0.52. In some cases, x has a value of about 0.53. In some cases, x has a value of about 0.54. In some cases, x has a value of about 0.55. In some cases, x has a value of about 0.56. In some cases, x has a value of about 0.57. In some cases, x has a value of about 0.58. In some cases, x has a value of about 0.59. In some cases, x has a value of about 0.6. In some cases, x has a value of about 0.7. In some cases, x has a value of about 0.8. In some cases, x has a value of about 0.9.
In some embodiments, a metal composition described herein is a metal composition of formula W0.5Ta0.5B.
In some instances, the stable metal composition is crystallized in an orthorhombic phase or a tetragonal phase. In some instances, the stable metal composition is crystallized in an orthorhombic phase. In other instances, the stable metal composition is crystallized in a tetragonal phase.
In some cases, the stable metal composition has a bulk modulus of from about 336 GPa to about 346 GPa.
In some cases, the stable metal composition has a hardness of about 33, about 34, about 35, about 36, about 37, or about 38 GPa.
In some instances, the stable metal composition has at least one plane that exhibits a strain hardening effect when subjected to a pressure sufficient to induce strain hardening. Sometimes, at least one plane of the stable metal composition can further exhibit a discontinuous increase in directional incompressibility.
Sometimes, boron can form a chain within the structure of the stable metal composition and is aligned along one axis of the structure. The axis can be the c-axis or the a-axis. Sometimes, boron can form a chain along the c-axis of the structure and the structure is in an orthorhombic phase. Sometimes, boron can form a chain along the a-axis of the structure and the structure is in an orthorhombic phase.
Sometimes, the chain of boron does not alternate to form a perpendicular array within the structure.
In some cases, the stable metal composition is an entropically stable metal composition.
In some embodiments, described herein include a method of making a tool, comprising: (a) providing a powder comprising a plurality of metal composition particles, wherein the plurality of metal composition particles comprise metal compositions described herein; and (b) compressing said powder to form a self-supporting structure. In some embodiments, the metal composition has the formula W1-xNxB, wherein N is selected from vanadium, niobium, and tantalum and x has a value within the range 0.01 to 0.99, inclusively. In some instances, N is Tantalum (Ta). In some cases, N is Vanadium (V). In other cases, N is Niobium (Nb).
Sometimes, x can have a value within the range 0.05 to 0.95, 0.1 to 0.9, 0.1 to 0.6, 0.2 to 0.6, 0.3 to 0.6, 0.4 to 0.6, 0.2 to 0.55, 0.3 to 0.55, 0.4 to 0.55, 0.45 to 0.55, 0.1 to 0.5, 0.2 to 0.5, 0.3 to 0.5, 0.4 to 0.5, 0.5 to 0.55, or 0.45 to 0.5, inclusively. In some cases, x has a value within the range 0.1 to 0.9, inclusively. In some instances, x has a value within the range 0.1 to 0.6, 0.2 to 0.6, 0.3 to 0.6, or 0.4 to 0.6, inclusively. In some instances, x has a value within the range 0.2 to 0.55, 0.3 to 0.55, 0.4 to 0.55, or 0.45 to 0.55, inclusively. In additional instances, x has a value within the range 0.1 to 0.5, 0.2 to 0.5, 0.3 to 0.5, or 0.4 to 0.5, inclusively.
In some cases, x has a value of about 0.05, 0.1, 0.15, 0.2, 0.25, 0.3, 0.35, 0.4, 0.41, 0.42, 0.43, 0.44, 0.45, 0.46, 0.47, 0.48, 0.49, 0.5, 0.51, 0.52, 0.53, 0.54, 0.55, 0.56, 0.57, 0.58, 0.59, 0.6, 0.65, 0.7, 0.8, 0.9, or about 0.95. In some cases, x has a value of about 0.1. In some cases, x has a value of about 0.2. In some cases, x has a value of about 0.3. In some cases, x has a value of about 0.4. In some cases, x has a value of about 0.41. In some cases, x has a value of about 0.42. In some cases, x has a value of about 0.43. In some cases, x has a value of about 0.44. In some cases, x has a value of about 0.45. In some cases, x has a value of about 0.46. In some cases, x has a value of about 0.47. In some cases, x has a value of about 0.48. In some cases, x has a value of about 0.49. In some cases, x has a value of about 0.5. In some cases, x has a value of about 0.51. In some cases, x has a value of about 0.52. In some cases, x has a value of about 0.53. In some cases, x has a value of about 0.54. In some cases, x has a value of about 0.55. In some cases, x has a value of about 0.56. In some cases, x has a value of about 0.57. In some cases, x has a value of about 0.58. In some cases, x has a value of about 0.59. In some cases, x has a value of about 0.6. In some cases, x has a value of about 0.7. In some cases, x has a value of about 0.8. In some cases, x has a value of about 0.9.
In some embodiments, also included herein are tools and abrasive materials that comprise a metal composition described herein. In some instances, described herein include a tool which comprise a surface for cutting or abrading, said surface being a surface of a metal composition described herein. In some embodiments, the metal composition has the formula W1-xNxB, wherein N is selected from vanadium, niobium, and tantalum and x has a value within the range 0.01 to 0.99, inclusively. In some instances, N is Tantalum (Ta). In some cases, N is Vanadium (V). In other cases, N is Niobium (Nb).
Sometimes, x can have a value within the range 0.05 to 0.95, 0.1 to 0.9, 0.1 to 0.6, 0.2 to 0.6, 0.3 to 0.6, 0.4 to 0.6, 0.2 to 0.55, 0.3 to 0.55, 0.4 to 0.55, 0.45 to 0.55, 0.1 to 0.5, 0.2 to 0.5, 0.3 to 0.5, 0.4 to 0.5, 0.5 to 0.55, or 0.45 to 0.5, inclusively. In some cases, x has a value within the range 0.1 to 0.9, inclusively. In some instances, x has a value within the range 0.1 to 0.6, 0.2 to 0.6, 0.3 to 0.6, or 0.4 to 0.6, inclusively. In some instances, x has a value within the range 0.2 to 0.55, 0.3 to 0.55, 0.4 to 0.55, or 0.45 to 0.55, inclusively. In additional instances, x has a value within the range 0.1 to 0.5, 0.2 to 0.5, 0.3 to 0.5, or 0.4 to 0.5, inclusively.
In some cases, x has a value of about 0.05, 0.1, 0.15, 0.2, 0.25, 0.3, 0.35, 0.4, 0.41, 0.42, 0.43, 0.44, 0.45, 0.46, 0.47, 0.48, 0.49, 0.5, 0.51, 0.52, 0.53, 0.54, 0.55, 0.56, 0.57, 0.58, 0.59, 0.6, 0.65, 0.7, 0.8, 0.9, or about 0.95. In some cases, x has a value of about 0.1. In some cases, x has a value of about 0.2. In some cases, x has a value of about 0.3. In some cases, x has a value of about 0.4. In some cases, x has a value of about 0.41. In some cases, x has a value of about 0.42. In some cases, x has a value of about 0.43. In some cases, x has a value of about 0.44. In some cases, x has a value of about 0.45. In some cases, x has a value of about 0.46. In some cases, x has a value of about 0.47. In some cases, x has a value of about 0.48. In some cases, x has a value of about 0.49. In some cases, x has a value of about 0.5. In some cases, x has a value of about 0.51. In some cases, x has a value of about 0.52. In some cases, x has a value of about 0.53. In some cases, x has a value of about 0.54. In some cases, x has a value of about 0.55. In some cases, x has a value of about 0.56. In some cases, x has a value of about 0.57. In some cases, x has a value of about 0.58. In some cases, x has a value of about 0.59. In some cases, x has a value of about 0.6. In some cases, x has a value of about 0.7. In some cases, x has a value of about 0.8. In some cases, x has a value of about 0.9.
In additional embodiments, further described herein include abrasive materials that comprise a plurality of abrasive particles, each being a metal composition described herein. In some embodiments, the metal composition has the formula W1-xNxB, wherein N is selected from vanadium, niobium, and tantalum and x has a value within the range 0.01 to 0.99, inclusively. In some instances, N is Tantalum (Ta). In some cases, N is Vanadium (V). In other cases, N is Niobium (Nb).
Sometimes, x can have a value within the range 0.05 to 0.95, 0.1 to 0.9, 0.1 to 0.6, 0.2 to 0.6, 0.3 to 0.6, 0.4 to 0.6, 0.2 to 0.55, 0.3 to 0.55, 0.4 to 0.55, 0.45 to 0.55, 0.1 to 0.5, 0.2 to 0.5, 0.3 to 0.5, 0.4 to 0.5, 0.5 to 0.55, or 0.45 to 0.5, inclusively. In some cases, x has a value within the range 0.1 to 0.9, inclusively. In some instances, x has a value within the range 0.1 to 0.6, 0.2 to 0.6, 0.3 to 0.6, or 0.4 to 0.6, inclusively. In some instances, x has a value within the range 0.2 to 0.55, 0.3 to 0.55, 0.4 to 0.55, or 0.45 to 0.55, inclusively. In additional instances, x has a value within the range 0.1 to 0.5, 0.2 to 0.5, 0.3 to 0.5, or 0.4 to 0.5, inclusively.
In some cases, x has a value of about 0.05, 0.1, 0.15, 0.2, 0.25, 0.3, 0.35, 0.4, 0.41, 0.42, 0.43, 0.44, 0.45, 0.46, 0.47, 0.48, 0.49, 0.5, 0.51, 0.52, 0.53, 0.54, 0.55, 0.56, 0.57, 0.58, 0.59, 0.6, 0.65, 0.7, 0.8, 0.9, or about 0.95. In some cases, x has a value of about 0.1. In some cases, x has a value of about 0.2. In some cases, x has a value of about 0.3. In some cases, x has a value of about 0.4. In some cases, x has a value of about 0.41. In some cases, x has a value of about 0.42. In some cases, x has a value of about 0.43. In some cases, x has a value of about 0.44. In some cases, x has a value of about 0.45. In some cases, x has a value of about 0.46. In some cases, x has a value of about 0.47. In some cases, x has a value of about 0.48. In some cases, x has a value of about 0.49. In some cases, x has a value of about 0.5. In some cases, x has a value of about 0.51. In some cases, x has a value of about 0.52. In some cases, x has a value of about 0.53. In some cases, x has a value of about 0.54. In some cases, x has a value of about 0.55. In some cases, x has a value of about 0.56. In some cases, x has a value of about 0.57. In some cases, x has a value of about 0.58. In some cases, x has a value of about 0.59. In some cases, x has a value of about 0.6. In some cases, x has a value of about 0.7. In some cases, x has a value of about 0.8. In some cases, x has a value of about 0.9.
Unless otherwise defined, all technical terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. It is to be understood that the general description and the detailed description are exemplary and explanatory only and are not restrictive of any subject matter claimed. As used in this specification, the singular forms “a,” “an,” and “the” include plural references unless the context clearly dictates otherwise. Any reference to “or” herein is intended to encompass “and/or” unless otherwise stated.
As used herein, ranges and amounts can be expressed as “about” a particular value or range. About also includes the exact amount. Hence “about 5 GPa” means “about 5 GPa” and also “5 GPa.” Generally, the term “about” includes an amount that would be expected to be within experimental error.
The section headings used herein are for organizational purposes only and are not to be construed as limiting the subject matter described.
These examples are provided for illustrative purposes only and not to limit the scope of the claims provided herein.
In some embodiments, the composition for a metal alloy, the tool for cutting or abrading, the abrasive material, and the method of making and using the same as described herein include experimental procedures to test the hardness of a material, including indent diagonals, radial diffraction, differential strain, thermal stability, among others.
Tungsten (Strem, 99.95%), tantalum (Roc/Ric, 99.9%), and boron (Materion, 99%) powders were stochiometrically ground in an agate mortar and pestle (typical total loadings were 1 gram). Some samples had a slight excess of boron due to boron sublimation from the high temperatures of arcing. The homogeneous powders were pressed into a pellet, arced, turned over, and re-arced to ensure homogeneity. Samples were arced under high-purity argon under ambient pressure. The ingots were then bisected, with one half crushed for powder X-ray diffraction, high pressure radial diffraction, and thermal gravimetric analysis. The other half was mounted in epoxy and polished, for hardness and scanning electron microscopy (SEM), and for phase analysis. Mounted samples were polished with a SouthBay Technologies Polishing Station using polishing papers from 120 to 1200 grit (Allied High Tech Products Inc.).
Samples were analyzed by powder X-ray diffraction on a Panalytical X'Pert diffractometer using a Cu kα1 source (λ=1.5418 Å). The as-collected spectra were compared against JCPDS Card #00-006-0541 using X'Pert HighScore Plus as the processing software. Powder samples were then refined by size using a solvent suspension method, and imaged under a TF-20 transmission electron microscope (TEM) for size analysis. Size-refined powders were then used for high pressure radial diffraction.
Polished samples were imaged under backscatter SEM using a Nova 230 electron microscope with electron dispersive spectroscopy (EDS) used to determine homogeneity. Polished samples were measured for hardness on a Micromet 2103 equipped with a pyramid diamond indenter tip. With a dwell time of 15 s, the samples were indented under loads of 0.49, 0.98, 1.96, 2.9, and 4.9 N. Indent diagonals were measured using a Zeiss Axiotech 100HD optical microscope (Carl Zeiss Vision GmbH, Germany). Vickers hardness is determined from Equation 1.1 using the arithmetic mean of H randomly chosen indents:
where P is the applied load and d is the average of the diagonals.
Radial diffraction was performed at the Advanced Light Source at Lawrence Berkeley National Labs using a diamond anvil cell (DAC). Incompressibility was determined using the third-order finite strain Birch-Murnaghan equation of state (Equation 1.2):
where P is the applied load, K0 is the bulk modulus, V is the deformed unit cell volume, V0 is the undeformed unit cell volume, and K0′ is the derivative of the K0 with respect to P. Here, K0′ is fixed to 4.
Differential strain was interpreted using lattice strain theory from the high-pressure radial diffraction using Equation 1.3:
d
meas(hkl)=dhydro(hkl)[1+(1−3 cos2 Ψ)]Q(hkl) [1.3]
where Ψ is the angle between the diffracting plane normal and the maximum stress axis, dhydro(hkl) is the hydrostatic d-spacing (measured when Ψ=54.7°), and dmeas(hkl) is the measured d-spacing under pressure. Q(hkl), the orientation dependent differential strain, can be written as:
where G is the aggregate shear strain, and t is the differential stress (18). The differential stress, t, can be rewritten using the Tresca yield criterion,
t=σ
axial,max−σradial,min≤2τ=σy [1.5]
where σaxial, max is the maximum stress along the axial direction, σradial, min is the minimum stress along the radial direction, and σy is the yield strength. The elastically-supported differential stress, t, enables one to estimate the lower-bound of the material's yield strength, σy.
Thermal stability in air of the materials is determined using a Pyris Diamond thermogravimetric/differential thermal analyzer. Powder samples were heated in air up to 200° C. at a rate of 20° C./min, held for 20 min to remove residual moisture, and then heated up to 1000° C. at a rate of 2° C./min.
Tungsten monoboride crystallizes in either a low temperature tetragonal or a high temperature orthorhombic unit cell. The primary difference between these two phases is found in the layer of boron chains, where in the tetragonal (low temperature) form, the boron chains alternate orthogonally, while in the orthorhombic (high temperature) form the boron chains are all aligned along the a-axis. Similarly, both structures possess a bilayer of tungsten atoms as can be seen in
Inspection of the tungsten monoboride unit cell has shown that it possesses a bilayer of tungsten atoms separated by boron chains. Because tungsten monoboride (unlike tungsten tetraboride, WB4) is a lower boride, it should not possess a substantial degree of covalent bonding which can prevent the formation or movement of dislocations. Combined with the W—W bond lengths approaching that of tungsten metal, it infers that the majority of the materials strength is supported in this system through the metal atoms, and thus, the hardness of tungsten monoboride is determined by its metallic bonding. If dislocations can be prevented in this metallic plane, it should increase the overall hardness of tungsten monoboride.
Therefore, solid-solution strengthening is a real possibility. By substituting tungsten with larger atoms, the slipping of the metallic planes can be prevented through dislocation pinning, and with the higher resistance to dislocations, the overall hardness should increase. As such, the subject matter described herein, in certain embodiments, substitutes tantalum onto the tungsten sites because tantalum has a similar valence, electronegativity, and atomic radii when compared to tungsten. Furthermore, tantalum monoboride crystallizes into the same phase as the high temperature form of tungsten monoboride, which satisfies the Hume-Rothery rules for solid solutions. It should be noted that the end members of W1-xTaxB are not known to be superhard, and as such this is an excellent system to study.
Tantalum monoboride crystallizes in an orthogonal unit cell, and when combined with the fast cooling rate of the copper hearth of the arc melter, it is expected that all W1-xTaxB compositions (where x=0.01 to 0.5) will crystallize in the orthorhombic phase. Indeed, powder X-ray diffraction suggest that even at 1% Ta concentration, as seen in W0.99Ta0.01B, the favored phase is the high temperature orthorhombic modification. Moreover, TaB is miscible in WB at high concentrations with no secondary phases as observed by powder X-ray diffraction (
There is a noticeable shift towards larger lattice parameters with increased tantalum concentration, and this is expected because tantalum (1.343 Å) has a slightly larger atomic radius when compared to tungsten (1.299 Å). As shown in
This suggests a well-behaved alloy system with tantalum randomly distributed across the tungsten sites. Backscatter scanning electron microscopy confirms that there are no secondary phases, and elemental mapping with electron dispersive spectroscopy (EDS) suggests that both tantalum and tungsten are well dispersed (
Vickers hardness was then measured under loads of 0.49, 0.98, 1.96, 2.9, and 4.9 N (
This linear hardness trend that peaks at a 50% concentration is quite unusual amongst the borides. For example, WB4 forms solid solutions with tantalum, chromium, and manganese, but the hardness trend for WB4 solid solutions is not linear. Likewise, the hardness of Os1-xRuxB2 solid solutions is linear, but it does not peak at 50% concentration. Such a unique correlation in W1-xTaxB, combined with inspection of the orthorhombic crystal structure, suggests that the metallic bilayer is responsible for the material's strength. By substituting tungsten with larger tantalum atoms, plane slipping will be diminished through dislocation pinning. At 50% concentration, pinning will be maximized, and this is reflected in the hardness measurements. This chemical tuning of the structure shows that the hardness of tungsten monoboride can be increased through solid solution hardening.
To confirm the hardening effects of substituting tantalum into the metallic bilayer, high-pressure diffraction studies are used to correlate macroscopic hardness with microscopic deformations. By compressing samples under non-hydrostatic stress in a high-pressure diamond anvil cell, conditions similar to those found under the indenter tip can be controllably produced in a geometry that can be readily probed using X-ray diffraction. Such experiments can provide a lattice specific measure of yield strength and the predominant slip systems available in the material. High-pressure radial diffraction is a well-known technique that has been satisfactorily used previously to determine the amount of load each plane supports in nanocrystalline WB.
Here, high-pressure radial diffraction is used to determine which planes in tungsten monoboride are responsible for the superhardness. This enables an understanding of the slip system in the material. Planes that have a low differential strain (t/G) value tend to dislocate and slip, while planes that have a high t/G value can support greater force and pressure. For W0.99Ta0.01B, the planes (200), (020), and (002) were chosen for study because they represent the anisotropy of the unit cell. Dislocations in the (200) cut between the boron-boron chains, while the (020) cut through the tungsten bilayer, and the (002) cuts through the boron-boron bonds (
In a particular embodiment, a differential strain plot of a W(1-x) Tax B metal alloy is shown in
More intriguingly, the behavior of the (020) plane reveals key insights into the nature of the bonding. As can be seen in
In a particular embodiment, deformation performance of a W(1-x) Tax B metal alloy indicates that the deformation in the unit cell volume is fitted to a Third-order Birch-Murnaghan equation of state, as shown in
Oxidation resistance was measured using thermal gravimetric analysis. In practical applications, high oxidation resistance is needed because the act of machining generates high temperatures from friction. In a particular embodiment, thermogravimetric analysis (TGA) of W0.5 Ta0.5B suggests that the oxidation of W0.5Ta0.5B begins at 550° C. in air, as shown in
The greatly increased role of metallic bonding in the hardness of WB offers an intriguing line of inquiry into superhard materials. Typically, non-directional metallic bonds are prone to slipping and thus, conventional wisdom would suggest that the best way to make a superhard metal would be to add boron until covalent bonding dominates and prevents dislocations from motion. As such, superhardness should generally be found in strongly covalent materials such as diamond or tungsten tetraboride. In a particular embodiment, resistance/temperature relationship of a W(1-x) Tax B metal alloy indicates that the electrical resistance of the ingot increases with temperature, which suggests that W0.5Ta0.5B is metallic, as shown in
Volumetric Deformation and Strength Anisotropy of Orthorhombic Tungsten Monoboride Under Non-Hydrostatic Compression
As the world's hardest natural material, diamond has limited applications in cutting and drilling since it reacts with ferrous materials to form brittle carbides. Alternative superhard materials such as rhenium diboride (ReB2) and cubic boron nitride (c-BN) both have hardness values close to that of diamond and are chemically stable relative to diamond. However, the stringent manufacturing requirements and/or expensive raw materials lead to high manufacturing costs. In some instances, tungsten tetraboride (WB4) is a less expensive superhard material. WB4 has a Vickers hardness that reaches 43.3±2.9 GPa under an applied load of 0.49 N and a bulk modulus of 324±3 GPa. Its hardness results from the high valence electron density of tungsten and short strong covalent bonds introduced by boron. In some instances, pure WB4 is thermodynamically unfavorable, and WB4 samples prepared by an arc melting process have a W:B molar ratio of about 1:12, which is a composite of WB4 and crystalline boron, and thereby introduces non-uniformity within the structure. In some cases, lower borides of transition metals are studied.
Orthorhombic WB and tetragonal WB were synthesized by arc melting. Tungsten powder and boron powder with a 1:1 molar ratio were mixed together followed by pressing into pellets. Subsequently, the pellets were arc melted and cooled in argon gas. In order to stabilize the HT-orthorhombic phase of WB at room temperature, 5 at. % Ta was added because TaB is known to crystallize in an orthorhombic structure. Tetragonal WB and orthorhombic stabilized WB pellets were then crushed and ground to powder respectively with a particle size of <20 μm. Non-hydrostatic in situ high pressure angle-dispersive X-ray diffraction experiments were performed to characterize the strength and deformation behavior at synchrotron beamline 12.2.2 of the Advanced Light Source (ALS, Lawrence Berkeley National Lab). A prepared polycrystalline WB sample was loaded into a laser drilled hole (˜60 μm in diameter) in a boron gasket (˜400 μm in diameter and ˜70 μm in thickness). A small circle of Pt foil (˜15 μm in diameter) was placed on top of the sample to serve as a pressure internal standard. No pressure-transmitting medium was used in order to create a non-hydrostatic environment in the DAC. A monochromatic X-ray beam with a wavelength of 0.4959 Å, and size of 20×20 μm was passed through the sample perpendicular to the loading axis. The 2D diffraction image was collected with program FIT2D (Hammersley, et al., High Pressure Research 14, 235 (1996)) at a step of ˜4 GPa after calibration of the detector distance and orientation using a LaB6 standard. The combination of radial X-ray diffraction and lattice strain theory enabled studying of the stress state of samples under non-hydrostatic compression in a DAC.
The stress state in a compressed sample under uniaxial loading in a DAC is characterized by σ3, the maximum stress along the axial direction, and σ1, the minimum stress in the radial direction. The difference between σ1 and σ3 is the macroscopic differential stress t, which can be defined by the Tresca yield criterion:
t=σ
3−σ1≤2τ=σy, [2.1]
where τ is the shear strength and σy is the yield strength of the material (Ruoff, A. L. J. Appl. Phys. 46, 1389 (1975)). A measurement of the elastically-supported differential stress enables one to estimate the lower-bound of the material's yield strength, σy. According to lattice strain theory, the measured d-spacing, dm(hkl) is a function of dp(hkl), d-spacing under the hydrostatic pressure, and φ, angle between the diffracting plane normal and the maximum stress axis,
d
m(hkl)=dp(hkl)[1+(1−3 cos2φ)Q(hkl)], [2.])
where Q (hkl) is the orientation dependent lattice strain (Singh, A. K. J. Appl. Phys. 106, 043514 (2009)), which is defined by
Here GR (hkl) is the lattice dependent Reuss shear modulus under an iso-stress condition while the Voigt shear modulus, GV, is independent of hkl under iso-strain condition. The GV is given by
15GV=(c11+c22+c33)−(c12+c23+c31)+3(c44+c55+c66) [2.4]
For orthorhombic and tetragonal systems, the expressions of GR(hkl) in terms of elastic compliance, [Sij] can be found in Singh, et al., J. Appl. Phys. 83, 7567 (1998). The actual shear modulus of a randomly oriented polycrystalline sample is neither GR (hkl) nor GV, but a weighted average of them. Approximately, the differential stress can be given by
t=6G<Q(hkl)>, [2.5]
where <Q (hkl)> stands for the average value of lattice strain observed for the diffraction peaks and G is the aggregate shear modulus. According to Equation 2.2, one could find that dm(hkl) is a linear function of (1−3 cos2φ) with a slope of dp(hkl)Q(hkl) and an intercept of dp(hkl) (at φ=54.7°). The Q(hkl) resolved from the slope can be used to evaluate and describe contributions of both plastic and elastic deformation. While the pressure dependent d-spacing at φ=54.7° reflects the compression behavior due to hydrostatic component of stress, namely, the equivalent hydrostatic compression curve can be derived from non-hydrostatic data. The zero pressure bulk modulus, K0, can be determined by fitting the compression curve to the Birch-Murnaghan equation-of-state (EOS),
P=1.5K0[(V/V0)−7/3−(V/V0)−5/3]. [2.6]
Here, the pressure, P, and the unit cell volume, V, is measured at φ=54.7°.
The bulk modulus was calculated by isotopically scaling the unit cell by small increments. The external pressure and volume were extracted from the calculation and then fit to a polynomial, the linear coefficient of this polynomial is the calculated Bulk Modulus. The experimental unit cells were used for this calculation. Dispersion interactions were approximated using the D2 Grimme scheme. PAW PBE basis sets and pseudopotentials applied to all atoms. All calculations carried out using the PBE/PBE functional in VASP except for the energy differences, which used the RPBE functional (Adamo, C., and Barone, V. J. Chem. Phys. 110, 6158 (1999); Hafner, J. Comput. Chem. 29, 2044 (2008)). The HT phase was calculated with a 24×8×24 k-mesh to assess the dependence on k-point density, results were found to be consistent with a smaller k-mesh of 6×2×6. DOS and Band calculations were performed with the 24×8×24 mesh while the shearing calculations used the 6×2×6 mesh. (Shearing removes symmetry making larger meshes less feasible). An energy cutoff of 320 eV was used.
The stress testing of electronic states procedure was developed in-house and has been demonstrated to characterize the strength of bonds along different distortions. The Bloch state visualizations were generated with quantum espresso. Using the PBE/PBE functional, and using a PBE scalar relativistic corrected basis for B, and the ultra soft scalar relativistic corrected basis for W. Once again, the cutoff energy was set to 320 eV. The isosurfaces had isovalues of ±0.005. The cluster models were run in Gaussian 09 using PBEPBE and the lanl2dz basis set.
HT-Orthorhombic WB Exhibits Different Properties than LT-Tetragonal WB
In some instances, tungsten monoboride possesses two distinct phases with a B:W molar ratio of 1:1, an orthorhombic high temperature (HT) and tetragonal low temperature (LT) phase with a phase transition temperature of 2170° C. Both of these phases share the same alternating BCC tungsten bilayer/boron chain superstructure, but differ in the arrangement of the borons. In the LT-tetragonal phase, the boron chains alternate to form perpendicular arrays (
In some instances, additional properties such as elastic deformation behavior, e.g., bulk modulus and crystal lattice strain response to a large applied non-hydrostatic stress and phase differences are further studied herein.
Synchrotron-based angle dispersive X-ray diffraction (XRD) experiments in radial geometry using a diamond anvil cell (DAC) were performed to examine the volumetric deformations and anisotropic lattice deformations of orthorhombic and tetragonal WB under applied pressures up to 52 GPa and 36 GPa respectively. The diffraction patterns were collected at steps of ˜4 GPa and analyzed using lattice strain theory (Singh et al, Phys. Rev. Lett. 80, 2157 (1998); Singh, J. Appl. Phys. 73, 4278 (1993); and Singh, et al, J. Appl. Phys. 83, 7567 (1998)). In the radial experimental geometry, the anisotropic stress condition in a DAC during compression is similar to that under an indenter's tip in a microindentation hardness test. In such cases, it provides insights for understanding the microscopic response of a crystal lattice to differential stress and the macroscopic response to applied loads. Additionally, radial XRD enables in situ observations of deformation behavior in a lattice specific manner as a function of pressure.
Representative XRD patterns for HT-orthorhombic WB are shown in
The pressure dependence of d-spacings and lattice constants is summarized in
For HT-orthorhombic WB, the t(200)/G ratio shows an almost linear variation with pressure achieving the highest value of 4.7% at 52 GPa. This suggests that along the [200] direction/a-axis, the HT-orthorhombic WB phase can support a higher differential stress than the other directions. The t(020)/G ratio increases linearly with pressure at the beginning, but then levels off and increases more slowly above ˜15 GPa, ending with a plateau value of 4.4% at ˜26 GPa. The plateau is an indication of the onset of plastic deformation by a slip system. As shown in
Unlike the differential strain, the differential stress (t) can be correlated to hardness. The differential stress under Reuss (Reuss, A, Angew. Z., Math. Mech. 9, 49 (1929)) and Voigt (Voigt, W. Lehrbuch der Kristallphysik (Teubner, Leipzig, 1928)) conditions for HT-orthorhombic WB and LT-tetragonal WB was calculated by using the elastic stiffness constants provided by Liang, et al., Comput. Mater. Sci. 68, 222 (2013) and Cheng, et al., Act. Crystallogr. 70, 85 (2014), respectively. As shown in
In order to confirm the anisotropy in strength, the DFT energy shifts in response to small shearing distortions were calculated. As shown in
To estimate the macroscopic differential stress (t) for polycrystalline sample, the contribution from each diffraction plane is considered. For example, t was obtained by taking the average of t(200)/G, t(020)/G and t(002)/G followed by multiplying to theoretical shear modulus of 198 GPa. Similarly, the differential stress of LT-tetragonal WB was obtained by using the shear modulus of 199 GPa. The shear modulus at high pressure were extrapolated using dG/dP=1.5. The hardness test shows that HT-orthorhombic WB and LT-tetragonal WB are comparable in hardness. As seen in
Note that although the LT-tetragonal and HT-orthorhombic phases show similar maximum differential stresses, they present different slopes. This may result from the difference in incompressibility between the two structures. The unit cell volume of HT-orthorhombic WB at elevated pressures ranging from 1.7 GPa to 52 GPa is shown in
In addition to the volume deformation behavior, the lattice incompressibility was also examined. The fractional lattice constants of HT WB present a discontinuous change as can be seen in
The high pressure behavior of WB in two different phases was compared using synchrotron based X-ray diffraction under non-hydrostatic compression up to ˜52 and ˜36 GPa, respectively. The bulk modulus for each phase was determined and the LT-tetragonal phase was found to be more incompressible than the HT-orthorhombic phase. Moreover, a discontinuous change in directional compressibility in HT-orthorhombic WB was observed. Although the two phases show similar harnesses, they present a distinct anisotropic nature in strength. The peak profile and lattice strain was examined, showing that the (200) is likely the strongest plane that supports the highest differential stress over other selected planes. The (020) was found to start slipping at ˜15 GPa and the (002) shows a strain hardening effect. In contrast to the HT-orthorhombic phase, LT-tetragonal WB is more isotropic in strength and seems more brittle since no strain hardening was observed. The two phases were found to support a similar maximum differential stress of ˜11 GPa. If it was assumed that t reflects the lower bound of the yield strength, then it is consistent with the microindentation hardness measurements. Additionally, the computation results suggest that W—B bonds contribute the most to the strength of the material.
The embodiments illustrated and discussed in this specification are intended only to teach those skilled in the art how to make and use the invention. In describing embodiments of the invention, specific terminology is employed for the sake of clarity. However, the invention is not intended to be limited to the specific terminology so selected. The above-described embodiments of the invention may be modified or varied, without departing from the invention, as appreciated by those skilled in the art in light of the above teachings. It is therefore to be understood that, within the scope of the claims and their equivalents, the invention may be practiced otherwise than as specifically described.
This application claims the benefit of U.S. Provisional Application No. 62/203,139, filed Aug. 10, 2015, which application is incorporated herein by reference.
This invention was made with Government support under 1106364, 1506860, awarded by the National Science Foundation. The Government has certain rights in the invention.
Filing Document | Filing Date | Country | Kind |
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PCT/US2016/046398 | 8/10/2016 | WO | 00 |
Number | Date | Country | |
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62203139 | Aug 2015 | US |