308 results about "Transition metal carbides" patented technology

The present methods provide tools for growing conformal metal thin films, including metal nitride, metal carbide and metal nitride carbide thin films. In particular, methods are provided for growing such films from aggressive chemicals. The amount of corrosive chemical compounds, such as hydrogen halides, is reduced during the deposition of transition metal, transition metal carbide, transition metal nitride and transition metal nitride carbide thin films on various surfaces, such as metals and oxides. Getter compounds protect surfaces sensitive to hydrogen halides and ammonium halides, such as aluminum, copper, silicon oxide and the layers being deposited, against corrosion. Nanolaminate structures incorporating metallic thin films, and methods for forming the same, are also disclosed.

The present invention relates to compositions and methods for forming a bit body for an earth-boring bit. The bit body may comprise hard particles, wherein the hard particles comprise at least one carbide, nitride, boride, and oxide and solid solutions thereof, and a binder binding together the hard particles. The binder may comprise at least one metal selected from cobalt, nickel, and iron, and at least one melting point reducing constituent selected from a transition metal carbide in the range of 30 to 60 weight percent, boron up to 10 weight percent, silicon up to 20 weight percent, chromium up to 20 weight percent, and manganese up to 25 weight percent, wherein the weight percentages are based on the total weight of the binder. In addition, the hard particles may comprise at least one of (i) cast carbide (WC+W2C) particles, (ii) transition metal carbide particles selected from the carbides of titanium, chromium, vanadium, zirconium, hafnium, tantalum, molybdenum, niobium, and tungsten, and (iii) sintered cemented carbide particles.

The present invention relates to compositions and methods for forming a bit body for an earth-boring bit. The bit body may comprise hard particles, wherein the hard particles comprise at least one carbide, nitride, boride, and oxide and solid solutions thereof, and a binder binding together the hard particles. The binder may comprise at least one metal selected from cobalt, nickel, and iron, and, optionally, at least one melting point reducing constituent selected from a transition metal carbide in the range of 30 to 60 weight percent, boron up to 10 weight percent, silicon up to 20 weight percent, chromium up to 20 weight percent, and manganese up to 25 weight percent, wherein the weight percentages are based on the total weight of the binder. In addition, the hard particles may comprise at least one of (i) cast carbide (WC+W2C) particles, (ii) transition metal carbide particles selected from the carbides of titanium, chromium, vanadium, zirconium, hafnium, tantalum, molybdenum, niobium, and tungsten, and (iii) sintered cemented carbide particles.

The present method provides tools for growing conformal metal nitride, metal carbide and metal thin films, and nanolaminate structures incorporating these films, from aggressive chemicals. The amount of corrosive chemical compounds, such as hydrogen halides, is reduced during the deposition of transition metal, transition metal carbide and transition metal nitride thin films on various surfaces, such as metals and oxides. Getter compounds protect surfaces sensitive to hydrogen halides and ammonium halides, such as aluminum, copper, silicon oxide and the layers being deposited, against corrosion. Nanolaminate structures (20) incorporating metal nitrides, such as titanium nitride (30) and tungsten nitride (40), and metal carbides, and methods for forming the same, are also disclosed.

The invention provides a preparation method of porous graphene. The method comprises the steps of: heating a carbon material and an activator; obtaining the porous graphene after reaction, wherein the carbon material is modified graphene or graphene, and the activator is a transitional metal or a transitional metal compound; in the process of preparing the porous graphene, heating the graphene or the modified graphene and the activator: the transitional metal or the transitional metal compound to form a transitional metal carbide; further decomposing the transitional metal carbide into carbon and transitional metal to obtain the transitional metal for continuously reacting with the graphene; and circulating in this way to finally obtain the porous graphene. Compared with the prior art, as the transitional metal and the carbon material are reacted circularly, the porous graphene with larger aperture range can be obtained. Experimental result shows that the diameter of the porous graphene prepared by the invention is 1-100nm.

The invention provides a cellulose/two-dimensional layered material composite hydrogel. The composite hydrogel comprises a cellulose three-dimensional network structure and a two-dimensional materialsupported in the cellulose three-dimensional network structure, wherein the two-dimensional layered material is a two-dimensional transition metal carbide, nitride, or carbonitride. According to the composite hydrogel provided by the invention, the two-dimensional layered material can be stably supported in the composite hydrogel system and is not easy to agglomerate; and the composite hydrogel has good compatibility with a biological fluid, and the advantages of full biodegradability and high biological safety, and can be used in the field of biomedicines. The invention also provides a preparation method of the composite hydrogel.

A preparation method of a two-dimensional nitrogen-doped carbon-based titanium dioxide composite material includes: (1) etching Ti₃AlC2 with LiF/HCl to prepare two-dimensional transition metal carbide nanosheet; (2) preparing a nanosheet aggregate by electrostatic self-assembly of a two-dimensional transition metal carbide nanosheet and a positively charged nitrogen-containing cationic compound; (3) calcining the nanosheet aggregates to prepare a two-dimensional nitrogen-doped carbon-based titanium dioxide composite material. A method for degrading and removing organic pollutants in water includes (1) etching Ti₃AlC₂ with LiF/HCl to prepare two-dimensional transition metal carbide nanosheet; (2) preparing a nanosheet aggregate by electrostatic self-assembly of a two-dimensional transition metal carbide nanosheet and a positively charged nitrogen-containing cationic compound; (3) calcining the nanosheet aggregates to prepare a two-dimensional nitrogen-doped carbon-based titanium dioxide composite material; (4) placing the two-dimensional nitrogen-doped carbon-based titanium dioxide composite material into water containing organic pollutants to degrade and remove organic pollutants in water.

The present invention relates to compositions and methods for forming a bit body for an earth-boring bit. The bit body may comprise hard particles, wherein the hard particles comprise at least one carbide, nitride, boride, and oxide and solid solutions thereof, and a binder binding together the hard particles. The binder may comprise at least one metal selected from cobalt, nickel, and iron, and, optionally, at least one melting point reducing constituent selected from a transition metal carbide in the range of (30) to (60) weight percent, boron up to (10) weight percent, silicon up to (20) weight percent, chromium up to (20) weight percent, and manganese up to (25) weight percent, wherein the weight percentages are based on the total weight of the binder. In addition, the hard particles may comprise at least one of (i) cast carbide (WC + WC) particles, (ii) transition metal carbide particles selected from the carbides of titanium, chromium, vanadium, zirconium, hafnium, tantalum, molybdenum, niobium, and tungsten, and (iii) sintered cemented carbide particles.

The invention provides a two-dimensional slice material enhanced metal-based composite. According to the composite, metal is adopted as a base body, two-dimensional transition metal carbide or carbonitride, namely, MXenes is adopted as a reinforced phase, and MXenes particles are evenly dispersed in metal base body particles. Due to the fact that the MXenes material comprises a hollow carbon position and tends to metallicity, the metal base body has good wettability, and the interface bonding strength of the metal-based composite can be effectively improved. Therefore, the mechanical performance, wear resistance and other performance of the metal-based composite are enhanced. Meanwhile, the electronic coupling effect of the MXenes material and a metal base body interface is better, and the problem that in the prior art, the mechanical performance and corrosion resistance of the metal-based composite are improved through the reinforced phase, and meanwhile the heat conducting and electrical conducting performance of the metal-based composite is reduced can be avoided.

The invention discloses a super-hard five-component transition metal carbide single-phase high-entropy ceramic material and a preparation method thereof, belongs to the technical field of super-hard ceramic materials, and particularly relates to a super-hard single-phase high-entropy ceramic material and a preparation method thereof. In the prior art, the existing multi-component carbide preparation method can cause oxygen pollution, and the density is difficultly increased. A purpose of the present invention is to solve the problems in the prior art. According to the present invention, the super-hard five-component transition metal carbide single-phase high-entropy ceramic material has a chemical formula of (Tix1Zrx2Nbx3Tax4Mx5)C; the preparation method comprises: 1, weighing, 2, mixing,3, calcining, 4, high temperature sintering, and 5, demolding; and with the method, the density and the mechanical properties of the carbide are improved, the significant solid solution strengtheningeffect and the high density significantly improve the hardness of the material, and the super-hard five-component transition metal carbide single-phase high-entropy ceramic material can be obtained.

The invention relates to a metallic carbide/carbon composite coating prepared on the surface of a carbon material and a method thereof. The method comprises the following steps: placing the carbon material into a chemical vapor deposition furnace, introducing propylene and nitrogen of which flow rates are 100 to 800sccm and 100 to 2,000sccm respectively into the furnace, simultaneously heating the carbon material to between 700 and 1,300 DEG C at a rate of 1 to 20 DEG C per minute, and preserving the heat for 40 to 120 hours to obtain the carbon material of which surface is deposited with a pyrolytic carbon coating; placing the carbon material into a crucible, covering a mixture of 1 to 1.9 times of assistant and 0.01 to 1.2 times of transition metal powder in terms of the carbon material on the carbon material, heating the carbon material to between 600 and 1,200 DEG C at a rate of 1 to 30 DEG C per minute under the atmosphere of the nitrogen, preserving the heat for 1 to 20 hours, cooling the mixture and then taking out a product, washing the product by water and drying the product to obtain the composite coating. The method can prepare various transition metallic carbide/carbon composite coatings on the surface of the carbon material, the thickness and form of the coating are controllable, the combination of the coating and the carbon material basal body is good, and the properties of high-temperature oxidation resistance and ablation resistance of a base material are improved.

The invention discloses a composite nanostructure based on a three-dimensional porous transition metal carbide Ti3C2MXene and a general preparation method thereof, and belongs to the field of nanomaterials. The three-dimensional composite structure is composed of a three-dimensional porous Mxene-supported inorganic nanostructure, and has a honeycomb hierarchical porous structure. A precursor of atwo-dimensional transition metal carbide and a metal-organic framework compound is subjected to high-temperature pyrolysis or a chemical reaction in an inert or reactive atmosphere to prepare the composite nanostructure with a controllable size. According to the composite nanostructure, stacking of MXene itself is inhibited, an active surface area, porosity, and ion permeability of MXene are increased, and thereby a surface interface of MXene is efficiently used. At the same time, introduction of the metal-organic framework compound realizes uniform and stable compounding of the three-dimensional porous MXene and an inorganic nanomaterial, the fundamental difficult problem that plagues exerting and application of inorganic nanomaterial performance is solved, and the composite nanostructurehas wide application prospects in the fields such as catalysis, energy, photo-electricity, space technology, and military industry.

A catalyst composition contains an active metal on a support including a high surface area substrate and an interstitial compound, for example molybdenum carbide. Pt—Mo₂C/Al₂O₃ catalysts are described. The catalyst systems and compositions are useful for carrying out reactions generally related to the water gas shift reaction (WGS) and to the Fischer-Tropsch Synthesis (FTS) process.

The invention provides a carbon/alumina composite carrier catalyst used for hydrazine decomposition reaction and a preparation method thereof. The catalyst showed in the formula is A/C-Al2O3, C-Al2O3 is the carbon/alumina composite carrier, and active constituent A is transition metal Mo, W, Fe, Co, Ni, Ru, Rh, Pd, Ir, Pt or carbonization, nitride and phosphide thereof; wherein, the content of the A is 2-40wt percent and the preparation temperature of the A is 300-900 DEG C. The invention has simple preparation, especially for the preparation of active species of the transitional metal carbonization, which uses H2 instead of CH4/H2 gas used in the past preparation to have direact reduction; the invention prevents carbon deposition on the surface of the carbonization from inactivating, thus being beneficial to acquire more catalytic active sites.

The invention provides a preparation method of a carbon onion loaded transition metal carbide nano composite, comprising the following steps of: uniformly mixing reactant in proportion and then loading the reactant into a closed reaction kettle, wherein a hydrocarbon compound, molybdenum salt or tungsten salt and a nitrocompound are taken as raw materials; and heating the reaction kettle and utilizing a chemical vapor deposition method assisted by an initiator to react for one time to obtain a target product. The preparation method disclosed by the invention has the advantages of simple process and equipment, convenience for operation, fast reaction speed and low energy consumption; the output of the carbon onion and the transition metal carbide nano composite is great, the grain diameter of a carbon onion carrier is controllable, the metal carbide has small granularity and is dispersed uniformly; and the composite is used as a catalyst in a catalyzing field or is used as an additive of a lubricant in a friction field, so as to have an important application value.

An article is provided including a heating element and a high temperature coating coated on the heating element. The high temperature coating comprises a first region and a second region arranged in a structure such that the first and second regions maintain a periodicity of distribution between about 100 nm and about 1000 nm. Furthermore, the first region includes a first material selected from the group consisting of carbides of transition metals, nitrides of transition metals, and borides of transition metals.

The invention provides a carbide crystal material with a two-dimensional lamellar structure. The carbide crystal material with the two-dimensional lamellar structure is composed of transition metal elements and carbon element, and the atomic ratio of the transition metal elements to the carbon element is less than or equal to 1. According to the preparation method of the carbide crystal material with the two-dimensional lamellar structure, ternary or polybasic Zr/Hf/Y-Al/Si/Ge-C lamellar ceramic material is used as a precursor and is subjected to selective corrosion so that an Al-C lamella with a weak valence bond can be peeled off and corroded, thus obtaining the carbide crystal material with the two-dimensional lamellar structure. The method is simple and practicable, and has the advantage that the composition elements, element stoichiometric ratio, morphology and structure of the carbide crystal material with the two-dimensional lamellar structure are all designable and controllable. The carbide crystal material with the two-dimensional lamellar structure has good applications in the fields of electrode materials for electrochemical energy storage, functional macromolecular conductive fillers, sensors, catalysts, transparent conductors and the like.

This invention belongs to the technical field of transition metal carbide-carbon material, and specifically provides a molybdenum carbide/ graphene/carbon nanofiber composite material, and a preparation method thereof. The preparation method comprises the following steps: preparing and obtaining a polyacrylonitrile nanofiber film through electrostatic spinning; coating the oxidized graphene on the polyacrylonitrile nanofiber film through a solution immersion method; preparing a graphene/carbon nanofiber composite film through high-temperature carbonization; acidizing the obtained composite film; at last, in-situ growing molybdenum carbide nanospheres on the graphene/carbon nanofiber composite film through a one-step hydrothermal method and the high-temperature carbonization. The molybdenum carbide/ graphene/carbon nanofiber composite material prepared by this method has a controllable shape, has the higher specific surface area and excellent conductivity, and can be used as an ideal high-performance electro-catalysis material, and the electrode material of the new-energy devices, such as the lithium ion battery, the super capacitor, and so on.

A method of producing coated ultra-hard abrasive material, in particular coated diamond and CBN material. In a first step, an element capable of forming (singly or in combination) carbides, nitrides or borides to the surface(s) of the abrasive material is is applied using a hot coating process. At least one outer layer of a coating material selected from the group comprising transition metals, carbide, nitride, boride, oxide and carbonitride forming metals, metal carbides, metal nitrides, metal borides, metal oxides and metal carbonitrides, boronitrides and borocarbonitrides is applied over the inner layer by physical vapour deposition or chemical vapour deposition. Typically the inner layer elements come from groups IVa, Va, VIa, IIIb and IVb of the periodic table and include, for example, vanadium, molybdenum, tantalum, indium, zirconium, niobium, tungsten, aluminium, boron and silicon. The outer coating is preferably applied by reactive sputtering where a reactive gas is admitted to the sputtering chamber, resulting in the deposition of a compound of the reactive gas and the element being sputtered.