13 results about "Self-propagating high-temperature synthesis" patented technology

The present invention provides a method and apparatus for synthesizing oxygen-vacancy nano-tin oxide using waste raw materials. The method uses industrial and agricultural waste as raw materials and realizes the preparation of oxygen-vacancy nano-tin oxide through self-propagating high-temperature synthesis technology and the regulation of a flowing mixed atmosphere with an oxidizing function. The nano-tin oxide product prepared by the present invention has the advantages of high purity, good dispersibility, adjustable oxygen vacancy content, and good photocatalytic performance. While proposing a method for preparing nano-tin oxide with adjustable oxygen vacancy content, the method and apparatus provided by the present invention reduce the energy consumption and raw material costs of existing oxygen-vacancy nano-tin oxide production, improve its production efficiency, and achieve safe disposal of waste, greatly reducing environmental pressure. It has good economic and environmental benefits and has broad prospects for promotion and application.

The invention designs a method for plating metal tungsten on the surfaces of diamond particles by comprehensively utilizing sol-gel and a self-propagating high-temperature synthesis technology, which mainly comprises the following steps of: dissolving a tungsten source in liquid to prepare sol, then adding the diamond particles into the sol, stirring to obtain diamond coated with the sol, and finally, carrying out heat treatment on the diamond coated with the sol. Carrying out calcination and self-propagating high-temperature treatment on the diamond coated with the sol; the ignition temperature of the self-propagating high-temperature treatment is 600-1200 DEG C, a substance used in the self-propagating high-temperature treatment contains a solid reducing agent, the solid reducing agent can reduce non-zero-valent tungsten into zero-valent tungsten, the calcining temperature is greater than 600 DEG C and less than or equal to 700 DEG C, and the calcining time is less than or equal to 5 hours. According to the method, a self-propagating high-temperature rapid reduction method is used for plating the tungsten layer on the diamond for the first time, the plating layer is compact and is well combined with the diamond, and industrial application is facilitated.

This invention discloses a method for preparing ceramic-based composite coatings using a laser-induced self-propagating high-temperature synthesis method based on powder-core wire. This method combines laser filament melting technology with a self-propagating high-temperature synthesis method, utilizing a high-energy laser beam to trigger the periodic self-propagating combustion reaction of the powder-core wire. Using powder-core wire instead of powder as the precursor material for coating preparation effectively reduces the dilution effect of the titanium alloy substrate on the coating microstructure. This method can synthesize ceramic-based composite coatings with a dense and uniform microstructure and microhardness values ​​close to the theoretical values, showing broad application prospects.

This invention discloses a method for preparing a nickel-titanium alloy ingot containing a low-melting-boiling-point metal, comprising: Step 1: placing a first nickel rod vertically and making a hole to form a receiving hole; Step 2: filling the receiving hole with low-melting-boiling-point metal particles; Step 3: placing a second nickel rod on top of the first nickel rod and then welding them to obtain a binary alloy preform; Step 4: placing the binary alloy preform in a crucible, with the second nickel rod placed close to the bottom of the crucible; Step 5: placing the crucible containing the binary alloy preform in a vacuum induction melting furnace for melting to obtain a binary alloy body; Step 6: pressing sponge titanium, electrolytic nickel blocks, and the binary alloy body in a pressing machine to obtain an electrode. This invention does not require specialized equipment and does not incur additional equipment purchase costs. Compared with additive manufacturing and self-propagating high-temperature synthesis methods, it has advantages such as low cost, high efficiency, and high yield.

Articles are manufactured using self-propagating high-temperature synthesis (SHS) reactions. Particulates including reactants can be blended to form a particulate blend. The particulate blend can be preformed. The preform article can be heated to a pre-heat temperature being below an auto-activation temperature and above a minimum compression activated synthesis temperature. Compressive stress can be exerted on the preform article at the pre-heat temperature to initiate the SHS reaction between the reactants and thereby form a product metallic compound. At approximately peak temperature, a flow stress of the product metallic compound can be exceeded to substantially reduce porosity and thereby form a shaped substantially dense article.

The invention discloses a composite spraying material for an electrolytic aluminum anode and a preparation method of the composite spraying material, and relates to the technical field of electrolytic aluminum metallurgy new materials, and the composite spraying material comprises the following components in percentage by weight: 42%-45% of aluminum-based high-entropy oxide, 18%-22% of a structure enhancer, 5%-8% of a composite glazing agent, 3%-5% of a film forming regulator, 1%-3% of a bonding system and the balance of deionized water, the aluminum-based high-entropy oxide is prepared from aluminum, iron, magnesium, copper and nickel according to the molar ratio of 0.62: 0.14: 0.04: 0.09: 0.07 through mechanical alloying and self-propagating high-temperature synthesis. The protection performance and the purity of molten aluminum are guaranteed, and the component design is more reasonable. The aluminum-based high-entropy oxide is subjected to accurate molar ratio regulation and control and matched with a structure enhancer to form a compact protection framework, the oxidation resistance is improved by 40% or above compared with a traditional aluminum oxide coating, erosion of oxygen, hydrogen fluoride and cryolite slag at the temperature of 950-1000 DEG C can be effectively resisted, core components are compatible with electrolytic raw materials, no impurity element is introduced, and the service life of the electrolytic coating is prolonged. And even if a small amount of coating falls off, molten aluminum cannot be polluted, and the quality of electrolytic products is guaranteed.

The utility model discloses self-propagating high-temperature synthesis equipment with preheating driving, which comprises a furnace body and a furnace cover, and an induction coil heater, a resistance heater and a forward pressure driving device are arranged in the furnace body; the induction coil heater, the resistance heater and an external power supply form a loop; according to the self-propagating high-temperature synthesis equipment, complete reaction of combustion synthesis reaction can be effectively promoted, the combustion temperature gradient is remarkably reduced through the self-propagating high-temperature synthesis equipment combining resistance preheating, induction heating and forward high-pressure driving, and the defects of large product stress, insufficient compactness and the like are overcome. Meanwhile, the sintering activity and purity of the product are improved, and the high efficiency of combustion synthesis reaction is promoted.

The invention discloses a self-propagating and additive manufacturing composite preparation method of an AgBiSe2 thermoelectric device. The method comprises the steps that green body raw materials including Ag powder, Bi powder and Se powder are mixed and tableted, and then a green body is obtained; heating the green body to initiate a self-propagating high-temperature synthesis reaction, and after the reaction is finished, crushing and grinding to obtain thermoelectric device precursor powder; after the precursor powder is subjected to size mixing, 3D printing and sintering are sequentially carried out, and the 3D printing material is obtained. The method is based on a self-propagating-additive manufacturing composite process, not only is the preparation period of the thermoelectric device shortened from more than 10 hours to several minutes exponentially, but also the structure adjustability, controllability and integrated forming of the thermoelectric device are realized, and the thermoelectric performance of the material is greatly improved on the premise of ensuring the mechanical performance of the thermoelectric device.

The invention discloses a preparation method and application of a nano-porous ceramic rare earth-based denitration and dechlorobenzene catalyst. The catalyst takes a composite oxide of titanium dioxide and magnesium oxide as a carrier, takes a composite oxide of nickel oxide and cerium dioxide as an active component, takes bacillus subtilis as a structure-directing agent and takes magnesium powder as a combustion agent; according to the invention, sodium perchlorate is taken as an initiator, ammonium bicarbonate is taken as a pore-forming agent, and a biological template method, a freezing pore-forming method, a self-propagating high-temperature synthesis method and an impregnation loading method are combined for preparation. The catalyst synthesized by the invention has the advantages of large specific surface area, sufficient exposure of active sites and the like, and can realize simultaneous denitration and chlorobenzene removal of complex flue gas in the non-electric industry.

The invention discloses an iron-based ceramic composite wear-resistant material and a preparation method and application thereof, and belongs to the technical field of ferrous metallurgy and metal materials. The material comprises a metal matrix, a wear-resistant layer and an element interdiffusion band formed by metallurgical bonding of the metal matrix and the wear-resistant layer, the width of the element interdiffusion band is 0-110 microns, the wear-resistant layer comprises the following chemical components in percentage by mass: 15-30% of a hard phase, 50-80% of iron and 10-25% of chromium, the sum of the mass ratios of the hard phase, the iron and the chromium is 100%, and the hard phase is composed of TiC and TiB2. According to the preparation method, titanium powder, B4C powder, aluminum powder, magnesium powder, Fe3O4 and CrO3 powder serve as raw materials, and the product is obtained through a self-propagating high-temperature synthesis reaction and used for preparing high-abrasion parts. The invention aims to obtain the iron-based ceramic composite wear-resistant material which is uniform in structure, high in density, high in hardness, excellent in wear resistance and good in metallurgical bonding with a metal matrix.

The invention provides a Mn-doped iron-cobalt-nickel-based medium-entropy alloy aerogel material as well as a preparation method and application thereof, and relates to the technical field of electromagnetic wave absorbing materials. With glycine as an auxiliary agent, preparing a precursor through a self-propagating high-temperature synthesis method; after the precursor is compressed, the alloy aerogel with the three-dimensional porous network structure is prepared in combination with a high-temperature reduction process, and the preparation scheme is simple, convenient and easy to implement. The medium-entropy alloy is combined with aerogel, the electromagnetic performance of the medium-entropy alloy material is accurately regulated and controlled through Mn element doping, and effective absorption of electromagnetic waves can be achieved under the low matching thickness; and by adjusting the matching thickness, efficient absorption of low-frequency electromagnetic waves can be realized. In addition, the material is low in density, and the problem that a traditional alloy wave-absorbing material is thick and heavy is solved. The iron-cobalt-nickel-based entropy alloy aerogel has excellent electromagnetic wave absorption performance and is suitable for the fields of electromagnetic shielding, radar stealth and the like.

The invention discloses a preparation method of a metal ceramic composite material for resisting material abrasion, and belongs to the technical field of composite materials. The method specifically comprises the steps that in the process that molten metal liquid flows through a pouring articulated chute, precursor particles are evenly guided into metal liquid flow through a high-pressure gas auxiliary injection device, in the process that a casting cavity is filled with the metal liquid with the precursor particles, the precursor particles and a metal matrix are subjected to a self-propagating high-temperature synthesis reaction, and the ceramic reinforced phase is generated in situ. Gradient distribution and interface metallurgical bonding of ceramic particles in a metal matrix are achieved by regulating and controlling the synergistic effect of the flowing state of the molten metal and the spraying parameters of the precursor. And after the casting is cooled, the ceramic particle reinforced metal matrix composite is finally obtained. By means of the process method, in-situ synthesis of the ceramic reinforced phase and integrated forming of the composite material are achieved, the preparation efficiency is remarkably improved, the production cost is reduced, and good process controllability and automatic production adaptability are achieved.

The invention provides a method for self-propagating high-temperature synthesis of coal-based mullite multiphase ceramic from coal gangue, which comprises the following steps: proportioning coal gangue, carbon black and silicon powder according to a certain mass ratio, ball-milling and mixing by absolute ethyl alcohol, drying, placing in a high-pressure reaction device together with an ignition agent titanium powder, and electrifying to ignite the titanium powder to initiate a self-propagating reaction under the nitrogen atmosphere of 6-8MPa. The coal gangue is converted into a functional reaction raw material and a sintering aid from waste to be treated by utilizing the characteristic of complex components of the coal gangue, and impurity oxides such as K2O, Na2O, Fe2O3 and the like contained in the coal gangue can form a low-melting-point silicate liquid phase at a self-propagating high temperature, so that a self-catalysis sintering effect is realized. According to the method, only mechanical crushing and ball milling are needed, so that the energy consumption and the cost are reduced.