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

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.

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 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 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.