14 results about "Aluminothermic reaction" patented technology

This invention provides a method for producing high-purity aluminum-niobium-tantalum master alloys and co-producing ammonium fluoride, belonging to the fields of metallic materials and inorganic chemicals. The invention involves mixing fluoroniobic acid, fluorotantalic acid, and ammonia water for a precipitation reaction to obtain a precipitate and an ammonium fluoride solution. The ammonium fluoride solution is then concentrated, cooled for crystallization, dehydrated, and dried sequentially to obtain ammonium fluoride. The precipitate is then dried and oxidized and calcined sequentially to obtain an oxide. The oxide, aluminum powder, potassium chlorate, and calcium fluoride are mixed and subjected to a vacuum aluminothermic reaction to obtain the high-purity aluminum-niobium-tantalum master alloy. This invention, considering both broadening the range of raw material selection and optimizing the production process, reacts fluoroniobic acid, fluorotantalic acid, and ammonia water to produce niobium hydroxide and tantalum hydroxide precipitates, which are then oxidized and calcined to form niobium and tantalum oxides. The high-purity aluminum-niobium-tantalum alloy is then prepared using a vacuum aluminothermic reaction. Simultaneously, ammonium fluoride can be co-produced, resulting in high raw material utilization.

The application discloses a method for controlling the content of aluminum in ferrovanadium alloy, comprising the following steps: calculating the effective oxygen content according to the total content of vanadium oxide, the total content of potassium and sodium, the content of sulfur element and the content of oxygen in volatile sulfur dioxide in the reaction raw materials; calculating the corrected reference aluminum distribution factor according to the effective oxygen content and the reference aluminum distribution formula; calculating the distribution amount according to the demand of preparing ferrovanadium alloy by electric aluminum thermal reaction, wherein the aluminum distribution amount is determined according to the corrected reference aluminum distribution factor; weighing each raw material and mixing the raw materials to obtain a mixture; smelting the mixture by electric smelting; refining; air cooling, disassembling the furnace, removing the alloy cake and water quenching after the refining is completed; crushing and finishing the alloy cake to obtain the ferrovanadium alloy. The application also provides the ferrovanadium alloy prepared by the method. The method can stably control the content of aluminum in the alloy.

The present application relates to a kind of methods for regulating vanadium iron alloy slag characteristics and smelting efficiency, steps are: vanadium oxide, first vanadate, aluminum particle, iron filings and lime are mixed to obtain first batch mixture, vanadium oxide, second vanadate, aluminum particle, iron filings and lime are mixed to obtain second batch mixture, and first and second batch mixture are subjected to aluminothermic reaction respectively, electrode auxiliary heating is used after reaction ends;The above operation is repeatedly performed to carry out N period batch feeding and smelting operation, wherein N≥2 and is integer, and lime is supplemented to form slag before the end of smelting in each of the first to N-1 period, and slagging operation is carried out once;After the N period smelting is completed, lime is supplemented to form slag, and slag iron is discharged after slagging ends.The present application makes full use of the advantages of vanadate, such as large heat release, good mass transfer condition, and by adjusting the addition method of slagging agent, the composition of molten slag at different stages is improved, the characteristics of molten slag are improved, so that efficient reduction and separation of smelting process are realized.

The application discloses a method for laser cladding in-situ synthesis of WO3 and Al2O3 reinforced nickel-based composite layer, relates to the technical field of metal surface modification and laser cladding, and comprises the following steps: spreading high-purity tungsten powder with a particle size of 100-270 mesh in a crucible, heating to 530 DEG C at a heating rate of 10 DEG C / min in a muffle furnace and keeping for 2 h, then air cooling to room temperature, forming a tungsten trioxide coating layer on the surface of tungsten particles, thereby obtaining core-shell structure powder of tungsten trioxide coated tungsten; mixing the core-shell structure powder with high-purity aluminum powder according to a preset mass ratio, and compounding with IN625 nickel-based alloy powder. The application improves the temperature of the molten pool and promotes the full melting of tungsten by constructing the tungsten trioxide core-shell structure and introducing aluminum thermal reaction, so that the cladding layer structure is dense and the energy requirement is reduced; meanwhile, nano-aluminum oxide is generated in-situ and dispersedly distributed, the strength, wear resistance and stability are synergistically improved, and the forming quality consistency and engineering applicability are ensured.

The application discloses a preformed aluminum piece brazing material and a preparation method and application thereof, and belongs to the technical field of brazing. The product is combined with the composite aluminum powder and the magnesium net with the copper oxide shell protection structure, nickel powder is introduced for compounding, heat generated by igniting the magnesium net at a low temperature can initiate the aluminum thermal reaction to release a large amount of heat, and the aluminum powder, the nickel powder and copper generated by the aluminum thermal reaction are combined to form intermetallic compounds or solid solutions under a large amount of heat, so that brazing is realized. In use, the aluminum alloy connecting piece is not worried about being damaged due to overheating caused by high brazing temperature, the energy consumption is low during brazing, and the brazing quality is good.

This invention relates to the field of mold release agent technology, specifically to a graphite mold release agent for forging titanium alloy aircraft blades and its preparation method; the graphite mold release agent for forging titanium alloy aircraft blades comprises the following components by mass percentage: 35-40% lower layer reactive lubricating graphite additive combination, 25-30% upper layer sacrificial activated graphite additive combination, 12-15% deionized water, 8-10% anhydrous ethanol, 3-4% sodium polyacrylate, 1-2% polydimethylsiloxane, and 1-2% polyether-modified poly... The invention comprises siloxane, 3-4% organosilicon resin, and 2-3% polyvinyl alcohol. It achieves a dual-layer, time-sequential synergistic design of a lower reactive lubricating layer and an upper sacrificial activation layer. The upper aluminothermic reaction provides energy to trigger the in-situ generation of a graphite-calcium fluoroborate composite superlubricating phase in the lower layer. Combined with the rare-earth cerium oxide surface modification mechanism, it solves the key problems of traditional graphite release agents being easily oxidized at high temperatures and having poor resistance to titanium adhesion. This provides a new high-performance, long-life, and easy-to-clean graphite release agent solution for the precision forging of titanium alloy aerospace blades.

The present application relates to the technical field of brazing, in particular to a sintering type preformed filler metal, a preparation method and application thereof. The sintering type preformed filler metal comprises a magnesium film, aluminum powder, copper oxide powder and nickel powder attached to the same side of the magnesium film, and an aluminum flux attached to the other side of the magnesium film. The present application takes advantage of the low ignition point of magnesium, which is as low as 490 DEG C, to ignite the magnesium film at a lower temperature during brazing, and the heat generated causes the aluminum powder and copper oxide powder to produce an aluminothermic reaction. The high temperature released by the aluminothermic reaction further causes part of the aluminum powder and the nickel powder and the copper generated by the aluminothermic reaction to form intermetallic compounds or solid solutions, thereby achieving the purpose of brazing connection. Therefore, the present application only needs to apply a temperature of about 500 DEG C to the weld to achieve the purpose of brazing aluminum alloy connecting pieces. The present application solves the problem that the other heat-resistant parts are easily damaged by overheating when using aluminum-based filler metal to braze aluminum alloy connecting pieces, and further reduces the brazing temperature under the premise of ensuring the brazing strength.

This invention discloses a blast furnace pulverized coal additive capable of in-situ disintegration, which is composed of the following raw materials: 15-20 parts by weight of CeO2, 4-8 parts by weight of Cr2O3, 4-8 parts by weight of Ba(MnO4)2, 15-20 parts by weight of MnO2, 15-20 parts by weight of CaO, 15-20 parts by weight of MgO, 20-30 parts by weight of CaF2, 15-24 parts by weight of Fe2O3, 5-8 parts by weight of aluminum powder, and 20-36 parts by weight of urea or ammonium bicarbonate. After being injected into the blast furnace, the blast furnace pulverized coal additive uses an aluminothermic reaction to erode the surface of the carbonaceous material of the pulverized coal into holes or cracks. Furthermore, the combustion reaction of urea or ammonium bicarbonate at high temperatures releases a large amount of gas, causing the pulverized coal additive powder to disintegrate in-situ into smaller particles. This improves the contact efficiency between the pulverized coal additive and the pulverized coal, and also enhances the aluminothermic reaction's erosion effect, thus jointly promoting pulverized coal combustion.

This invention discloses a method and its application for enhancing the bonding strength between a cold-sprayed coating and a substrate based on aluminothermic reaction, belonging to the fields of surface engineering and additive manufacturing technology. The method includes the following steps: using metal powder with an oxide layer on its surface as the cold-spraying raw material, the oxide layer thickness of the metal powder surface being ≤2 μm; using a metal workpiece or a workpiece with a metal surface as the substrate, wherein the metal is selected from elemental aluminum, aluminum alloy, or magnesium alloy; and performing cold spraying on the substrate surface using the metal powder with an oxide layer, causing the oxide layer on the metal powder surface to collide at high speed with the substrate metal, resulting in an aluminothermic reaction that releases the heat of reaction and enhances the bonding strength between the cold-sprayed coating and the substrate. This invention achieves a significant improvement in the bonding strength between the coating and the substrate through in-situ aluminothermic reaction exothermics, while maintaining the low-temperature solid-state deposition advantages of cold spraying technology, broadening the application range of the material, and possessing good industrial application prospects and economic benefits.

This invention discloses a nickel-tantalum master alloy, comprising, by mass percentage: 40.0%–50.0% nickel, with the balance being tantalum and unavoidable impurities. The nickel-tantalum master alloy is prepared from nickel foil, nickel suboxide, tantalum pentoxide, aluminum powder, and calcium granules. The specific preparation method is as follows: nickel suboxide, tantalum pentoxide, and aluminum powder are mixed uniformly to obtain a mixture; calcium granules are spread evenly at the bottom of a crucible in a vacuum aluminothermic reaction furnace, and a layer of calcium oxide slurry is coated onto the inner wall of the crucible. After drying, the mixture is added to perform a vacuum aluminothermic / calcothermic reduction reaction to obtain a nickel-tantalum alloy liquid. After cooling, a primary nickel-tantalum alloy is obtained; tantalum pentoxide is wrapped in nickel foil to form multiple bales; the primary nickel-tantalum alloy is crushed, and the wrapped bales and crushed primary nickel-tantalum alloy are melted in a vacuum electron beam furnace; the melted alloy liquid is cooled to obtain the nickel-tantalum master alloy. The nickel-tantalum master alloy obtained by this invention has high uniformity and high purity.

The application discloses a preformed composite metal foil solder and a preparation method thereof, and relates to the technical field of brazing. The composite metal foil solder comprises a carrier and a plurality of composite foil layers, the plurality of composite foil layers are stacked and deposited on the surface of the carrier, the composite foil layer comprises a copper oxide foil, an aluminum foil and a nickel foil which are stacked and deposited in sequence along the direction away from the carrier, and the carrier is a magnesium foil. The magnesium foil has the advantage of low ignition point, the heat generated by igniting the magnesium foil can stimulate the aluminothermic reaction of the copper oxide foil and the aluminum foil, the high temperature of the aluminothermic reaction makes the aluminum and the nickel foil and the copper generate intermetallic compounds or solid solutions, brazing connection is achieved, the brazing temperature is relatively low and is higher than 500 DEG C, the overheating damage of the aluminum alloy connecting piece to the heat-resistant part can be avoided, the brazing temperature and the leakage rate are reduced, and the sealing effect is improved.

The present application relates to the technical field of drilling pipe external windowing, and provides a pipe external windowing jetting tool and method, the pipe external windowing jetting tool comprising: a main housing, a powder storage cavity is arranged in the main housing, and the main housing can be connected to a drill pipe; a thermite is arranged in the accommodating space; an igniter is arranged in the main housing and can ignite the thermite; a pressure balancing mechanism can balance the powder storage cavity and external pressure before the thermite is ignited; and a jetting assembly is communicated with the powder storage cavity and can jet reaction products of the thermite reaction to the outside of the main housing to melt through a target object. Through the above technical solution, a large amount of heat generated by the thermite reaction is used to heat the reaction products to a molten state, the jetting assembly jets the reaction products in the molten state to the target object, the target object is melted through, the windowing operation is quickly completed, and the pressure balancing mechanism can balance the internal and external pressures to avoid insufficient internal pressure, and the tool can be applied to cementing repair.