1017 results about "Oxidation resistance" patented technology

The invention discloses a low-carbon magnesia-carbon refractory material for clean steel smelting and a preparation method thereof, and relates to the technical field of magnesia-carbon refractory materials. The low-carbon magnesia-carbon refractory material comprises the following components: 40-50 wt% of fused magnesite with the particle size of 3-5 mm, 20-30 wt% of fused magnesite with the particle size of 1-3 mm, 10-20 wt% of fused magnesite with the particle size of less than or equal to 74 [mu] m, 8-12 wt% of silicon powder, 1-3 wt% of alumina powder and 3-5 wt% of crystalline flake graphite. 2-4 wt% of a composite additive and 4-6 wt% of phenolic resin are added; the composite additive comprises andalusite and mullite. The material has excellent mechanical properties, thermal shock resistance, oxidation resistance and erosion resistance; the preparation method has the characteristics of low cost and simple process, and the prepared low-carbon magnesia carbon refractory material has excellent oxidation resistance, thermal shock resistance and slag resistance by exerting the phase volume expansion effect and intergranular phase enhancement effect of the multiphase ceramic; the used graphite is low in content, graphite consumption and molten steel recarburization risk can be reduced, and the method is suitable for smelting clean steel.

The invention belongs to the technical field of nickel-based alloy welding wires, and discloses a corrosion-resistant nickel-based alloy welding wire and a production process thereof, and the corrosion-resistant nickel-based alloy welding wire comprises the following components in percentage by mass: 50-65% of nickel, 16-24% of chromium, 8-10% of molybdenum, 3.5-5.5% of niobium and tantalum, 3-4.5% of copper, 3-4% of tungsten, 0.5-1.0% of tin, 0.1-0.3% of rare earth element, 0.1-0.5% of grain boundary optimizer, 2-5% of nano reinforced phase and the balance of Fe and other inevitable impurities. Through multi-element alloying design, nano reinforced phase compounding and gradient coating synergistic effect, comprehensive improvement of corrosion resistance, high-temperature mechanical property and welding manufacturability is achieved; a welding wire base body is based on nickel, a compact and self-repairing gradient oxidation film is formed by accurately regulating and controlling the atomic proportion of chromium, molybdenum and tungsten, and the chloride ion permeation resistance and the high-temperature oxidation resistance are remarkably improved; therefore, the welding wire has excellent corrosion resistance, high-temperature strength and welding adaptability.

The invention relates to the technical field of environment-friendly additives, and discloses an environment-friendly additive for soil pollution remediation and an application method thereof.The environment-friendly additive is prepared from 5-20 parts of nano zero-valent iron, 2-15 parts of a nano carbon material and 3-18 parts of a nano mineral composite material; 5-25 parts of biochar, 2-10 parts of microbial flora and 1-10 parts of a plant source extract; 1-8 parts of a pH responsive material; 2-10 parts of a microcapsule material; the particle size range of the nanoscale zero-valent iron is 10-100 nm, and SiO2 or C is coated on the surface of the nanoscale zero-valent iron; the nano carbon material is selected from activated carbon nanoparticles, graphene and carbon nanotubes. The carbon-coated nano zero-valent iron is adopted, so that the technical effects of improving the oxidation resistance of the material and prolonging the active life are achieved. Compared with a traditional technical scheme without coating nZVI, the problems that the composite material is prone to oxidation inactivation and insufficient in long-term repair capacity are solved, and the composite material has more stable heavy metal removal performance in a complex environment.

The 430-series stainless steel has good corrosion resistance and oxidation resistance, and is widely applied to the fields of buildings, decoration, household appliances, kitchen ware and the like due to the excellent performance and relatively low price of the 430-series stainless steel. As cover annealing is not carried out on 430, and the 430 is directly subjected to acid pickling and cold rolling through air cooling after hot rolling, adverse factors which influence cold rolling, such as edge cracking, high hardness of heads and tails, high strength and the like, are easy to occur in cold rolling. According to the annealing-free direct rolling method for the low-cost 430 stainless steel, slow cooling and heat preservation are conducted on the hot-rolled 430 stainless steel, the microscopic structure of the 430 stainless steel has the obvious grain recovery characteristic, the yield strength and tensile strength are reduced, the hardness is reduced, the plasticity is improved, the problems that the low-cost 430 stainless steel is high in hardness and poor in plasticity due to the fact that annealing is not conducted can be remarkably solved, cold rolling is better facilitated, and the service life of the low-cost 430 stainless steel is prolonged. And after slow cooling treatment, the problems of edge cracking, difficult rolling and the like do not occur in the cold rolling process of 430. The slow cooling heat preservation cover has an improvement effect on solving the problem of low-cost rolling 430 in the cold rolling process, and development of a low-cost cover-free annealing process and trial production of new products are facilitated.

The invention discloses a graphite piece silicon carbide coating and a preparation method thereof, and belongs to the technical field of inorganic non-metallic materials. The method comprises the following steps: firstly, carrying out surface polishing, cleaning and drying pretreatment on a graphite piece; then a solution containing phosphinazine functionalized silazane and a boron-silicon carlamide compound is adopted for spraying the pretreated graphite piece, drying and curing are conducted, and a surface modification layer is formed; and finally, placing the surface-modified graphite piece in chemical vapor deposition equipment, and depositing at specific temperature, pressure and atmosphere to form the silicon carbide coating. According to the method, uniform nucleation and crystallization of the silicon carbide coating are effectively promoted through unique surface modification treatment, and the compactness and uniformity of the coating and the binding force of the coating and a matrix are remarkably improved. The obtained coating graphite piece has excellent thermal corrosion resistance, oxidation resistance and mechanical property, the service life and the use frequency of the coating graphite piece in semiconductor epitaxial equipment are remarkably prolonged, the whole preparation process is environmentally friendly, and the coating graphite piece is suitable for coating treatment of a large graphite base material.

The invention provides a silver-coated copper material and a preparation method and application thereof. The silver-coated copper material comprises a base body and a silver layer coated on the surface of the base body, the base body comprises copper particles and a silver framework, the silver framework is provided with holes, the copper particles are distributed in the holes of the silver framework, and the silver layer is prepared by adopting a chemical plating method. The pore structure of the silver skeleton and the distribution of the copper particles are utilized, the separation of nucleation and growth of the silver coating is realized, the uniformity and compactness of the growth of the silver coating are ensured, the oxidation resistance and the conductivity of the silver-coated copper material are further improved, the use amount of precious metal silver is greatly reduced while the performance of the material is ensured, and the production cost is reduced. Cost control is realized; when the silver-coated copper material is applied to the fields of photovoltaic and electronic industry, the cost of raw materials can be remarkably reduced, the service life of the raw materials is prolonged, and large-scale use is facilitated.

The invention relates to the field of table tennis bat rubber materials, in particular to aging and oxidation resistant table tennis bat rubber and a preparation method thereof, and aims to solve the problems that existing table tennis bat rubber is poor in aging and oxidation resistance and wear resistance, performance of table tennis bat is easily reduced, and competition experience of athletes is affected. According to the preparation method, the obtained table tennis bat rubber has excellent aging and oxidation resistance and wear resistance, the surface of the rubber is kept smooth and free of obvious wear and aging phenomena in the long-time use process, and the service life of a table tennis bat is effectively prolonged. In addition, the rubber sheet has good elasticity and ball touching feeling, can improve the ball hitting quality and competition experience of athletes, and has important significance for improving the performance of the table tennis bat. Meanwhile, the preparation method is simple in process, easy to realize industrial production and wide in application prospect.

The invention provides nitrogen / sulfur co-doped charcoal loaded nano zero-valent iron as well as a preparation method and application thereof, and relates to the technical field of sewage treatment. The nitrogen / sulfur co-doped biochar loaded nano zero-valent iron is a composite material prepared by taking nitrogen / sulfur co-doped biochar as a carrier material and loading nano zero-valent iron; the nitrogen / sulfur co-doped biochar is prepared from the following raw materials: melamine, diphenyl disulfide and walnut shells. The nitrogen / sulfur co-doped biochar loaded nano zero-valent iron prepared by the invention combines the porous characteristic of biochar and the high reaction activity of nano zero-valent iron, not only has excellent oxidation resistance and corrosion resistance, but also retains good hydrophilicity and magnetism, can efficiently remove antibiotic pollutants in the environment, and has a good application prospect. And actual operation and recycling are facilitated.

The utility model relates to the technical field of inflatable hoses, in particular to a high-performance wear-resistant extremely-cold-resistant inflatable hose. The inflation hose comprises a metal corrugated pipe, the metal corrugated pipe is sleeved with a steel wire mesh sleeve, the steel wire mesh sleeve is sleeved with a long connecting pipe, the long connecting pipe is sleeved with a vulcanization layer, one end of the metal corrugated pipe is connected with a long inner cone connecting nozzle in an inserted mode, and the outer surface of the long inner cone connecting nozzle is sleeved with a nut in a threaded mode. And a long outer cone connecting nozzle is inserted into the other end of the steel wire mesh sleeve. The inflatable hose can meet the requirement of a dew point of-65 DEG C by adopting a metal corrugated pipe structure, can meet the requirements of 40MPa working pressure and 120MPa bursting pressure structure by adopting a steel wire mesh sleeve structure and adopting a high-pressure brazing form after double-layer weaving, and meanwhile, the vulcanization layer is arranged outside the long connecting pipe in a sleeving manner, so that the service life of the long connecting pipe is prolonged. Therefore, the inflatable hose has excellent oxidation resistance, ozone resistance and erosion resistance.

The invention discloses a modified PET recycled material and a preparation method thereof, and belongs to the technical field of plastic recycling. Comprising the following raw materials in parts by weight: 70-90 parts of a pretreated PET reclaimed material, 8-24 parts of modified graphene oxide, 3-9 parts of an antioxidant and 3-5 parts of a lubricant. Wherein the antioxidant can achieve a synergistic effect, so that the oxidation resistance of the PET recycled material is greatly improved; wherein the modified graphene oxide has good compatibility with a PET matrix, and can play a synergistic effect with groups on the surface of the modified graphene oxide, so that the flame retardance, antibacterial property and certain heat resistance of the PET recycled material are remarkably enhanced; therefore, the PET recycled material is modified and recycled, the pollution of waste materials is reduced, the recycling of resources is realized, and the modified PET recycled material also has excellent oxidation resistance, stable and efficient flame retardance, antibacterial property and heat resistance to a certain degree, and has important application value in the technical field of plastic recycling.

The invention discloses a rare earth metal ceramic and a preparation method thereof, and belongs to the technical field of metal ceramic preparation, the rare earth metal ceramic comprises, by mass, 45-65% of a ceramic phase, 30-50% of a metal binding phase and 3-8% of a rare earth additive, the ceramic phase is composed of one of TiC and WC and one of Al2O3 and ZrO2, the metal binding phase is composed of a Ni-Co alloy and Mo or Cr, and the rare earth additive is composed of one of Al2O3 and ZrO2. The rare earth additive is composed of mixed rare earth oxide and nano rare earth fluoride. The invention further provides a preparation method of the rare earth additive. Through the synergistic effect of oxide grain boundary purification and fluoride liquid phase sintering in a two-phase rare earth system, the problem that traditional single rare earth is difficult to add and disperse is solved, through staged hot pressing sintering, dual optimization of grain refinement and density improvement is achieved, and the high-temperature oxidation resistance and interface bonding strength of metal ceramic are enhanced.

The invention provides a plasma spraying high-temperature-erosion-resistant coating and a coating preparation method, and relates to the technical field of material surface treatment. Comprising the following components in parts by mass: 30-45 parts of tungsten carbide, 15-25 parts of chromium carbide-nickel-chromium alloy, 15-25 parts of yttria-stabilized zirconia, 5-10 parts of aluminum oxide-titanium dioxide composite ceramic, 10-20 parts of nickel-chromium-aluminum-yttrium alloy, 1-3 parts of nano aluminum oxide and 1-3 parts of lanthanum oxide. Multiphase collaborative design is adopted, tungsten carbide and chromium carbide-nickel-chromium alloy form double hard phases, the hardness is higher, aluminum oxide-titanium dioxide composite ceramic fills pores and improves compactness, rare earth and nanometer are adopted to cooperate, lanthanum oxide and nanometer aluminum oxide react to generate a LaAlO3 protective layer, oxidation weight gain is small, oxygen diffusion is inhibited, nanometer aluminum oxide refines grains, and the hardness is higher. In conclusion, the high-temperature oxidation resistance is high, and the erosion rate is low.

The invention relates to an additive capable of improving oxidation resistance of an ultrathin copper foil and a copper foil produced by the additive. The additive comprises ytterbium ions, butylated hydroxytoluene, polyethylene glycol and a brightener. The additive is simple in formula, the number of contained components is small, the process is easy to control, the additive is added into electrolyte to electrolyze the copper foil, and it can be achieved that the 6-micron ultrathin copper foil is free of oxidation discoloration after being placed for 120 h at the temperature of 85 DEG C and the relative humidity of 85% and free of oxidation discoloration after being baked for 60 min at the temperature of 230 DEG C.

The medium-temperature radial forging method comprises the steps that pretreatment is conducted, specifically, a niobium-tungsten alloy extrusion bar blank is heated for 60-180 minutes at the temperature of 750-950 DEG C, rapid forging and straightening are conducted, and a medium-temperature radial forging bar blank is obtained and annealed for 60-120 minutes at the temperature of 1250-1450 DEG C; medium-temperature radial forging is conducted, specifically, a two-step method is adopted, in the first step, a bar blank is preheated to 80-100 DEG C and coated with Ta1350 high-temperature glass powder, heat preservation is conducted for 90-180 minutes at the temperature of 1050-1150 DEG C, and the bar blank is forged into a bar with the diameter of 70 + / -1 mm in the mode that the diameter is reduced by 7-10 mm every time; and in the second step, the heating and coating processes are repeated, the diameter is reduced by 5-7 mm every time, and the bar with the required specification is manufactured. By optimizing the medium-temperature forging and annealing process, the fine grain structure is controlled, the high-temperature mechanical property, creep resistance and oxidation resistance of the material are improved, and the material is suitable for aerospace engines and other high-temperature and high-pressure scenes. Compared with a traditional method, the technology improves the yield, shortens the production period, reduces the labor intensity, is suitable for large-scale production, reduces surface air suction, oxidation and burning loss, and improves the production efficiency and the finished product quality.

The invention relates to the technical field of coated cutting tools, and provides a nano multilayer structure coated cutting tool and a preparation method thereof.The nano multilayer structure coated cutting tool comprises a base body and a nano multilayer structure coating deposited on the surface of the base body through a physical vapor deposition method, and the coating sequentially comprises a WC coating deposited on the base body, a WC coating deposited on the surface of the base body, a WC coating deposited on the surface of the base body and a WC coating deposited on the surface of the base The first CrCN / WC functional layer is composed of a first CrCN nano layer and a first WC nano layer which are alternately deposited; the second CrCN / WC functional layer is composed of a second CrCN nano layer and a second WC nano layer which are alternately deposited; the CrTaHfCN / CrCN / WC functional layer is formed by periodically and repeatedly depositing a first CrTaHfCN nano layer, a third CrCN nano layer and a third WC layer according to an ABC sequence; and a CrTaHfCN surface layer. According to the invention, the bonding strength between the layers is improved, and the oxidation resistance, high temperature resistance, wear resistance and crack propagation resistance of the coating are obviously improved.

The invention relates to the technical field of surface protective coatings, in particular to a preparation method of a diffusion coating based on rare earth oxide modification, which comprises the steps of matrix pretreatment, permeation agent preparation and coating preparation. The permeation agent is composed of an aluminum supply agent, a filling agent, an activating agent and a permeation accelerating agent, wherein nano cerium oxide serves as the permeation accelerating agent and can remarkably improve the coating performance. By optimizing process parameters, the aluminizing temperature is reduced to 630 DEG C, and the time is shortened to be within 5 hours. The oxidation resistance, the hot corrosion resistance and the matrix bonding strength of the coating can be remarkably improved, and the coating is suitable for TiAl intermetallic compounds and other high-temperature alloy materials and has wide application prospects in the fields of aerospace and the like.

The invention relates to the technical field of heat-resistant materials, in particular to a heat-resistant polyethylene material and a preparation method thereof, and the heat-resistant polyethylene material comprises the following raw materials: ultra-high molecular weight polyethylene, zirconium oxide-zinc aluminate spinel (ZrO2-ZnAl2O4), modified graphdiyne, an antioxidant, a heat stabilizer, a plasticizer, a flame retardant and an anti-ultraviolet agent. The ultrahigh molecular weight polyethylene, the ZrO2-ZnAl2O4 and the modified graphdiyne play a role through a synergistic effect, a polyethylene molecular chain forms a firm three-dimensional network structure in a high-temperature radiation process, and a stable matrix supporting effect is provided; the excellent chemical stability and oxidation resistance of ZrO2-ZnAl2O4 in a high-temperature environment effectively inhibit the thermal degradation reaction of polyethylene, the service life of the material is prolonged, the modified graphdiyne is beneficial to rapid heat transmission, the thermal stability of the material is improved, meanwhile, the layered structure of the material has good lubricating performance, and the service life of the material is prolonged. The modified graphdiyne and the ZrO2-ZnAl2O4 are combined to avoid heat accumulation and material aging caused by the friction effect, and the ultrahigh molecular weight crosslinked polyethylene, the ZrO2-ZnAl2O4 and the modified graphdiyne form a multi-layer protection system to jointly improve the heat stability of the material.

The invention relates to the technical field of deposition of wear-resistant and corrosion-resistant coating materials on metal surfaces, in particular to a high-toughness CrNbZrNiSiBN high-entropy nitride coating and a preparation method thereof. A bonding layer formed by a Cr layer, a transition layer formed by a CrN layer and a functional layer coated with CrNbZrNiSiBN high-entropy nitride are sequentially arranged on the surface of a base material. And the total thickness of the coated functional layer is 2-10 microns. The method is completed by adopting an ion beam assisted arc ion plating technology, and the prepared composite coating has the advantages of relatively high hardness, relatively good toughness, wear resistance, corrosion resistance, high-temperature oxidation resistance and the like. The coating can be used for strengthening and protecting the surfaces of cutters, molds, aerospace, marine ship parts and the like.

The invention provides a silicified graphite material, a silicified graphite casting mold and a preparation method of the silicified graphite casting mold, and relates to the technical field of nickel-based high-temperature alloy and titanium alloy casting. The silicified graphite material provided by the invention comprises a porous graphite matrix and a silicon carbide layer wrapping the surface of the porous graphite matrix, the porous graphite substrate has a hierarchical porous structure, the hierarchical porous structure comprises closed holes and penetrating holes, the aperture of the closed holes is 0.001-0.05 mm, the penetrating holes penetrate through the porous graphite substrate, and the penetrating holes comprise first-level penetrating holes with the aperture of 0.03-0.2 mm and second-level penetrating holes with the aperture of 0.1-1 mm; and the silicon carbide layer uniformly wraps the external surface of the hierarchical porous graphite matrix and the surfaces of the internal through holes. The silicified graphite material not only has good thermal stability and thermal conductivity, but also has good high-temperature oxidation resistance, good corrosion resistance, high mechanical strength, excellent air permeability and good dimensional stability.

The invention relates to a preparation method of a refractory material, in particular to a preparation method of a high-corrosion-resistance low-carbon magnesia-carbon refractory material. The high-corrosion-resistance low-carbon magnesia-carbon refractory material is prepared from fused magnesite aggregate, fused magnesite fine powder, Ti3SiC2 powder, crystalline flake graphite, corundum slag and phenolic resin. The prepared low-carbon magnesia-carbon refractory material has excellent oxidation resistance and slag corrosion resistance, the service life of the magnesia-carbon refractory material under the large scrap ratio smelting condition can be prolonged, and the cost is reduced from the perspective of refractory raw materials, so that the low-carbon magnesia-carbon refractory material has high economic benefits, meanwhile, the carbon content of the refractory material is lower, and the cost is lower. And high-temperature industrial carbon emission can be reduced. The oxidation index of the magnesia-carbon refractory material is 20-30% after the magnesia-carbon refractory material is oxidized in an air atmosphere of 1600-1700 DEG C for 2-5 h; and after the magnesia-carbon refractory material is eroded for 1-3 hours under the dynamic slag condition of 1600-1700 DEG C, the erosion index of the magnesia-carbon refractory material is 0.5-4%.

The invention relates to the field of building materials, in particular to nano-silver solder paste with high welding strength and a preparation method of the nano-silver solder paste. The nano-silver tin paste with high welding strength comprises the following raw materials: nano-silver powder, nano-tin powder, composite resin, a dispersing agent, an activating agent, a film-forming agent, a thixotropic agent, silicon-titanium particles, a stabilizing agent and the like. According to the nano-silver solder paste with the high welding strength and the preparation method thereof, uniform dispersion of an internal system is achieved, the welding effect and the welding performance are further optimized, the oxidation resistance can be greatly improved, the probability that high surface energy of nano-silver is prone to being oxidized to generate silver oxide is greatly reduced, and the welding quality of the nano-silver solder paste is improved. The silver solder paste prepared by the method further balances the balance between the preparation process and the high strength of the silver solder paste, and has excellent stability and mechanical strength, thereby meeting the requirements of high-reliability packaging in the prior art, and having wide application potential.

The invention provides a method for preparing a zirconium boride ceramic material through pressureless sintering, and belongs to the technical field of zirconium boride ceramics. The method comprises the steps of preparing zirconium boride composite powder, modifying silicon carbide nanowires and mixing and sintering. The method for modifying the silicon carbide nanowire comprises the steps of acid treatment and modification, the modification step comprises the following steps: adding aluminum isopropoxide into absolute ethyl alcohol, adding a nitric acid solution, stirring for 1.5-2.0 hours at the temperature of 60-63 DEG C, adding the acid-treated silicon carbide nanowire, carrying out ultrasonic dispersion and water bath evaporation, then drying, putting into a muffle furnace, and carrying out heat preservation for 2.0-2.2 hours at the temperature of 490-500 DEG C to obtain a modified silicon carbide nanowire; the ceramic material prepared by adopting the method disclosed by the invention is high in density, good in mechanical property and excellent in high-temperature oxidation resistance and stability in a complex environment.

An austenitic Fe—Ni—Cr alloy has superior oxidation resistance even under extreme high temperatures and includes, in mass %: C: 0.004 to 0.13%, Si: 0.15 to 1.0%, Mn: 0.03 to 2.0%, P:≤0.040%, S:≤0.003%, Ni: 20.0 to 38.0%, Cr: 18.0 to 28.0%, Mo:≤1.0%, Cu:≤1.0%, N:≤0.03%, B:≤0.01%, Al: 0.10 to 1.0%, at least one of Ti: 0.10 to 1.0% and Zr: 0.01 to 0.6%, O: 0.0002 to 0.0030%, Ca:<0.002%, total weight of one or more from La, Ce, and Y: 0.001 to 0.010%, Fe as a remainder and inevitable impurities, and wherein the chemical composition satisfies formulae (1) and (2): 85≥0.3×Si+1.5×Ni+1.3×Cr+5.8×Al+7.7×Zr +2.7×Ti+2173×REM −3582×S ×32.9×Mo -2448×B≥47 . . . (1) 40≥0.6×Si+1.3×Cr +23.53×Al+5.88×Ti+3074×REM −5067×S −0.8×Mn −816×N≥. . . (2), and each element symbols indicates content of each element.

The invention discloses high-conductivity low-temperature sintering composite copper paste and a preparation method and application thereof, and belongs to the technical field of conductive paste. The composite copper paste consists of the following components in percentage by mass: 70-90% of a conductive phase, 2-10% of a binding phase and the balance of an organic carrier. Wherein the conductive phase comprises cuprous hydride modified copper powder and a copper complex; the copper complex is formed by a copper compound and an organic ligand through a coordination reaction. The copper paste can be sintered to form an electrode or a circuit in a nitrogen atmosphere at a temperature of less than or equal to 300 DEG C, and has the advantages of low resistivity, good oxidation resistance, strong adhesion and the like, and the cost of the copper paste is obviously lower than that of silver paste. The invention also provides a preparation method of the composite copper paste and an application of the composite copper paste in preparation of an electronic component electrode or a conductive circuit.

The invention discloses hollow silver-coated copper particles and a preparation method and application thereof, and belongs to the technical field of conductive material preparation. Through the unique hollow silver-coated copper particle structure design and the optimized preparation method, the use amount of silver is effectively reduced, and the cost is reduced; meanwhile, the compact silver layer and the surface modification layer can achieve a synergistic effect, so that the oxidation resistance, the conductivity and the dispersity of the hollow silver-coated copper particles are remarkably improved, the hollow silver-coated copper particles have more excellent application performance, the prepared conductive paste is endowed with excellent performance, and the conductive paste is suitable for various curing modes and has good application prospects. The method has a wide application prospect in the fields of photovoltaics, flexible electronics and the like, and is suitable for large-scale production.

The application belongs to the technical field of welding materials, and discloses a preformed soldering sheet and a preparation method thereof, the preparation method comprising: a flux preparation method, wherein benocyclobutene resin, a thixotropic agent, an active agent, a surfactant, an antioxidant, a corrosion inhibitor and a solvent are weighed, mixed and heated and stirred to mix, and then cooled to obtain the required flux; a processing method of a preformed soldering sheet body soldering strip, wherein lead-free filler metal is melted at high temperature to form a soldering strip; and a preformed soldering sheet preparation method, wherein the soldering strip is uniformly coated with the flux by a coating machine, and the flux is cured and attached to the soldering strip after baking; the preformed soldering sheet is obtained by the above preparation method. The application realizes improved welding quality of the soldering sheet coated with the flux film and solder metal oxidation resistance, and the preformed soldering sheet has high stability, good wettability and good weldability, and can meet the requirements of the market for the use of the preformed soldering sheet with low cavities.

The invention provides a preparation method of silver-coated copper powder, and relates to the technical field of metal materials, the preparation method comprises the following steps: simultaneously dropwise adding a first silver-ammonia solution and a first reducing agent solution into a dispersion liquid of deoiled and activated spherical copper powder, reacting for 5-20 minutes after dropwise adding is finished, then simultaneously dropwise adding a second silver-ammonia solution and a second reducing agent solution, and reacting for 5-20 minutes after the reaction is finished; and reacting for 25-40 minutes, filtering, washing with water, and drying to obtain the silver-coated copper powder. The concentration of the first silver-ammonia solution is higher than that of the second silver-ammonia solution. The silver-coated copper powder obtained through the preparation method is good in particle regularity and size uniformity, few in agglomeration phenomenon, good in oxidation resistance and low in resistivity.

The invention discloses a hard coating with thermal stability and high-temperature oxidation resistance as well as a preparation method and application of the hard coating, and belongs to the technical field of nitride hard coatings. The hard coating is composed of a bottom columnar crystal TiAlN base coat, a middle columnar crystal AlTiCrN middle layer and an AlCrSiBN surface layer of a surface nanometer composite structure. Low-aluminum TiAl target deposition is adopted for the TiAlN base layer, high-aluminum AlTi target and AlCr target co-deposition is adopted for the middle of the TiAlN base layer, and high-aluminum AlCrSiB target deposition is adopted for the AlCrSiBN surface layer; the thickness of the TiAlN base coat is 0.1 to 0.5 [mu] m; the thickness of the AlTiCrN intermediate layer is 1.0 to 2.0 [mu] m; and the thickness of the AlCrSiBN surface layer is 0.05 to 0.2 [mu] m. The coating has high film-substrate binding force, thermal stability and high-temperature oxidation resistance. The inner layer of the coating has excellent thermal stability, and the outer layer of the coating has excellent high-temperature oxidation resistance, so that the coating has wide application prospects on the surfaces of products such as cutting tools and molds.

The embodiment of the invention relates to the technical field of pipe testing, and discloses a pipe oxidation resistance testing system which comprises an oxidation resistance testing device. The oxidation resistance testing device comprises a first box body, a second box body, a water pump device and a testing assembly, the water pump device is arranged in the first box body, the testing assembly is arranged in the second box body, and the first box body and the second box body are arranged in a split mode. The testing assembly comprises a liquid storage tank, a heat preservation unit and a sample tube testing unit, the heat preservation unit is used for conducting heat preservation on the sample tube testing unit, and the sample tube testing unit comprises a connecting pipeline and testing clamps arranged at all testing points on the connecting pipeline; the test fixture is used for clamping the corresponding sample test tube and enabling the sample test tube to be communicated with the connecting pipeline. The test system provided by the embodiment of the invention adopts a module combination box type damping design, and is simple in overall structure, high in integration level and small in single occupied area. The split type design can effectively avoid the influence of motor vibration on the service life of the pipe in the testing process.

The invention discloses a barium titanate coated Ni particle material synthesized under the assistance of a spray drying technology and a method thereof, and belongs to the technical field of metal powder material preparation. The method comprises the following steps: firstly, taking metatitanic acid and barium hydroxide as raw materials, and mixing the metatitanic acid and the barium hydroxide with nano and submicron Ni powder to prepare a mixed solution; secondly, synthesizing a Ni-based composite material intermediate by adopting a spray drying method; and finally, sintering in a tubular furnace to form the barium titanate coated Ni powder. The barium titanate coated Ni inner electrode material is Ni coated BaTiO3 spherical particles with a core-shell structure, the particles are of a core / shell microstructure, a shell layer is a barium titanate coating layer with the thickness of 10-15 nm, and the particle size of the particles is 100-150 nm. According to the method, required equipment can be scaled, components and microstructures are easy to regulate and control, and the method has high sphericity and dispersity, high compactness and good repeatability; the particle size and distribution can be changed by adjusting process parameters; meanwhile, good interface bonding with a ceramic dielectric layer is realized, and the key problems of mismatching of interlayer interface volume shrinkage, easy cracking and the like in the sintering process are relieved.