260 results about "Solderability" patented technology

The invention belongs to the field of rail manufacturing, and specifically discloses a manufacturing method for improving the low temperature fracture resistance and contact fatigue damage resistance of rails and the rails obtained thereby. The method comprises the following steps: converter smelting, LF refining, RH vacuum treatment, billet continuous casting, billet cleaning and cooling, billet heating, rail rolling, online heat treatment and post-treatment, wherein: during the converter smelting process, bottom blowing of nitrogen is performed; after the RH vacuum treatment, iron-calcium wire feeding treatment is performed. Calculated by mass percentage, the chemical composition of the steel billet includes: C: 0.50-0.65%, Si: 0.45-0.95%, Mn: 0.35-0.85%, Cr: 030-0.80%, Cu: 0.20-0.55%, Ni: 0.10-0.30%, N: 0.007-0.030%, and the chemical composition of the steel billet also includes at least one of V, Nb, and Ti, wherein V: 0.02-0.15%, Ti: 0.001-0.030%, Nb: 0.01-0.08%, and the rest is Fe and unavoidable impurities. The steel rail obtained by the method provided by the present invention has excellent comprehensive properties such as resistance to low-temperature fracture, resistance to contact fatigue, corrosion resistance and weldability.

The invention discloses a solar cell with alloy as a flexible substrate and a preparation method thereof, a kovar alloy sheet is used as the flexible substrate to be bonded with an epitaxial layer, the coefficient of thermal expansion of the kovar alloy sheet is similar to that of an epitaxial material, and dark cracks of the epitaxial layer caused by cold and hot temperature difference are avoided; moreover, the metal bonding layer adopts a thick-silver thin-gold structure taking silver as a substrate, so that the production cost is greatly reduced, and the weldability of the back electrode is enhanced; and the back electrode also adopts a thick silver and thin gold structure taking silver as a substrate, so that the front warping of the Kovar alloy sheet can be balanced, the weldability of the back electrode is enhanced, the drawing force of the back electrode is improved, the thin gold plated on the thick silver can also prevent silver oxidation and resist the impact of atomic oxygen, and the service life of the solar cell is prolonged.

The invention provides a packaging structure, a manufacturing method thereof and an electronic device adopting the packaging structure. The manufacturing method comprises the following steps: firstly, covering a pre-covering metal layer on the bottom surface of an initial pin, and then carrying out half cutting on the initial pin to form a pin with a stepped cutting groove, so that a base material of the pin is exposed at the stepped cutting groove of the pin; then the surface of the stepped cutting groove is selectively covered with an organic solderable protection layer to prevent the surface of the stepped cutting groove of the pin from being oxidized, so that when the packaging structure is welded with other devices, welding flux can be welded at the stepped cutting groove, 100% optical inspection can be conveniently carried out from the side face of the packaging structure, the integrity of welding spot connection is verified, and the reliability of the packaging structure is improved. The purpose of verifying electrical connection is achieved. According to the manufacturing method, the surface of the stepped cutting groove of the pin is protected only through selective covering of the organic solderable protection layer, an electroplating process does not need to be executed, the manufacturing cost is greatly reduced, and environmental pollution cannot be caused.

The invention discloses a halogen-free low-splashing environment-friendly solder wire and a preparation method thereof, and relates to the technical field of electronic welding materials, and the halogen-free low-splashing environment-friendly solder wire is prepared from the following raw materials in percentage by mass: 1-4wt% of halogen-free scaling powder and the balance of lead-free solder; the lead-free solder is composed of the following components of Cu, Bi, Al, Ga, Ir, Ca, In and Sn. The halogen-free scaling powder comprises the following components: (3, 6-diamino acridine-9-yl) boric acid, glycerol triabietate, 3-(N-morpholinyl)-2-hydroxy propanesulfonic acid sodium salt, 3-trihydroxymethyl methylamino-2-hydroxy propanesulfonic acid, hexahydro-1, 3-ethoxy-s-triazine, a functional copolymer, a surface active agent, a corrosion inhibitor, a halogen-free activity reinforcing agent, an antioxidant, a solvent and rosin resin. The solder wire is low in splashing rate, high in surface resistivity and welding spot reliability, free of obvious corrosivity and good in weldability.

The invention discloses a fabricated steel-UHPC external prestressing combined box girder and a construction method and application thereof, and relates to the technical field of bridge engineering, the fabricated steel-UHPC external prestressing combined box girder comprises a prefabricated steel-UHPC combined top plate, a prefabricated steel-UHPC combined bottom plate, a prefabricated steel-UHPC combined web plate, a steel diaphragm plate and an external prestressing system. The box girders are formed by combining prefabricated slabs, the prefabricated web plates are firmly connected with the prefabricated top plate and the prefabricated bottom plate through welded steel plates and post-poured UHPC, and arrangement and tensioning of external prestress are achieved by arranging steel anchor boxes and steering gears in box chambers. According to the combined box girder, the steel and the UHPC are combined to form a structural form that the steel plate is wrapped by the UHPC, and the advantages of high strength, high durability, high toughness, high compactness, low creep and the like of the UHPC and the advantages of high strength, high elastic modulus and weldability of steel are fully utilized, so that the box girder has the advantages of being excellent in structural stress performance, light in overall weight, good in durability, small in later-stage deformation, low in cost and the like. And the hoisting device is especially suitable for bridges in urban rail transit or urban railways.

The invention discloses a hot-dip tinning copper plate strip capable of reducing the surface friction coefficient of a copper strip and a manufacturing method of the hot-dip tinning copper plate strip, relates to the field of hot-dip tinning of copper plate strips, and aims to solve the problem that a product cannot have high hardness and good weldability and corrosion resistance at the same time in the prior art. The method comprises the following steps: plating a pure tin layer on the surface of a copper plate strip in a hot dipping manner, cooling to room temperature, annealing, and preserving heat, so that a Cu6Sn5 layer grows between the copper plate strip and the pure tin layer until the Cu6Sn5 layer grows to occupy more than half of the overall thickness of the plating layer, thereby improving the hardness of the tin plating layer of the copper plate strip. Therefore, the hot-dip tin-plated copper plate strip has high hardness and good weldability and corrosion resistance, and the pure tin layer on the outermost layer can enable the copper plate strip to have low friction coefficient and low insertion and extraction rate and can be used for multi-piece insertion.

The invention relates to an aluminum alloy material and a preparation method thereof.The aluminum alloy material comprises Mn, Si, Fe, Cr, a first component, rare earth and Al, and the first component comprises at least one of Ti, B, Zr, V and Be; according to the total mass of the aluminum alloy material being 100%, Mn is smaller than or equal to 4%, Si is smaller than or equal to 3%, Fe is smaller than or equal to 3.5%, Cr is smaller than or equal to 6%, the mass fraction of the first component is 1%-2%, and the mass fraction of the rare earth is 7%-12%. The aluminum alloy material provided by the invention has excellent solderability, die-casting property and corrosion resistance, and can meet the requirements of complex part manufacturing and high-reliability connection.

The invention belongs to the technical field of precious metal electronic paste, and particularly relates to a preparation method and application of submicron spherical gold-platinum-palladium alloy powder used for being matched with low-temperature co-fired ceramics. The preparation method comprises the following steps: mixing a tetrachloroauric acid solution, a hexachloroplatinic acid solution and a tetrachloropalladium (II) acid solution to obtain a gold-platinum-palladium mixed solution; the gold-platinum-palladium mixed solution, the dispersing agent solution and the modified reducing agent solution are mixed for a second time, after a reduction reaction is conducted, static settlement and solid-liquid separation are conducted in sequence, obtained solids are washed and dried in sequence, and the obtained submicron spherical gold-platinum-palladium alloy powder used for being matched with the low-temperature co-fired ceramic has the advantages of being uniform in particle size, free of agglomeration, high in dispersity and the like. After low-temperature co-firing with a ceramic substrate, the substrate has the characteristics of flatness, no bubble, excellent weldability and soldering resistance, good batch stability and the like.

The invention discloses a flux-cored wire with high crack resistance and wear resistance and a preparation method of the flux-cored wire. The flux-cored wire comprises the following flux-cored raw materials in percentage by mass: 6-10% of electrolytic manganese; 28 to 34% of metal chromium; 0.5 to 1.5 percent of ferrotitanium; 1-4% of tungsten powder; 5-9% of nickel powder; 4-8% of 45 # ferrosilicon; 8 to 12% of colloidal graphene; 8-12% of molybdenum powder; and the balance of iron powder. According to the flux-cored wire, C, W, Cr, Mo and other elements are added into the flux core, the proportion of flux core powder is reasonably adjusted, and the flux-cored wire is suitable for surfacing continuous casting rollers, hot rolling rollers, shafts with the working temperature lower than 510 DEG C and sealing faces of medium-temperature and high-pressure stop valves and has the advantages of being high in heap melting speed, good in weldability, high in surface abrasion resistance, low in cost and the like. The hardness value of the steel plate can basically reach 50 HRC, and the steel plate has good crack resistance.

The present invention discloses a solderability testing mechanism, comprising: a test table, a soldering trough and a solder pot located on the test table, a liquid level sensor and a solder height sensor located on the side of the solder pot; the liquid level sensor is used to measure the liquid level of the solder pot, and the solder height sensor is used to measure the height of the position to be soldered in the workpiece; a mobile module located above the test table, the mobile module being provided with a fixed clamp for clamping the workpiece; and a controller communicatively connected to the liquid level sensor, the solder height sensor, and the mobile module. The present invention provides a solderability testing mechanism and method that can accurately control the depth of tin immersion in a workpiece, thereby standardizing solderability testing standards and improving the accuracy of solderability testing.

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 relates to the technical field of aero-engine maintenance, in particular to a high-aluminum-titanium cast high-temperature alloy welding repair method which aims at solving the problems that the aluminum-titanium content is larger than or equal to 9%, gamma phase enhanced cast high-temperature alloy is poor in welding performance, and the welding repair qualification rate is low due to the fact that hot cracks are likely to be generated. Firstly, a bench worker is used for polishing a U-shaped groove to remove cracks, then a low-aluminum-titanium layer is formed on the surface of a to-be-welded area through a pulse high-activity high-temperature bond separation reaction technology so as to improve weldability of a part, then a low-heat-input TIG welding technology is adopted for surfacing repair, the one-time welding qualification rate can reach 75% or above, the room-temperature strength of a weld joint reaches 95% or above of a base material, and the welding quality is improved. The high-temperature tensile strength reaches more than 60% of that of a base material, the fatigue strength is high, and the method has the advantages of simplicity and convenience in operation, no need of special preheating and slow cooling, high efficiency, low cost and the like, is suitable for various workpieces with complex structures, and is easy to realize batch processing.

The utility model relates to a welding structure at the joint of a thin-wall part and a thick-wall plate, which comprises the thin-wall part and the thick-wall plate, and is structurally characterized in that the thin-wall part is provided with a multi-layer fitting structure, and the weldability, the joint strength, the fatigue life and the corrosion resistance of the thin-wall part are improved through the multi-layer fitting structure. The utility model provides a plurality of implementation schemes provided with a plurality of layers of fitting structures, which are applied to the manufacturing of the stainless steel corrugated compensator, can greatly improve the weldability of the welding of the thin-wall corrugated pipe and the thick-wall end cover plate, prolong the fatigue life of the corrugated pipe at the welding part and improve the corrosion resistance of the joint, and is easy to realize automatic welding. The scheme is low in overall cost, high in efficiency, simple in process and good in reliability, the current ultrathin plate welding problem can be solved, huge economic benefits are generated, the product quality is greatly improved, and the product service life is greatly prolonged.

The invention discloses rosin type soldering flux for indium-based low-temperature soldering paste and a preparation method of the rosin type soldering flux, and belongs to the technical field of brazing soldering flux. The soldering flux is prepared from the following components in percentage by weight: 40 to 60 percent of modified rosin, 2 to 5 percent of an organic acid activating agent, 0.5 to 2 percent of a halogen-containing compound, 2 to 5 percent of hydrogenated castor oil, 0.1 to 1 percent of benzotriazole, 0.1 to 1 percent of triethanolamine, 0.5 to 2 percent of a surfactant and 0.5 to 2 percent of paraffin oil. And the balance of an organic solvent. The method has the advantages that the prepared soldering flux is good in wettability and excellent in weldability, welding spots are bright and full, the welding void rate is as low as 2.4%, the heat conductivity can reach 43.12 W / mK, the welding spot shear strength can reach 13.45 MPa, and the soldering flux is suitable for low-temperature welding of indium-based brazing filler metal.

Provided is an aluminum coated steel sheet having excellent anti-corrosion properties and weldability, and a manufacturing method thereof. The aluminum coated steel sheet includes: an austenitic base steel sheet including at least 70 area % of an austenite microstructure; and an aluminum coating layer formed on the base steel sheet, wherein the base steel sheet includes at least 80 area % of ferrite in a surface layer portion, which denotes a region extending from the interface with the coating layer to a depth of 100 μm into the base steel sheet, and the aluminum coating layer may have a composition comprising 2-12 wt % of Si, 5-30 wt % of Zn, and 0.1-5 wt % of Mn, with the balance being Al and inevitable impurities.

The utility model discloses a capacitor service life test clamp, and relates to the technical field of capacitor detection, the capacitor service life test clamp comprises a clamping box with one end provided with an opening, a clamping structure is arranged in the clamping box, and four corners of the upper and lower surfaces of the clamping box are fixedly connected with connecting rods. Through cooperative arrangement of the clamping box, the first clamping hole, the clamping plate, the second clamping hole, a spring and other structures, during use, the clamping plate is pushed to enable the first clamping hole and the second clamping hole to be aligned, the middle section of the capacitor penetrates through the first clamping hole and the second clamping hole, the clamping plate is loosened, the clamping plate moves under the action of the elastic force of the spring, and the capacitor is clamped. The inner walls of the first clamping hole and the second clamping hole clamp the capacitor from the two sides, the end of the capacitor is not subjected to clamping acting force, and it is avoided as much as possible that when a traditional test clamp fixes the capacitor, certain pressure is applied to the two ends of the capacitor, oxidation or falling off of a tin coating at the end of the capacitor is likely to be accelerated, weldability of the capacitor is reduced, and the service life of the capacitor is prolonged. And the reliability of the capacitor is influenced.

The invention provides dual-phase steel, a preparation method of the dual-phase steel and a vehicle applying the dual-phase steel. The dual-phase steel comprises the following element components in percentage by mass: 0.07 to 0.10 percent of C, 0.6 to 0.8 percent of Si, 1.8 to 2.1 percent of Mn, 0.018 to 0.022 percent of Cr, 0.015 to 0.025 percent of Ti, 0.02 to 0.05 percent of Al and the balance of Fe and inevitable impurities. One component of the dual-phase steel can achieve different strength grades, the tensile strength of the dual-phase steel covers the strength grade range of 590-1180 MPa, the strength requirements of all parts of a body-in-white can be met, the carbon equivalent and the cost of the dual-phase steel are low, the weldability and the welding quality between body-in-white plate combinations can be improved, the body-in-white production process is simplified, and the production efficiency is improved.

The invention relates to a filling material for 6XXX series aluminum alloy and a welding process of the filling material, and belongs to the technical field of aluminum alloy. The filling material comprises the following elements in percentage by mass: 0.5 to 2.00 percent of Si, 0.80 to 2.00 percent of Mg, 0.20 to 3.00 percent of Cu, 0.20 to 0.50 percent of Cr, 0.50 to 0.80 percent of Mn, 0 to 0.10 percent of Ti, 0.15 to 2.00 percent of Zn, 0 to 0.15 percent of Fe and the balance of Al and other inevitable impurities, and the total impurities are 0 to 0.15 percent. The filling material has good weldability, promotes a precipitation strengthening mechanism, has the same strengthening element composition as a 6XXX series aluminum alloy base material, can be applied to welding of the 6XXX series aluminum alloy in multiple welding modes, reduces dilution of weld joint strengthening elements, and can effectively improve the mechanical properties of a joint weld joint and a heat affected zone at the same time.

The invention relates to the technical field of centrifugal pump production, in particular to a welding device for centrifugal pump production, which comprises a welding table, a heat conduction air bag, a knocking assembly and an auxiliary feeding assembly, a plasma arc welding gun is mounted on the welding table through a mechanical arm, and the welding device further comprises a heat conduction air bag, a knocking assembly and an auxiliary feeding assembly, an air bag groove is formed in the side wall of the blade inserting groove, heating plates are arranged at the bottom end and the inner side wall of the air bag groove, and the knocking assembly is used for hammering a welding seam in the process that the plasma arc welding gun moves and welds the blade and the blade disc according to the auxiliary groove; the heat conduction air bag and the like are arranged, carbon dioxide which expands after being heated is arranged in the heat conduction air bag, after the carbon dioxide is heated, the volume expands, the heat conduction air bag can be attached to the to-be-welded blade, the carbon dioxide with the temperature guides heat to the blade through the heat conduction air bag, the blade can be preheated, the weldability of the blade is improved, and cracks are reduced.

The present invention proposes a deoxidation tool and a deoxidation method for the pins of a ceramic array package device, wherein the deoxidation tool comprises a limiting base, a first protective cover plate and a drainage cover plate; a card slot for limiting the ceramic array package device is provided on the limiting base; the first protective cover plate is located above the limiting base, and a first array of micropores is provided thereon to allow and cooperate with the pins of the ceramic array package device to pass through; the drainage cover plate is located above the first protective cover plate, and a processing groove corresponding to the first array of micropores is provided on the drainage cover plate, and the processing groove forms an abrasive flow inlet and outlet channel above the first protective cover plate. By designing the above-mentioned deoxidation tool to protect the non-oxidized area of ​​the ceramic array package device, and then using the abrasive flow to deoxidize the to-be-processed welding end of the pins of the ceramic array package device, the deoxidation treatment of the pins of the ceramic array package device can be achieved without causing any damage to the ceramic array package device, thereby improving the weldability of the packaged device.

The invention relates to the technical field of radar electronic equipment antenna feeder subsystem manufacturing, in particular to a method for assembling a microminiature radio frequency connector on a high-density antenna array plane, which comprises the following steps of: S1, manufacturing a light antenna reflecting plate with step through holes uniformly distributed on the surface and weldable plating layers pre-plated in the holes; s2, manufacturing a metalized tapered slot Vivaldi obliquely polarized antenna unit with a blind hole and a weldable coating pre-plated in the hole; s3, a welding tool which is provided with an elastic device and has a shape maintaining function is manufactured; s4, designing a special solder ring pre-coated with a soldering flux; and S5, welding a microminiature radio frequency connector on the reflecting plate, and simultaneously realizing high-quality interconnection of the connector and the antenna array through one-time welding, thereby solving the problems of array surface deformation and poor welding in the process of assembling the microminiature (SMP / SSMP) radio frequency connector on the existing antenna array surface.

The invention discloses a titanium alloy with high strength, high plasticity and toughness and a weldable structure. The titanium alloy is a Ti-Al-Mo-V-Cr-Zr series beta-rich type two-phase titanium alloy. According to the titanium alloy, the composition of the titanium alloy is controlled, the synergistic effect of high-strength contribution of Al and Mo, plasticity and toughness guarantee of V and Nb, structure optimization of Cr and Zr and low-oxygen cleanliness control is exerted, the multi-performance balanced type high-strength, high-plasticity and high-toughness weldable structure titanium alloy is obtained, and after heat treatment, the tensile strength Rm of the titanium alloy is larger than or equal to 1100 MPa, the ductility A of the titanium alloy is larger than or equal to 15%, the fracture toughness KIC of the titanium alloy is larger than or equal to 80 MPa.m < 1 / 2 >, and the impact toughness KV of the titanium alloy is larger than or equal to 40 J; and the welding seam strength matching coefficient is 0.9 or above, collaborative optimization of high strength, high plasticity and toughness, weldability and environmental adaptability is achieved, and therefore the structural mass is reduced, the service life is prolonged, integrated manufacturing is facilitated, and the high-strength and high-toughness alloy is suitable for key components in the industrial field and extreme working condition engineering scenes.

The invention discloses a printed circuit board manufacturing method for improving the reliability and weldability of a buried copper block, and the method comprises the following steps: processing a depth control blind groove in a PCB core board, and processing a groove hole with a corresponding shape in a prepreg; an embedded copper block is provided, a glue flowing groove is machined in the side wall or / and the bottom of the embedded copper block, and a protective pit is machined in the welding face of the embedded copper block; a frame type carrier is provided, a plurality of positioning grooves which are distributed in an array mode and matched with the copper blocks in shape are formed in the carrier, and the copper blocks with the size smaller than 80 mm * 80 mm are correspondingly placed in the positioning grooves of the carrier to be subjected to browning treatment; laminating the core plate and the prepreg according to a design sequence, embedding the copper block into the blind groove, and ensuring that the welding surface with the protective pit faces upwards; vacuum pressing is conducted, the glue flowing groove is filled with the molten prepreg, part of the molten prepreg flows into the protective pit, and the area, except for the protective pit, of the welding face of the embedded copper block is cleaned; and drilling, copper deposition electroplating and pattern transfer are carried out. According to the manufacturing method of the printed circuit board, the problems that in the prior art, buried copper blocks are poor in combination reliability, and solderability is not guaranteed are solved.

The invention relates to an easy-to-form corrosion-resistant and wear-resistant steel plate for a conveying pipeline and a manufacturing method thereof, and belongs to the field of pipeline steel. The surface Brinell hardness of the wear-resistant steel plate is 370-430 HB, the ductility is larger than or equal to 10%, the Charpy V-shaped impact energy at the temperature of-40 DEG C is larger than or equal to 30 J, d is equal to 4 t, and no crack exists after 180-degree cold bending; the martensite structure is uniform and fine, the grain size is larger than or equal to 7 grades, and the total grade of A, B, C and D fine inclusions in the structure is smaller than or equal to 2.0. And under the working condition that the pH value is 6.0-8.5, the corrosion resistance of the steel can be improved by 40% or above compared with that of Q355 structural steel. A high-cleanliness steelmaking continuous casting process, plate blank hydrogen diffusion, two-stage controlled rolling, high-temperature normalizing pretreatment, off-line quenching and tempering are adopted, control is conducted from the aspects of chemical component design, base metal structure and the like, and the low-temperature toughness, formability, corrosion resistance and weldability of the wear-resistant steel plate for the conveying pipeline are guaranteed; and a solution is provided for the application of the long-service-life wear-resistant pipeline.

The present invention relates to a filler material for 6XXX series aluminum alloys and its welding process, belonging to the technical field of aluminum alloys. The elemental composition and its mass percentage of the filler material are as follows: Si 0.5% - 2.00%, Mg 0.80% - 2.00%, Cu 0.20% - 3.00%, Cr 0.20% - 0.50%, Mn 0.50% - 0.80%, Ti 0 - 0.10%, Zn 0.15% - 2.00%, Fe 0 - 0.15%, the balance being Al and other inevitable impurities, with a total impurity of 0 - 0.15%. This filler material has good weldability, promotes the precipitation strengthening mechanism, has the same strengthening element composition as the base metal of 6XXX series aluminum alloys, can be applied to the welding of 6XXX series aluminum alloys through various welding methods, reduces the dilution of strengthening elements in the weld, and can effectively improve the mechanical properties of the joint weld and the heat affected zone at the same time.

The invention discloses a preparation method of an organic solderable protective film, which comprises the following steps: carrying out controllable micro-etching treatment on the surface of a metal substrate, so that the arithmetic mean roughness of the surface of the metal substrate is less than or equal to 0.20 mu m, and microscopic bulges on the surface of the metal substrate are of smooth hill-shaped structures; and performing preimpregnation treatment and OSP film forming treatment on the surface of the metal substrate in sequence to form the organic weldability protective film. According to the method disclosed by the invention, the uniformity of the organic weldability protective agent film layer and the reliability of high temperature resistance and chemical corrosion resistance are improved by accurately regulating and controlling the microstructure of the copper surface.

The present invention relates to a composite welding sheet and a preparation method and application thereof. The composite welding sheet comprises a diamond-reinforced copper welding sheet, a first metal layer to a fifth metal layer sequentially arranged in a direction away from the surface of the diamond-reinforced copper welding sheet, a second metal layer and a fourth metal layer are copper layers, a third metal layer is a tin layer, and a fifth metal layer is a silver layer. The diamond-reinforced copper welding sheet is formed by mixing nano-scale copper powder, micron-scale doped modified diamond powder and titanium powder and then hot-pressing. The present invention performs doping modification on micron diamond, which can allow doped atoms to penetrate into the micron diamond lattice, improve the electrical conductivity, reduce the heating power of the welding layer, improve the thermal conductivity and thermal conductivity stability, and control the generated intermetallic compound to be the required Cu6Sn5 by controlling the thickness ratio of the second metal layer to the third metal layer and the thickness ratio of the fourth metal layer to the third metal layer, and prevent the generation of brittle Cu3Sn, thereby improving the mechanical strength and reliability of the metal-to-metal joint on the basis of achieving weldability.

The application discloses a surface treatment method for improving the weldability of aluminum alloy, which comprises the following steps: (1) alkaline degreasing: placing the aluminum alloy shell into an alkaline degreaser for cleaning; (2) etching: placing the aluminum alloy shell into an etching solution; (3) water washing: cleaning the aluminum alloy shell after etching with deionized water; (4) zinc immersion: placing the aluminum alloy shell into an alkaline zincate zinc immersion solution for immersion; (5) nickel plating: placing the aluminum alloy shell after zinc immersion into a chemical nickel tank for nickel plating; (6) after the nickel plating is completed, taking out the shell, repeating the process step (3) water washing, and then carrying out drying. Advantages: 1) the reliability of the plating layer after the aluminum alloy surface is plated is improved; 2) the cost is low, and the method is simple and easy to implement; 3) the weldability of the aluminum alloy surface is improved, the problem that the aluminum alloy and other metals are difficult to realize welding is solved, and the effect is remarkable.

The invention belongs to the technical field of printed circuit board manufacturing, and particularly relates to a chemical tin immersion method and a tin immersion solution of a PCB (printed circuit board), the method and the solution adopt a couple replacement and autocatalytic reduction dual mechanism, and a tin-bismuth alloy layer is deposited on a copper bonding pad of the PCB by introducing a reducing agent and bismuth ions. The tin immersion solution comprises divalent tin salt, an acidic component, a complexing agent, a reducing agent, bismuth salt and an antioxidant. The thickness, the compactness and the uniformity of the tin layer are effectively improved, IMC growth is inhibited, and the weldability, the oxidation resistance and the long-term reliability of the PCB bonding pad are improved.

The application discloses a rare earth high-strength dual-phase steel and a forming method and application thereof, and belongs to the technical field of dual-phase steel. The forming method of the rare earth high-strength dual-phase steel comprises the following steps: converter smelting, LF refining, RH refining, adding cerium iron and yttrium iron at the end of the RH refining or before continuous casting, continuous casting, three-stage hot rolling, cold rolling and three-stage annealing. The rare earth high-strength dual-phase steel has good cold stamping formability, high weldability, no rare earth element segregation, no cracking of steel forming, high yield, and can be directly used to prepare automobile bodies after cold stamping forming at normal temperature. There is no rare earth inclusion or coarse carbon nitride brittle bulk agglomerate on the surface layer of the weld, the rare earth element is in a dispersed distribution state, has excellent dispersion strengthening effect, the weld is not prone to cracking, and the mechanical properties of the weld are superior to those of the base material.