Aerospace solders reach figuration model technology

In recent years, as high-powered plane (airplane of military of transport of new-style opportunity for combat, large-scale for military use, special type and gunship) , aerospace is aero develop, each country government and army roll out new research plan ceaselessly, invest capital of a huge sum, developed a series of advanced aerospace to make a technology, especially advanced solder with figuration technology, include agitate friction welding to receive technology, figuration exceeding model among them / diffuse photograph of fluid of join, instantaneous diffuses join, laser is compound heat source join. Friction welding of agitate of agitate friction welding (Friction Stir Welding, FSW) it is England solders institute (TWI) invented 1991, it is the world solders time span applies to industry from the invention on technical phylogeny the shortest with development look of the quickest a solid joins new technology, made a domain receive success application in industry 1996. Agitate friction welding is the agitate head that uses a kind of special blame waste, rotating to be pressed by the interface of solder spare parts, agitate head and be made be heated quickly to produce heat build-up plasticity by solder material by the attrition of solder spare parts, when the shift before be being faced along solder abutment when agitate head, the part that produces heat build-up plasticity moves action to fall in the move coming back of agitate head by before transfer backward, press master piece to use next diffusing in forge of agitate the top of head again join forms compact solid photograph join connect. With the tradition solder methodological photograph is compared, agitate friction welding avoided the metallurgy flaw that arc solder method brings, also have the advantage with a lot of method that press solder, if solder,be out of shape small; Can solder a variety of contact type, special apply to long straight welding line; Smokeless dirt, splatter, ultraviolet radiation; Easy implementation automation. Of course the limitation that agitate friction welding also puts in it, for example, because solder when, agitate head to be brought to bear on by solder workpiece enough great upset pressure and forward driving force, the requirement is right rigid fastening be undertakinged by solder spare parts; Solder last meeting exists " ward " ; Because be to use data thermoplastic the join figuration of implementation, those who ask it is certain to be had by solder material is thermoplastic, cannot solder namely thermoplastic very poor material. In addition, compare with arc solder or photograph of resistor spot welding, wait in the robot flexible the limitation with also got certain on the application of equipment. Soldering in view of agitate friction welding the nonexistent material is fused characteristic in the process, avoid the metallurgy flaw that fusion welding method brings effectively, should solder so the skill is extraordinary apply to the high strenth aluminium alloy that solders to produce metallurgy limitation easily, agitate friction welding can solder almost the aluminium alloy material of all series and grain enhance aluminium radical composite material (Metal Matrix Composites, MMC) . The 2000 series that think that he cannot solder to using fusion welding method (Al-Cu) with 7000 series (Al-Zn) , 8000 series (Al - Li) wait for excel in aluminium alloy, used agitate friction welding to score huge success. Because this technology is fast,got applied extensively in aerospace domain. In aerospace domain comfortable the structure that solders at using FSW technology includes: The low temperature in the envelope of for military use or civil aircraft, spacecraft lights material or blank bin, the auxiliary tank of aerostat gasoline tank, warplane, for military use or science and technology explore a rocket to wait. In aviation respect, TWI and American ALCOA company undertake cooperative, GRAWFORD-SWIFT company and BAE airbus company cooperate, use agitate friction welding at medium-sized wait with large airlines structural member, envelope solder, american ECLIPSE (eclipse) airline still uses agitate friction welding to make include shape of costal region of plane envelope, ala, bowstring to prop up, the assembly of plane floor and structural member. In spaceflight respect, TWI applied this technology to produce box of fuel of space shuttle of aluminium alloy of 3 2000 series for Boeing company; Company of aerospace of Martin of · of American Losk Heed soldered with this technology space shuttle is exterior store the microtherm container of lox; Be in center of Marshall spaceflight flight, already also soldered with this technology container of large cylinder form. To heterogeneous material join, agitate friction welding also has advantage, if agitate friction welding can realize 2024/6061 and 2024/7075 not only,wait for material of different name aluminium alloy solder, still can realize the not akin material such as copper alloy and aluminium alloy solder. Agitate friction welding still can solder the alloy material such as copper, magnesian, zinc, lead, mix to steel alloy, titanium alloy the research of development of agitate friction welding of composite material already also obtained metallic radical to succeed. Figuration exceeding model / diffuse the interior with join exceeding plasticity is to show material is in certain (organization) condition (if grain appearance reachs dimension, photograph to change,wait) and exterior (environment) condition (wait like rate of temperature, meet an emergency) below, present an unusually low shedding to change fight unusually force, tall shedding metamorphic can (for example old outspread rate) phenomenon. Transcending the report with plasticity the earliest phenomenon is 1920, when the person such as Rosenhain discovers Zn-4Cu -7Al alloy bends in low speed, can curve ° of close 180. 1934, british CPPearson discovers Pb-Sn in all brilliant alloy can get the outspread rate of 2000% when drawing of room temperature low speed. The discovery such as the AABochvar of the Russia before 1945 Zn-Al eutectoid alloy has unusually high outspread rate to put forward " exceed plasticity " this one noun. 1964, american WABackofen had systematic research to Zn-Al alloy, put forward M of index of sensitivity of rate of meet an emergency to be worth this new idea, to exceed plasticity research laid a foundation. 60 time later period reachs the century on 70 time, as a result of Euramerican wait for what cruiser of developed country supersonic speed plans to drive, the use of titanium alloy material and dosage increase, the climax that exceeds plasticity research was formed on the world. Each country scholar is in exceeded the respect such as plasticity material, mechanical, mechanism, figuration to have much research, preliminary formed wholer academic system. Particularly seductive is, come nearly a few years the metal exceeded plasticity to already won relatively wide application in industrial production domain. The Zn alloy that a few exceed plasticity, Al alloy, Ti alloy, Cu alloy and black metal be out of shape with its function and material pledge exceedingly goodly wait for a characteristic equably, make in aerospace and car component production, handicraft, instrument appearance carapace overspreads a play in the production with component of a few complex form the function that cannot supersede. The breed that exceeds plasticity metal at the same time and amount also had substantially increase, besides inchoate in all outside brilliant, eutectoid metal, still have precipitation sclerosis model with advanced alloy; Besides low melting point outside Pb radical, Sn radical and famous Zn-Al eutectoid alloy, still have Mg radical, Al radical, Cu radical, Ni radical and Ti base wait for nonferrous metal and Fe base alloy (Fe-Cr-Ni, fe-Cr) , carbolic steel, low-alloy steel and cast-iron wait for black metal, gross already amounted to hundreds kinds. Besides, change super- plasticity, " advanced material " (material of the rice that be like accept, metal radical the compound between composite material, metal, pottery and porcelain) exceeded plasticity to also get very great progress. The metal exceeds plasticity to be able to get applied in a lot of domains, include forming, heat treatment, solder, cast, even the respect such as cutting treatment. In aerospace manufacturing industry, exceed plasticity craft typically -- figuration exceeding model / diffuse the effect with join compound craft already was being developed increasingly main. Figuration exceeding model (Superplasticity Forming, SPF) / diffuse join (Diffu Sion Bonding, DB) it is the ability that the very high outspread rate that uses material to fall in constant temperature and pressure and solid state diffuse, figuration and soldering engineering technology are finished in a hot loop, its technology can use production to reduce the complex component part that weigh and machines without surplus nearly low cost, high. When mould pressing exceeds plasticity alloy sheet, need to have model of a kind of shade or force plug only can, save half mould cost. The function of titanium alloy material suits SPF/DB technology very much, in the production that uses extensively already at the structure such as engine of plane, aviation, missile, spacecraft now. Inferior the alloy such as the TC4 of micron brilliant or Na Mijing, TC11, Ti-10-2-3, TiAl, use technology of SPF ／ DB but will inferior the Ti-6A1-4V alloy plank of micron brilliant shapes an appearance height of complex, organization is even hollow close clean model. SPF/DB technology already received wider and wider application on the production of aerospace component, exceed plasticity figuration structure to be able to make cost saves 20 ％ ～ 40 ％ . The alloy data that uses SPF/DB technology take shape includes steel of titanium, aluminous, magnesian, carbon, stainless steel and high temperature alloy to wait. In recent years, as the wide application of technology of agitate friction welding, agitate friction welding / compound engineering technology got figuration exceeding model develop. Because aluminium alloy is when figuration of applied SPF/DB technology, diffuse to assure connective quality, the technology of film of purify surface oxidation becomes relatively complex, if convert,agitate friction welding is replaced diffuse it is easy that join will make the figuration of aluminium alloy becomes and economy is gotten much. Photograph of Nextpage instantaneous fluid diffuses join diffuses join cent diffuses for solid state join and fluid photograph diffuse join two kinds big. Diffuse the initial stage that join develops basically is to show solid state diffuses join, as diffuse the development of join technology, appeared fluid photograph diffuses join. Instantaneous fluid photograph diffuses (Transient Liquid Phase, TLP) join technology is to go up a kind of when 70 time develop the century new-style join technology. To the research of TLP, apply at aerospace at the beginning advanced material join, the typical case of success application is the join in domain of alloy of Ni radical high temperature. The solderability of alloy of nickel radical high temperature is poorer, use a convention solder the method solders when the alloy of nickel radical high temperature of turbine lamina, of very inaccessible satisfaction solder quality. Alloy of nickel radical high temperature brings about drill rod solder the mechanical function of welding line and corrosion resistance can drop serious, although can realize pair of precipitation aggrandizement and dispersion aggrandizement,solid photograph diffusion welding is received of nickel radical alloy solder effectively, but solder to sample treatment quality demand of the surface is higher, the pressure that diffusion welding receives place to bring to bear on is very great, and solid photograph diffusion welding is received solder hard the component part of alloy of nickel radical high temperature with complex form. To solve afore-mentioned problems, american scientist considered to develop TLP join technology, apply successfully at lamina of turbine of alloy of nickel radical high temperature solder. Instantaneous fluid photograph diffuses join, just as its name implies, when material joins, fluid photograph appeared in interfacial place, diffuse as a result of the atom in fluid photograph rate is rapidder, more be helpful for interfacial atomic diffusing, also can reduce substantially diffuse join place needs pressure, because this weld time shortens greatly, solder pressure also is reduced greatly, can solder thereby the component part with complex form. As a result of two was decided to diffuse by the property of solder material interface whether form fluid photograph, diffuse to achieve fluid appearance effectively so join, often need to add master alloy layer. Intermediate layer alloy is close to for composition commonly at mother capable person, fused temperature under mother capable person or the TLP alloy that can form fluid photograph through diffusing (ply of alloy of the layer intermediate makes an appointment with 30 ～ 50 μ M) . When soldering, after assembling workpiece, below the protection of inert gase, heat to solder temperature, the pressure with bring to bear on constant, intermediate layer fuses above all or can form fluid photograph through diffusing, capable person of embellish wet mother, workpiece cooperates one layer liquid is formed between the face. When heat preservation, the element between intermediate layer and mother capable person diffuses quickly, make interfacial composition produces change, this kind of change brings about join temperature to allot unripe isotherm caky, form solder reliably contact. After isothermal and caky happening, contact organization and mother capable person essentially similar, but there still is a difference on composition, require heat preservation in order to achieve contact class status even. Whole process is: Fluid photograph forms → fluid photograph to diffuse caky → component changes → isotherm equably. When W and Cu join, hot coefficient of expansion and difference of stretch model quantity are big between W, Cu, produce leftover stress and contact craze easily when high temperature joins; And W and dissolve of each other of Cu both neither, also do not form the compound between the metal, have link very hard with diffusion welding directly. Be aimed at this one problem, the task group that the author heads is designed through intermediate layer alloy (like Cu-Mn alloy, Mn-Ni alloy) optimize with TLP craft parameter, the transition that controls alloy to form the specific content with relatively inferior melting point fluid photograph. The phasor of divide evenly brilliant that considering Cu-Mn alloy phasor is the special kind that has dinky place, this kind of phasor is nodded in certain part, line of its fluid look and coincide of solid look line, interval of nonexistent crystallization temperature, become organization of single-phase solid solution in the crystallization below constant temperature namely, unlike great majority transfers fluid photograph is to pass in all brilliant (contain photograph of brittleness of the compound between the metal mostly) and form, the microstructure of the TLP contact that reason wins is helpful for improving the plasticity of contact and crack resistance. Stimulating smooth compound heat source to join laser beam welding is received is one of main fields that technology of laser beam machining uses. 70 time basically use the century at soldering on thin wall material and low speed solder. It is a kind of high quality, high accuracy, low that laser beam welding is received be out of shape, efficient solder with what high speed spends method. Solder as the promotion of laser power social estate and the molybdenum of perfect, metal of fiber-optic transmission technology get together bundle of field lens the development that wait is successful, laser solders to be made in aerospace, machinery, the application of the domain such as industry of microelectronics of medicine of auto industry, pulverous metallurgy, biology is wider and wider. But metallic stuff (aluminous, magnesian, copper) advanced element restricted reflectivity the actual project suitable scope that laser beam welding receives, reach the promotion application in national defence industry to encounter great difficulty in aerospace especially. To widen laser beam welding receives applied territory of the technology, of laser and other method compound solder the focal point that the technology makes each advanced country research, hope have the aid of is other of the method solder the insufficient place that the characteristic will come to to make up for laser beam welding to receive, produce the advantage that laser solders adequately. What laser and GMAW are united in wedlock is compound solder system besides, have the aid of is compound the high energy effect of heat source, hopeful solders the contact form that two kinds of only heat source complete hard, those who obtain only heat source to be achieved impossibly is efficient solder the effect. Have an effect most among them should count laser - electric arc is compound solder technical research and application. Laser - electric arc is compound heat source solders the tall adaptability that the technology has general arc welding already characteristic, have laser to regard as again solder the big frit of heat source is deep, high speed, low be out of shape characteristic, be what in last few years rapid development rises is high grade and efficient solder technology. Aluminium alloy because its reflectivity tall, thermal conductivity is good, demand of social estate of the power when laser beam welding is received is high, easy generation enrages aperture, crackle. Use laser - electric arc is compound heat source solders can solve these problems effectively, the reflectivity of bath of aluminium alloy liquid state under solid state metal, as a result of the action of electric arc, stimulate beam of light can direct radiate arrives surface of liquid state bath, increase absorptivity, raise frit deep. Use dc to be received instead (DCEP) can clear before laser beam welding oxidation film. In addition, the bigger bath that electric arc forms is in stimulate ahead of beam of light to move, increase the wetability between bath and solid state metal, prevent to form bite an edge. Japanese scholar TShida and laser of 10kW CO2 of M Hirokawa application and communication TIG are compound solder A5083 aluminium alloy, appear without air hole and shrinkage cavity in welding line, phenomenon gnawing an edge also is reduced apparently. Laser - TIG compound heat source solders in high speed below the condition, can get stable electric arc, welding line figuration is beautiful, reduced the stomatic, generation that bites the weld defects such as the edge. Especially small electric current, tall solder fast with long electric arc when, laser - of TIG compound heat source solder double what speed can achieve laser beam welding to receive, because of this laser - compound heat source of TIG electric arc basically is used at laminose high speed to solder, also can use at differring of thick material solder. Laser - pulse MIG electric arc is compound heat source solders when aluminium alloy, in identical solder below condition of hot input quantity, the welding line frit that compound solder obtains is deep the pulse MIG solder that is more than identical electric current; In obtain the condition with deep frit of same welding line to fall, the photograph of pulse MIG solder of compound solder and identical electric current is taller than having solder speed, lower hot input is measured and smaller be out of shape. So laser - MIG and laser - TIG photograph is compared, its solder board thick bigger, solder adaptability is taller. Through adjusting the different motive position of electric arc and laser, what can increase pair of space effectively is patient degree, reduce the processing workload of welding line brim. The advantage that its tall adaptability brings depends on, be opposite not only the sensitivity of the clearance, bad side, deviate in be opposite is reduced, still can decrease solder a lot of jobs such as aftertreatment of outfit clip, fixed position, solder. Laser - plasma arc (PA) compound heat source solders have tigidity good, temperature is tall, directional sex of ignition of strong, electric arc good, thermal treatment zone is narrow, right the sensitivity of the outside is small wait for an advantage, special interest solders at having compound heat source. In laminose butt joint, differ thick board zine plate of join, plating is built receive, aluminium alloy solders, cut and exterior alloy changed the application that waits for a respect to achieve favorable result. Use plasma arc to assist laser to be on YAG and CO2 laser undertake thin plate (0.

Armor plate of 16mm thick galvanization) solder, the surface that solved solder of laser high speed effectively to bring shapes discontinuous problem, solder rate rose 100 ％ left and right sides than alone laser beam welding. And, as a result of the interaction between electric arc and laser, make electric arc very stable, although solder,the electric arc when speed is as high as 90m/min also did not appear not steady state, can obtain broader solder line and slick welding line surface. CNC Milling