Laser technology repairs medium application in plane structure injury

Time:2023-06-26 11:48:22
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source:PURELIFE CNC Machining

20 centuries since the 1st laser invents 60 time, laser has the good quality such as sex of tall directional, tall brightness, tall monochromatic and tall coherence because of its and be applied extensively at a lot of domain, become ideal treatment heat source. The power density on spot of gloriole of laser classics focusing can amount to 104~1015W/cm2, metallic stuff issues meeting instant to warm up quickly in the illuminate of tall power density light, fused even instantaneous vaporization. Accordingly, the power density with different application and heat effect time, laser can realize remelting of exterior heat treatment, surface, alloy to change, frit Fu, solder, the different treatment goal such as aggrandizement of concussion of cut, stiletto, surface, dispute often adds heat source ideally. The exterior modified technology of laser beam machining already made a domain get applied in engine of plane structure, aviation. Our country uses guider of ministry of coronal of lamina of turbine of engine of aviation of founding of technology of laser frit Fu, turbine, recovered loss successfully appearance, dimension and function. Some closer year come, as the fast equipment of new machine, titanium alloy and composite material already became my army the main construction material of active service plane. And because laser has the good quality such as tall directional, tall brightness, tall coherence and be applied extensively at each domains, it also is sure to repair a domain to act important role in plane structure. When technology of laser beam machining applies technology of 1 laser heat treatment to wash face of metal of illuminate of beam of light with what fixed rate moves, surface layer metal absorbs energy hind to warm up quickly, after facula is mobile, base material absorbs the quantity of heat of surface layer to make the temperature of surface layer metal drops quickly with extremely high rate, form what quench unlike convention to quench oneself. Drop in temperature as a result of what quench oneself rate is extremely high, because of this exterior modified layer with attainable special microstructure, this has favorable effect to increasing metallic hardness, wearability, corrosion resistance, fatigue resistance. Laser heat treatment is the technology of laser beam machining that develops the earliest, already formed more perfect theory and project application technology now. To can changing the carbolic steel of aggrandizement, alloy structure steel, it is OK that laser surface quenchs generation tradition quenchs taller hardness, also have certain aggrandizement effect to having the stuff of a few mild steel of rigid of temper by dipping in water even. Graph the 1 laser that is 35CrMo steel quenchs the effect. Application of technology of remelting of 2 laser surface quenchs than laser surface face of faster metal of illuminate of laser power density can make surface layer metal fused, after facula is mobile, base metal absorption of heat makes liquid of the metal inside bath rapid solidify, form stimulate strongly have extremely fine grain and microstructure of supersaturation solid solution coldly, as a result of the action of fine brilliant aggrandizement and solid dissolve aggrandizement, can raise the hardness of material surface, wearability apparently. Consider to make clear, pass remelting, the hardness of aluminium alloy can raise 30%~100% , this is the technology of laser beam machining with the simplest craft, but the range of aggrandizement is narrow. Hand in to bearing change the profile of plane structure aluminium alloy of load, plank, the fatigue character of the overheat layer that exists necessarily after laser remelting is the key that decides structural service life, accordingly, need before entering project application be opposite with remelting of laser of experiment test and verify the influence of material exhaustion function. To structural steel material, remelting sclerosis effect is distinct, the graph is shown 2 times for remelting of 45# steel laser different area is organized. By the graph 2 can see, the organization after laser remelting is changed into martensite by pearlite. Alloy of 3 laser surface changes a technology to fuse the alloying element of the design is added to bath when surface layer metal in laser, the alloy that gets needing property in surface layer below the premise that can not changing matrix alloy class status changes a layer. This technology is made to what special function needs a part very advantageous, the blame that can make a traditional production technique cannot come true all material the qualitative, metal that is not even function or composite material spare parts. The bath in changing a course as a result of laser surface alloy drops in temperature rate is extremely high, can form structure of the alloy that comes true hard below condition of traditional metallurgy technology, organization. Accordingly, the basis needs to be able to form tall hardness, wearability, good corrosion resistance can change a layer with the alloy of heat-resisting function. Be aimed at aluminium alloy, people experimented the laser surface alloy of all sorts of different alloy systems changes technology, wait like Cu, Fe, Si, Ni, Cr and WC, SiC. Among them nickel radical alloy changes a dispersion to have look of AlNi of the compound between the metal, Ni3Al, have taller hardness and wearability, but alloy changes a layer more fragile, put in craze phenomenon. The combinative interface of laser frit Fu is put in the alloy of matrix and frit Fu material to change metallurgy course necessarily. Graph 3 change composition scanning curve for aluminium alloy alloy. Nextpage4 laser beam welding receives density of technical laser energy tall, can make surface layer metal fused in the instant, aerification, it is soldering ideal the sources of energy, can obtain width the good welding line with small area of narrow, hot influence. Had acquired the welding line of high quality below a variety of a variety of metals, conditions at present, it is the technology of laser beam machining with wider application. The high strenth such as commonly used to plane structure LY12(2024) , LC4(7075) , weldability can be poorer be out of shape aluminium alloy, laser beam welding is received is to most those who develop a future solder technology. Application of domestic and international researcher is continuous CO2 laser, Nd:YAG laser, semiconductor laser, accurate element laser is the sources of energy, came true with different craft parameter idealer 2024, 7075, 6063, 5083, 5052 wait for alloy plank to solder, undertook finite yuan of analysis. Accordingly, laser beam welding receives a technology to repair a domain to have quite wide development perspective in plane structure, injure domain of rush to repair in plane structure especially, because its are had,solder speed fast, construction relatively the characteristic with simple riveting, it is the good technique that replaces riveting craft. To material of titanium alloy, high temperature alloy, stainless steel, laser is ideal solder the sources of energy, can form heat to affect an area welding stress is small, little, be out of shape the welding line with small, high performance. Laser of technology of 5 Laser Cutting is OK cut is almost all material, and can pass method of cut of choice aerification, fused, oxidation and craft parameter and cut in what high quality gets in different material cut seam the surface. Laser Cutting is out of shape small, precision is tall, economic efficiency of material, cut is tall, right environmental pollution is little. Domain of rush to repair is injured in plane structure, technology of applied Laser Cutting can excise structure of injury, metabolic quickly, create economic and execution condition, valuable time to carry out repair. Technology of aggrandizement of concussion of laser of technology of aggrandizement of 6 laser concussion is the surface of another kind of material after afterwards gush bolus, cold extruding aggrandizement technology, arrive at material surface when the laser of density of extremely high power, short pulse, the material of low melting point will be rapid aerification, the is equivalent to explosion instant aerification of surface layer material produces bow wave to be able to produce intense mechanical effect to matrix. Accordingly, the material appearance that handles in need beforehand metal of buy low melting point or metalloid coating, after classics laser illuminate, can raise material surface hardness substantially (raise 5 times above) , the surface presses stress, to rising the fatigue resistance of base material can have distinct effect. Consider to make clear, the main mechanism of laser concussion aggrandizement is grain of surface of the metal when aerification bow wave wrong density is even, rise substantially, complex complete a business transaction, intricate interact forms even exterior remains to press stress, reduce fatigue crackle thereby patulous rate, the range that improves life amounts to 20%~300% above. Can see, perspective of this technology application is wide, wait for conventional technology in the alveolus with aviation common structure, welding line, groove especially cannot the special place of aggrandizement (like rivet aperture) , laser concussion aggrandizement is the new technology that other technology cannot replace. Fu of frit of surface of laser of technology of Fu of frit of 7 laser surface is in metallic matrix apparently beforehand metal of Tu Yi layer, alloy or powder of pottery and porcelain, when laser remelting, control energy inputs parameter, make add a layer to make after melting adequately matrix small frit and matrix implementation metallurgy are united in wedlock, get an adscititious frit cladding that has need property thereby, the graph is shown 4 times analyse for SEM of laser frit cladding. Change photograph comparing with laser surface alloy, what matrix avoids in this process is excessive and fused, maintained the character of the material inside frit cladding and function, it is very main exterior modified technique, application can achieve enormous technical beneficial result to plane structure. This method was applied at was being caused after lamina of turbine of air bus engine to take seriously extensively by successful ground 1981, already made one of research focal points of modified of surface of domestic and international laser. Hardness of aluminium alloy material is low, in Fu of its surface frit a good wear-resisting layer sense is particularly great. But difficult is, the coefficient of thermal conductivity of aluminium alloy tall, melting point is low. And the melting point of frit cladding normally greatly matrix of prep above aluminium alloy, the alloy that forms dilute to spend small, function to stabilize hard changes a layer. Carry out a proof, the course controls laser technology parameter strictly, can realize need function and characteristic alloy surface layer, tests of a variety of alloy frit Fu had successfully domestic and internationally in aluminium alloy surface. Abundant field company already enraged engine valve base by original mosaic structure instead direct frit Fu, make the wearability of valve base, lubricity, thermal conductivity rise considerably. Abroad not only use laser frit Fu at exterior modified, also use at the rehabilitate of mechanical spare parts, develop from this studied laser shapes quickly technology (DMD, DMP) , make what be used at mechanical spare parts directly. Wear away to the surface of mechanical spare parts and corrode injury, can use laser multilayer the method of frit Fu restores its dimension and appearance. The corroded injury to undertake succeeding rehabilitate of the aluminium alloy structural member that American navy already built special laser frit Fu to repair a lab to equip to underwater. To navy the plane corrodes injury commonly, technology of laser frit Fu has tremendous development application perspective. Technology of laser beam machining of foreground of development of technology of laser beam machining got used to modern plane greatly be opposite in rush to repair alloy of titanium alloy cut, titanium solders, the extensive need of the cut of composite material. The power density that should adjust laser only and facula shift speed can achieve a variety of treatment goals, conventional treatment craft can not is likened to. It can make the first selection that remedies flaw of technology of traditional rush to repair technology of advanced rush to repair, also be the technology of rush to repair that has development perspective greatly. The exterior modified technology of laser beam machining already made a domain get applied in aviation engine. Ministry of coronal of lamina of turbine of engine of aviation of founding of technology of Fu of use laser frit, restored blade axial measure successfully. The domain is repaired in plane structure, technology of laser beam machining has begun to get attention, canada labels his the technology that has great value. But the main material aluminium alloy to plane structure, because boiling point is low, conduct heat fast, low to the absorptivity of laser, laser beam machining is more difficult, it is the difficult problem with accepted domain of application of domestic and international laser. If can successful applying, have very high learning value and project application value. On the research of technology of laser rush to repair, our country navy already went in domestic forward position. Waited for development of place of scientific research courtyard by institute of naval aviation project 2006 " system of rush to repair of movable type laser " had begun to deserve to send troop, repair at plane structure for laser technology application and even war rush to repair created a condition. CNC Milling