Laser beam welding of YAG of much beam of light of aluminium alloy thin plate accepts a design

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1 introductive aluminium alloy has weight light, intensity the advantage such as tall, corrosion resistance, apply extensively at the production material such as car, plane, shipping. It is close that the laser beam welding of aluminium alloy receives a technology will 20 years develop the new technology that rise, solder with the tradition technical photograph is compared, it has very large dominant position on soldering efficiency, dependability, precision. The difficulty that aluminium alloy solders is opposite at its the reflectivity of laser is extremely tall, be opposite among them CO: ? Type of some Jia crowded porcelain showing disrespect or contempt chants す badger?0% , adjacent to YAG laser reflectivity 80% . Many document account with high power CO: ? Administer of new bridge of  of す Hun Gu ferociouses add embrace the larva of a tapeworm or the cercaria of a schistosome of hard core kang to circle laser of AG of Liang  miscellaneous Man undertakes aluminium alloy solders research is opposite less. The aluminium alloy sheet metal that enterprise of partial laser beam machining uses YAG laser to be controlled to Lmm solders undertook experimenting study. The engineer of ministry of craft of laser beam machining of limited company of equipment of laser of industry of laser of Wuhan Hunan day passes a test, finish what join of air conditioning aluminium alloy wears smoothly on laser of 50 WYAG solid to solder, intensity achieved user requirement, but solder the surface is rough, have crackle and stomatic presence. Additional, solder to Lmm aluminium alloy through experimenting on 30WYAG laser for many times, although frit is deep bigger, can realize penetrable solder even, but strength of the data after soldering is insufficient, at the same time the surface has apparent flaw, interior has air hole. Partial research organization uses laser - MIG compound solder or the positive result with fill the method of filar solder to undertake aluminium alloy laser soldered to also be obtained certain, but treatment technology is relatively sophisticated. The article received technical craft to undertake study to aluminium alloy laser beam welding, analysed laser of YAG of much beam of light to solve aluminium alloy to solder the possibility of partial blemish, put forward laser beam welding of YAG of much beam of light to receive the smooth region literary composition of machine to establish a method. Laser beam welding of 2 aluminium alloy receives technical difficulty and means of settlement 2.

1 aluminium alloy undertakes to stimulating the fast face of beam of light to reflex laser solders, be being come up against above all also is at the same time very scabrous problem is the intense reflex that the surface shoots laser to the person, the method that can use pair of aluminium alloy surfaces to undertake pretreatment will solve, electroanalysis for example arenaceous or polishing, gush is zincous the method such as oxidation processing. But the complexity that treatment can increase when undertaking exterior craft is handled destroys the surface even, the material that already had made polishing processing in material itself especially criterion this method cannot be taken more. Destroy weldment surface state for both neither, make laser beam welding receives process to simplify at the same time, can use the method that to soldering material has heating beforehand warming up to improve data the absorptivity to laser. Theory and research all make clear, be aimed at infra-red laser, metallic absorptivity and temperature depend on a relation to be able to use below simple expression description: One T0) of A(T)=A0+r(T in type, a0 is the absorptivity that issues a metal in temperature TO, r is the temperature coefficient of absorptivity, t is temperature. Graph the 1 temperature when be laser of metallic stuff illuminate rises notional graph. Graph 1 in A is with CO2 laser, the material temperature when B stimulates smooth illuminate metal to use YAG rises and change condition. Graph the temperature that 1 laser illuminate causes rises and if posture change uses laser of a bundle of YAG to undertake heating beforehand making aluminium alloy temperature elevatory, can raise succeed laser advocate solder the absorptivity of smooth road, what laser beam welding of small-power of thin plate of implementation aluminium alloy receives is likely. 2.

Aperture of coherent of laser beam welding of tall aluminium alloy of sensitivity of aperture of coherent of laser beam welding of 2 aluminium alloy is the common flaw that aluminium alloy solders. Air hole has 2 kinds, what hydric Kong He arises as a result of key aperture cave in is stomatic. The adsorptive moisture in air and the moisture in protecting gas and oxidation film is the main reason that produces welding line stoma. When laser heats, the crystallization water of aluminium alloy surface and water of constitution will be decomposed stage by stage. The moisture in decomposing the moisture that go out and air can be in the high temperature area of laser action decomposes generation hydrogen directly, the hydrogen when high temperature is in bath solubility is very tall, can absorb many hydrogen. If the graph is shown 2 times, because the thermal conductivity of aluminium alloy is very good, in quickness refrigeration process, hydrogenous solubility drops very fast, many hydrogen has not enough time separate out forms air hole thereby. When key aperture mode solders, if key aperture is not stable, melt metal vapour and gas can stay in ministry of welding line root to form air hole thereby. Graph the stomatic sensitivity issue that 2 hydrogen want to solve aluminium alloy laser beam welding to receive in the solubility in aluminium, can use much beam of light to solder the rate with low thermal drop of slow down material and the generation that increase the method of key hole size to reduce 2 kinds of afore-mentioned stoma. Advocate after beam of light has soldered follow beam of light makes the temperature of material reduces rate to decelerate, can pass at the same time adjust with advocate the dimensional distance of beam of light will avoid key aperture cave in and make the metallic steam such as the magnesium in aluminium alloy, zinc stays in welding line to form air hole. 2.

3 aluminium alloy solder hot crack aluminium alloy belongs to a model in all brilliant alloy, when soldering easy generation hot crack. If use laser beam machining of single light beam, material heats and cooling rate is splitting, welding line is dark wide than big, organization of welding line crystallization is directional strong, aluminium alloy solders can mix in welding line metal seam area occurrence crackle nearly. Those who appear in welding line area is crystallization crackle, appear in what seam an area nearly to be liquefacient crackle. Solder in laser commonly when, seam an area nearly very narrow, it is about under 2O0 η M, won't right whole solder contact causes very great harm, so important is to be like crackle of crystallization of far more than. Generally speaking alloy part is larger possibility that produces crystallization crackle is larger, solder number of the crackle in rate is older welding line is more. Occurrence above circumstance is cooling rate too fast and alloying element cannot originally completely dissolve in crystallization and heat change of the bulk when refrigeration is very big, generation is very large be out of shape at stress and action at happening crystallization crackle arises on the crystal boundary of brilliant in all. The test that in Chu Tianji ministry of craft of laser beam machining of limited company of equipment of smooth industry laser has discovers, when should be laser of YAG of 30 W single light beam to undertake aluminium alloy solders with average power, if use high speed for many times,scan and every time leave anxious quantity different to undertake soldering experimenting, discover welding line crackle decreases apparently finally, solder intensity increases. If use much beam of light to solder, can pass adjust advocate beam of light and follow the distance of welding line of edge of beam of light lowers its cooling rate thereby, achieve decrease solder the effect of hot crack. Laser beam welding of YAG of much beam of light receives sheet metal of 3 aluminium alloy 3.

Of laser of YAG of 1 much beam of light solder beam of light is decorated use laser of 3 beam of light to undertake aluminium alloy solders, ask according to soldering specificly, can use the beam of light such as serial type, paratactic type, across type to decorate means, if pursue,3 are shown. Graph light beam of laser of 3 much beam of light arranges a plan 3.

Laser of YAG of 2 much beam of light is basic smooth way of system of smooth road design is mixed by hard smooth way two fiber-optic those who transmit is flexible smooth road in all 3 smooth roads are formed. If the graph is shown 4 times, after the laser light beam of average power 50 W is shot from inside syntonic antrum, spectroscope will go out shoot laser to divide successful rate to be 2 ∶ 2 bundles of laser of 1. The 330W left and right sides that occupies general power 2/3 among them stimulates beam of light to pass enlarge bundle focusing outputs key light bundle. The laser that occupies general power 1/3 bundle again by turn over spectroscopic cent to be 2 bundles of laser with equal power partly fully partly, can achieve respectively lotus root closes fiber-optic in undertake focusing is outputted transmission, power can achieve 70 W left and right sides about. Graph 4 in 7 OK and electronic-controlled made freedom inserts person smooth journey, make output smooth road to turn into by single light beam two beam of light or 3 beam of light. Generally speaking, aluminium alloy laser solders to be 105- 106W/cm2 in power density between when, density of power of; of solder of implementation thermal conductivity is in 106-107W/cm, between when, realize deep fusion welding. It is 50w to average power, YAG solid laser, power of its pulse peak value can amount to 10kw, after laser facula passes collimation focusing, the diameter of focusing facula can be amounted to 0.

Lmm, laser power density can amount to 108w/cm2 left and right sides near the focus, can realize laser deep fusion welding completely. Systematic design makes key light road outputs power to occupy the 2/3 of general power, the critical power that exceeded deep fusion welding of aluminium alloy laser 4.

0*l06w/cm2, can realize laser deep fusion welding. Graph literary composition of smooth region of 4 much beam of light proposes a plan 1, turn over diaphragm partly; 2, 1/3 turns over diaphragm; 3, energy probe; 4, fiber-optic observation lens; 5, turn over diaphragm partly fully partly; 6, total reflection diaphragm; 7, shunt smooth brake; 8, device of fiber-optic output coupling; 9, fiber-optic outlet; 10, laser beam welding of YAG of 4 epilogue much beam of light receives unit of fiber-optic input coincidence aluminium alloy is the cent of beam of light of same laser 3 bundles, beam of light distributings agile, synchronism solders, hopeful the partial blemish that solves laser beam welding of aluminium alloy thin plate to receive a process. If gas of reasonable use protection sets appropriate craft parameter, the YAG laser beam welding that solves aluminium alloy thin plate likely accepts a hard nut to crack, solder to use the YAG solid laser of high-power thick board provide reference. CNC Milling CNC Machining