Technology of finishing of magnesium alloy laser is analysed

Foreword magnesium alloy has density small, than intensity, taller than stiffness, thermal conductivity is good, good electromagnetism screen character and damp damping ability. Magnesium alloy has been replaced a lot of zinc, aluminous, cast-iron wait for material with steel, apply extensively at the industry such as aerospace, car, computer, communication, especially automobile industry is added urgently to the demand of magnesium alloy spare parts, make the application of magnesium alloy shows driving development tendency. However, the wearability with poorer magnesium alloy, be able to bear or endure the play that corrode sex is restricting magnesium alloy latent capacity. Accordingly, the finishing technology of magnesium alloy is taken seriously by the height of investigator. Laser finishing technology is a when nearly ten years development rises new technology, handle a technology at modified of current surface of magnesium alloy material relatively, because laser method can undertake local and fast heat and react through choosing wavelengh to make its produce specific chemistry, to material surface so modified can have tremendous effect more. Laser finishing method basically has laser face posture to change reach frit of surface of concussion sclerosis, laser to coagulate, laser surface alloy is changed reach Fu of laser surface frit to wait. Among them, using the technology of laser surface modified in magnesium alloy basically is laser frit coagulates, laser alloy is changed reach laser frit Fu. 1.

Frit of surface of magnesium alloy laser coagulates laser frit coagulates is to use the laser of high power density to be inside cutty time with metallic interact, what metallic surface local district instantaneous heats to make to quite high temperature is fused, subsequently have the aid of is mixed at the metallic matrix absorption of heat of cold conditions conduct heat the metallic surface layer that the process makes fuse is fast and caky, change organization of spare parts surface layer and property thereby. Because heating quickly and this one process is completed below fast refrigeration, the sclerotic layer organization that gets so is fine, hardness also the hardness that prep above convention quenchs. The exterior hardness that this kind of technology raised metallic stuff and part, wearability, be able to bear or endure corrode sex and intensity and high temperature capability. Below vacuum condition, magnesium alloy undertook pair of Az91hp such as Gao Yali laser frit coagulates processing. The result discovers frit of magnesium alloy laser coagulates the layer basically is by α 3/mg photograph and β - Mg17al12 photograph place is formed. As the addition of laser scanning speed, frit coagulates a hardness, wearability also increases subsequently. But fall in different scanning speed, laser frit coagulates the layer is able to bear or endure corrode sex relatively matrix magnesium alloy is reduced somewhat, and as scanning speed reduce, frit coagulates the layer is able to bear or endure corrode sex drops extent increases. A Kousomichalis, Ceng Aiping Az3lb4h sample outside that leaves illuminate burnish to pass in vacuum condition with Krf laser. Discover sample surface is microscopical form appearance is moire shape, and the surface after laser processing and the sample appearance that did not handle are compared show tensile stress. Laser handles a 30 μ M microscopical what hardness compares matrix is low, laser is treated sample is able to bear or endure corrode sex has bigger rise. Use Nd:yAg laser, two kinds of magnesium alloy undertook pair of Az91d such as D Dube and Am06b laser frit coagulates processing, its micromechanism is shown dendritic, grain gets refining, of the Am60b magnesium alloy of although classics is ultra smooth heat treatment corrode Az91d of function prep above, but did not obtain rise significantly. Can reduce corrosion resistance significantly below certain technology parameter even can. Yaojun undertake in surface of Az91d magnesium alloy laser frit coagulates, frit coagulates a formation microcosmic organization structure is evener, corresponding land increased laser frit to coagulate the wearability of the layer. Use the CO2 laser of 2kw successive wave, g.

Pair of A3z1 such as Abas, Az61 and surface of We43 magnesium alloy undertake laser frit coagulates, frit coagulates sample is worth to be in Ph by immersion below 20 ℃ 10.

The sodium chloride of 5 (quality mark is the 10d in 5%) solution, show the magnesium alloy after coagulating through laser frit as a result be able to bear or endure corrode sex got rising, refined the micromechanism of alloy, increased alloying element to be in. The chroma in photograph solid solution, make β photograph distributings more equably, formed 1 to be able to bear or endure corrode layer. Nextpage2.

Alloy of surface of magnesium alloy laser changes laser surface alloy is to pass fused matrix surface to besmear beforehand the velar layer of Fu and partial matrix, perhaps note a person while the surface is fused certain powder, velar layer or surface happen after the liquid state in bath mixes fast and caky, form an alloy layer that has expectation property in the surface thereby, in order to improve matrix performance. Some closer year come, aluminium and alloy of surface of aluminium alloy laser change research more active, and the research that changes to the laser surface alloy of magnesium and magnesium alloy not a lot of. Wang A A undertake with laser on magnesian matrix Mg and Al alloy change processing, through the electorate electron diffraction of Tem stain discovered the existence of magnalium alloy, the corrosion resistance of its sample can excel casting magnesium and magnesium alloy. R Galun introduce the element such as aluminous, copper, nickel and silicon, use 5kwCO2 laser undertakes to magnesium alloy surface alloy is changed.

Fused deepness is 700-1200 μ M, exterior hardness achieves 250hv. The quality mark of alloying element is exterior alloy layer 15%-55% , when the copper alloy that add a person, corrosion resistance can have bigger improvement, and the corrosion resistance when the aluminium alloy that add a person can increase significantly. 3.

Technology of Fu of frit of laser of Fu of frit of surface of magnesium alloy laser is to use high-energy density to stimulate beam of light to will have the alloy of different composition, function and matrix surface to fuse quickly, the fast and caky process of the alloy layer that has completely different composition and property with matrix is fashioned in matrix surface. Layer of generated surface layer alloy matrix and corrode medium to isolate, of material corrode function to be decided by alloy layer. Because finishing of magnesium alloy laser does not need the harsh ambient conditions such as vacuum, lesser to work measure limitation, in recent years, as technology of laser frit Fu ceaseless and perfect, the application that its refuse corrode sex respect in magnesium alloy surface more and more get the attention of domestic and international investigator. In the reative cell that Wang Anan fills inert gase in similar vacuum, use 10kwCO2 laser undertakes layer of alloy of magnalium of laser frit Fu to pure magnesium. Generated on the interface in all brilliant layer, the composition of modified alloy layer is α - Al and β - Mg2al3 corrosion potential was moving about 0.

7v, the corrosion resistance that shows laser handles magnesium alloy can excel pure magnesium. Yue T M undertook the Nd:y of Mg-sic composite material below groovy environmentAl-si of Fu of frit of Ag laser surface in all brilliant alloy, and stainless steel of Fu of frit of laser of two footwork craft is used on Mg-zk60/sic composite material. The Al-si alloy layer of Fu of former place frit, corrode electromotive force not to have apparent change, but, corrosion current density reduced 2 amounts level than base material. The metallurgy union layer of latter sample is admirable, corrosion potential is 820-1090mv, the average data with average outclass and corrosion current of spray material; 1 reduced level of 4 one 2 amounts, both raised magnesian fund accordingly to belong to composite material ground to be able to bear or endure corrode sex. Additional, yue T M still is excogitated apply the means that blow pink to be not brilliant alloy Zr65al7 in Fu of frit of the laser on magnesium radical metal.

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5, frit Fu ply is about 1.

5mm, matrix surface Fu has an organization that be not brilliant, appear without crystallization organization. Matrix of frit Fu sample and surface have admirable metallurgy couple, without poriferous exist with crackle, wearability and be able to bear or endure corrode sex all excel not the sample of frit Fu. 4.

Look into frit of surface of magnesium alloy laser to coagulate the method is simple, mix to hardness be able to bear or endure corrode sex all has rise, but the rate that raise is finite. Laser surface alloy changes the alloy layer that can design different hardness, although the interface is metallurgy union, but form even alloy to change a layer hard. Laser frit Fu can introduce tall hardness, Gao Naishi sex and the element that Gao Rong nods in magnesium alloy surface, can form the aggrandizement layer with exterior superior performance, show metallurgy couple with matrix, it is the effective method that improves performance of magnesium alloy surface. Ban gold stimulates the development of gold vessel of Ban of Ban golden light, robot and automata technology as Ban gold, technology of laser surface modified will side with high-power automation, the way that intelligence changes strides. Laser finishing technology does not have negative effect almost to environmental protection, regard a kind of high speed as efficient exterior modified technology, already obtained many positive result in a lot of respects, improving performance of magnesium alloy surface, the effect that lengthens play of respect of its service life is more and more apparent, taking economic benefits is more and more remarkable also, future can have huge to apply foreground in anticorrosion engineering field. CNC Milling