Be not the research of technology of groovy laser beam machining

1 water guides laser principle and its characteristic water guide laser (Water-jet Guided Laser) is the fiber-optic system that is medium with imperceptible current, with current guiding high-energy laser has the new technology of treatment to workpiece. Because water and airy refractive index are different, distributinging clarity of steady stream and air interface, current stimulates beam of light mediumly to be in of water inside exterior happening total reflection, make laser energy is restricted in water bundle in, the energy that distributings equably through sectional energy is being formed after total reflection for many times bundle (if pursue,show 1 times) . Graph 1 water guides astigmatism comes loose fine treatment principle pursues the characteristic of this technology has: (1) cools as a result of water efflux, hot influence area is small, hot leftover stress small, micro-crack is little; (Because 2) erodes action reduces melt to coagulate again apparently content; (3) is not sensitive to the change from anxious quantity, but complex surface material mixes cut multilayer material, cut seam taper very small; (The laser energy of 4) treatment area distributings even; (5) can machine blind chamfer (aperture) with three-dimensional structure. This technology suits to have the treatment of imperceptible structure very much, be like silicon chip delimit cut, the treatment of the small structure in the treatment of small structure in medical apparatus and instruments and electronic product and MEMS and small part. 1.

2 crucial technologies 1.

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1 laser and water bundle coupling technology (1) laser and water bundle coupling transmission laser inputs water bundle have two kinds of contrail: One kind is called child midday light (also say to draw near axial light) , show incident light carries water bundle axes; Another kind does not carry water bundle axes, call oblique fire the light (if pursue,2 are shown) . Child the contrail of midday light is in those who include fiber-optic light axle from beginning to end advocate sectional inside, in water bundle the interface happens ceaselessly contend for reflection, form music refraction way, the condition that produces total reflection is an angle of incidence must be more than critical an angle of incidence. Oblique fire light and water bundle the center is not inside a plane, with water bundle central axle is different face linear, consequently, oblique fire light is in water bundle in the course reflexes gloriole rail mark for many times is with water bundle central axes is equidistant dimensional helix broken line. In contrail of oblique fire light, the light with right choice and water bundle deflection quantity of the center, can make laser energy is in water bundle distributing mediumly even. Graph 2 lights what go up in face of water Shu Duan is umbriferous (2) laser is in water bundle in in transmitting a process through water layer, transmitted energy loss laser has energy loss, power of laser peak value jumps over Gao Jineng to estimate a loss bigger also (if pursue,3 are shown) . Graph 3 water absorb fine of Shu Guang of water of Nextpage (3) of relation of curve and density of transmission rate and energy of laser pulse peak value to generate a technology to want to generate relatively ideal water to different wavelengh laser Shu Guang fine, form water bundle quality is very crucial. Influence water bundle the main factor of quality has coupler to enter water and condition giving water, the pressure of spray orifice quality and geometrical appearance and water. Of the water in coupler flow if field is in asymmetry to distributing, affect water not only bundle quality, in the meantime, the meeting when stimulating beam of light to pass water layer produces tiny deflection, affect the alignment of laser and spray orifice. Enter the research of water means to discover as a result to coupler with emulated method, the fluctuation surface parallelism of antrum of the coupling device that uses 8 entrances, water appears deviation (show 4 times like the graph) , the stability impact of convection field is very little also, reduced the production difficulty of coupling device. The geometrical appearance of spray orifice is right water bundle the influence of quality is shown 5 times like the graph. Form return the water when flowing bundle quality is best, the surface on requirement spray orifice has lesser exterior surface roughness, radius of pointed horn of spray orifice entrance (R) wants very small. Graph field of 4 coupler current emulates a graph the pressure of water of model of efflux of nozzle of 5 plain top is right water bundle form have very big effect, graph 6 gave out to be below the condition with spray orifice certain diameter, different and hydraulic with water bundle the relation curve of stable length. Graph 6 hydraulic to stabilizing water bundle length is affected 1.

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Light of 2 water derivative machines systematic place to build a system to be mixed by water supply of system of laser, workbench, coupling, high pressure place of treatment process testing system is comprised (if pursue,7 are shown) . Laser is the JK702HYAG laser of British Lumonics company. Workbench is workbench of three-dimensional numerical control. The coupling unit that includes to be able to realize 3 axes fine tuning in coupling system and optics aim a system, can come true stimulate beam of light and spray orifice accurate alignment. Graph 7 water guide Nextpage 1 of system of laser beam machining.

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3 treatment effect guides as a result of water laser beam machining has afore-mentioned advantages, its machine the effect laser beam machining of remarkable excel convention. (1) heat affects an area to reduce the cooling effect as a result of water apparently, water guides the heat of area of laser beam machining affects degenerative layer very small (if pursue,8(a) place shows) . (2) frit bits is cleared the effect because of high speed current erode, water guides the purify effect of bits of frit of laser beam machining is very distinct, the blind aperture that can machine high quality even or blind chamfer (the 8(b) that be like a graph and (C) place is shown) . (Because current of laser classics high speed is conducted,3) does not accept the restriction of focal length position, in water bundle inside stable range, its diameter change is very little, so workpiece is in stable water bundle change of anxious to leaving quantity is not sensitive inside limits, can machine rise and fall metabolic workpiece (place of the 8(d) that be like a graph is shown) , treatment taper (rake) be less than groovy laser beam machining significantly. Graph 8 do not become rusty the groovy laser of firm 1Cr18Ni9Ti and water guide Laser Cutting effect 2 be based on body to heat the technology of Laser Cutting glass of the law 2.

1 principle and characteristic glass have two kinds of typical forms to the absorption of laser: One kind is the surface draws a shape, another kind is body draws a shape (if pursue,9 are shown) . From the absorption of boracic silicate glass, soda-lime glass and quartz spectrum can see, it is when laser wavelengh when above of 5 μ M, glass has very tall absorptivity to its, so wavelengh is 10.

The CO2 laser of 6 μ M enters the deepness of vitreous surface to be not worth a few micron to be absorbed in vitreous surface. When using CO2Laser Cutting glass, crackle begins to expand from the surface, cut quality is poor, the ply of cut glass is very finite, and cannot cut is multilayer glass. And wavelengh is 1.

The YAG laser of 064 μ M can pass through glass, glass is right of laser energy absorbing is body draws a shape, vitreous craze is to be connected equably those who appear. Graph 9 glass are based on body to heat to drawing a shape two kinds of laser the technology of Laser Cutting glass of the law is a transient state essentially heat is conducted, the process that causes thermal stress and crackle to expand. Glass draws laser energy, along laser scanning contrail is in vitreous whole temperature to lift quickly, quantity of heat passes circumjacent area with heating up conductive form again, edge laser forms a heat to affect an area near scanning contrail, and temperature of place of laser dot illuminate is highest. Quick temperature is elevatory cause glass to expand, generation presses stress, and vitreous fluctuation surface drops as a result of air convection temperature again and generation pulls stress, should pull stress value to achieve rupture when intensity, crackle is patulous. Through controlling laser scanning contrail controls crackle patulous method, realize vitreous Laser Cutting thereby. Method of this kind of YAGLaser Cutting glass that is based on body to draw a shape can get better vitreous cut quality not only, and the ply of cut glass can increase greatly, but cut is multilayer glass, sandwich glass and vitreous canal, the cut to glass can come true to finish, need not fabricating, in the meantime, besides it is OK to undertake sharp cut is returned the curve of lay off random. Nextpage 2.

2 crucial technologies 2.

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Emulation laser of 1 temperature field and stress field heats positional temperature and stress state are body heats the main factor of laser glass cut, accordingly, article is useful and finite yuan of numeric analysis method to its temperature and stress change circumstance undertake emulation an analysis, graph 10 ～ pursue 12 it is analytic result. From the graph 10(a) can see, direction of temperature edge ply (Z to) it is to distributing even and size is equal, the local temperature that stimulates spot illuminate is highest. Can seeing way of ply of edge of stress σ Xz from graph 10(b) is inhomogenous equal, whole ply direction is laser dot ahead inside a paragraph of distance draw stress position, and laser nods rear fluctuation surface to appear pull stress. And among appear press stress. Graph 10 T=3.

Distributinging graph of the temperature field of cut of glass of contrail of laser of the edge when 0s and stress field 11 for contrail of scanning of laser of different time edge method of surface of vitreous board fluctuation and the stress of the method intermediate distributing curve. Graph 12 go up with the method intermediate for method of vitreous fluctuation surface the stress change course of the initial drop, dot central and terminus. Graph contrail of 11 edge laser scanning method of surface of vitreous board fluctuation (Z=0.

25mm) and intermediate method (Z=1.

The stress of 25mm) distributings graph initial drop, central dot and 12 end paragraph the σ Xz stress of the dot changes course 2.

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2 tests system pursues 13 for test facilities sketch map, basically mix by workbench of numerical control of YAG successive laser, 3 coordinate infra-red hot composition resembling appearance. Graph photograph of 13 test facilities 2.

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Diamond of contrast of 1 cut effect or hard metal annulus glass cutter is underlined in vitreous surface, break off with mechanical method next the metallograph of vitreous cut optics that glass gets is like graph 14(a) place to show. Graph 14(b) is the metallograph of optics of vitreous cut surface that cut of diamond emery wheel gets. Graph 14(c) is the metallograph of optics of vitreous cut surface that YAGLaser Cutting gets, can see from inside the graph, the cut that uses YAGLaser Cutting soda-lime glass to get is flat, without drossy, without show micro-crack, quality is apparently good the cut quality that gets at rigid standard and cut of diamond emery wheel. Graph 14 3 is planted the Nextpage 2 of cut optics metallograph that vitreous cut technology gets.

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2 multilayer laser of YAGLaser Cutting CO2 can the glass with smaller cut, more cannot cut is multilayer glass, restricted its to apply greatly. And glass has 20% to control only to the absorptivity of YAG laser, when whole ply direction laser energy has absorb, draw a shape for body to the absorption of YAG laser, crackle is connected in whole ply direction appear craze, because of this YAG laser but the glass that cut ply amounts to 20mm above, still but cut is multilayer glass, improved cut efficiency greatly. Graph 15 for sketch map of 4 glass cut, graph the 16 cut metallograph that are 4 glass, among them, (A) ～ (D) is the 1st ～ respectively photograph of cut of face of 4 glass fluctuation. The sketch map of 4 shoes Li reachs graph 15 YAGLaser Cutting the cut photograph of cut of glass of layer of 16 4 of experiment plan plan 2.

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Glass of 3 curves contrail and the dominant position that the YAG laser YAGLaser Cutting that glass is in charge of stresses another times of glass can have the cut of aleatoric curve contrail namely. Normally, basically be to curvilinear cut of glass through mould march the line is underlined, reoccupy machinery law is broken, wait for fabricating through abrade polish next, get the glass with cut better quality. And have curvilinear cut with laser, just can finish cut, need not undertake an aftertreatment. In the meantime, through numerical control process designing can implement the tall qualitative, efficient cut of complex curve. Use this technology to be able to implement the cut that glass provides, graph 17 it is the test specimen that is in charge of with YAGLaser Cutting soda-lime glass and glass. 3 conclusion are opposite soda-lime glass of cut of contrail of curve of edge of laser of graph 17 YAG and the picture that Li Li provides technology of laser beam machining had two kinds of unusual plan relatively systematic research, if make conclusions,reach: (1) water guides clear light machines the advantage that has place of groovy laser beam machining to be not had, have very high treatment quality, and can machine blind aperture or blind chamfer. (2) body heats the technology of Laser Cutting glass can implement cut of glass of efficient, high quality, can implement complex form cut of glass not only, can undertake at the same time multilayer glass and the cut that glass provides, provided effective technology measure for vitreous cut. CNC Milling CNC Machining