激光焊接原理及实践应用讲课资料.ppt

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1、激光焊接LasersWeldingGirishP.Kelkar,Ph.D.激光LASER受激辐射式光频放大器的英文第一个字母的缩写LightAmplificationbyStimulationofEmittedRadiation请记住…..Remember…..学习需要积极的参与Learningrequiresactiveparticipation不耻下问Feelfreetoaskquestions无所顾及地提出个人不同见解Donothesitatetopresentdifferentviewpoints光Light光是一种电磁辐射Lightiselectro-magneti

2、cradiation我们听不到.Wavesthatyoucannothear可见光的波长在0.4-0.7微米之间。Visiblefrom0.4-0.7micronwavelength波长小于0.4微米是紫外线和X光Below0.4–ultraviolettox-rays波长大于700nm的光为红外线和微波。Above0.7–infra-redtomicrowaves0.40.7µmµmVisibleGammax-rayUVIRMicrowaveTVRadio0.01µm0.001µmYAG1µm光的吸收和颜色AbsorptionandColor物体的颜色来源于它反射的光的波长

3、Colorofanobject(wavelengththatitreflects)颜色和光的波长是相关联的。Colorisassociatedwithparticularwavelength黑色和白色代表着什么？Whatisthemeaningofblackorwhitecolor?黑色表面吸收了YAG光，而白色在反射了大部分光。BlacksurfacewillabsorbYAGlightwhilewhitewillreflectmostofit我们为什么需要激光？WhydoweneedLasers?材料加工需要吸收很强的光。Absorptionformaterialspro

4、cessingrequiresveryintenselight高强度的光可以通过激光聚焦成光束获得。Intensitycanbegeneratedbyfocusingabeamoflaserlight普通光不能聚焦成很高的能量密度（或足够小的点）Ordinarylightdoesnotfocusdowntoahighenoughpowerdensity(orsmallenoughspotsize)手持放大镜可以把太阳光聚焦让纸燃烧但是不能把金属融化Hand-heldlenscanfocussunlighttosetfiretopaperbutnotenoughtomeltme

5、talLightandLasers单频的（单波长）Monochromatic(singlewavelength)校准的（平行光）Collimated(parallel)激光LaserLight普通光OrdinaryLight很多波长Manywavelengths不平行NotparallelLightandLasers激光LaserLight普通光OrdinaryLight激光的聚焦FocusingofLasers激光LaserLight普通光OrdinaryLight单频（单波长）和校准（平行）的光可以聚焦成很小的焦点Monochromatic(singlewavelengt

6、h)andCollimated(parallel)lightcanbefocusedtoaverysmallspot激光的种类TypesofLasers激光能量传输LaserPowerDelivery连续波ContinuousWave(CW)脉冲PulsedQ-开关Q-switched激光频率LaserFrequencies基频和倍频Fundamentalandmultiples连续光纤激光ContinuousWaveFiberLasers激光在光纤中产生Laserlightiscreatedinthefiber可在连续波和脉冲波中使用Canbeusedinpulsedmod

7、easwellasCW可以被用于焊接和切割Canbeusedforweldingandcutting激光二极管光LaserDiodeLight激光二极管光LaserDiodeLight光纤Fiber脉冲YAG激光（焊接）PulsedYAGLasers(Welding)闪光灯开关产生脉冲Flashlampturnsonandofftocreatepulses光纤用于传送激光Fiberisusedtotransmitlaserlight闪光灯（光泵）FlashLamp(OpticalPump)全反镜100%