简介：AprototypeofPulsedPlasmaArcCladdingsystemwasdeveloped,inwhichsinglepowersourcesuppliesbothtransferredplasmaarc(TPA)andnon-transferredplasmaarc(N-TPA).BothplasmasworkinturninahighfrequencycontrolledbyanIGBTconnectingnozzleandworkpiece.TheworkingfrequencyofIGBTrangesfrom50～7000Hz,inwhichtheplasmascanworkinturnsmoothly.Higherthan500HzofworkingfrequencyissuggestedforpromotionofcladdingqualityandprotectionofIGBT.DragphenomenonofTPAintensifiesasthefrequencygoesup,whichtendstoincreasethecurrentproportionofTPAandsuppressN-TPA.TheoccupationratioofIGBTcanberegulatedfrom5%～95%,whichbalancesthepowersuppliesofbothplasmas.Anoccupationratiohigherthan50%givesadequateproportionofarccurrentforN-TPAtopreheatpowder.

简介：Apulsedcurrentisintroducedintothetraditionalcoaxiallasercladdingprocesstodecreasetheporosityofthecladdinglayer.Themagnetocontractionforcecausedbypulsedcurrentexertedonthemoltenpoolsqueezesthegasoutandcompensatestheshrinkageduringmoltenpoolsolidification.Asaresulttheporosityofthecladdinglayerisdecreasedtoanextremelylowdegree.Simultaneously,thegrainofthecladdinglayerisfinerwiththeaddedsupercoolingdegreewithpulsedcurrent.Themicrohardnessofanequiaxedzoneinthecrosssectionofacladdinglayeralsoincreases.

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简介：The304stainlesssteelstripsweredepositedonelayeroncarbonsteelbasemetalbyelectroslagstripcladding(ESC)andsubmergedarccladding(SAC),respectively.ThesolidificationmicrostructureofESCmetalwasanalyzedbytheopticalmicroscopy,scanningelectronmicroscopeandenergydispersivespectroscopy.Thecorrosionresistancestudiesofstripcladdingmetalswerecarriedoutin10%oxalicacidelectrolyticetchingtest.TheresultsshowedthatthecladdingmetalobtainedbyESCpresentedlowcontentofC,highcontentofCrandenoughalloyingelementofNiinthechemicalcomposition.ThetransitionzoneofESCwithsmallwidthwasalmostparallelwiththebasemetal,leadingtoalowerdilution.Therearethreetypesofsolidificationmodes(A→AF→FA)occurredintheESCmetalduetothedecreaseofcoolingrateanddegreeofdilutionfromthetransitionzonetothetopofESCmetal.Asaresult,themicrostructureofESCmetalexhibitedmainlyaustenitewithasmallamountofferrite,contributingtoachievementofbettercorrosionresistance.

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简介：Heathandlinghasbeenasignificantproblemofthehighpowerfiberlasersystemsastheoutputpowerincreasesrapidly.Claddingpowerstripper(CPS)whichisusedtodealwiththeunwantedopticalpowerandlightisrequiredforhighercoolingability.Sothemethodsofstrippingtheunwantedlightattractedmuchattentionrecently,andthethermaleffectisgiven.However,fewinvestigationsfocusonthedissipationoftheheatconvertedfromtheunwantedlight.Inthispaper,anapproachofactivecoolingforCPSisdemonstrated.ThisisachievedbyusingmicrochannelcoolingtechnologyinheatsinkinginCPStoimprovetheefficiencyofheatexchange.InordertoexplainthemechanismofCPSthefunctionofitandconsistenceofcategoriesoftheunwantedlightaredetailedfirstly.Thenmicrochannelheatsinkingisproposedandverifiedbytheheatexchangetheory.Atlast,thedesignoftheCPSwithmicrochannelheatsinkingisshownandfollowingexperimentisconducted.Thefinaltemperatureofthedevicewith1000WcladdingpowerwasdemonstratedatlasttoverifytheabilityofheatdistributionoftheCPScomponent.ThissuggeststhattheseCPSscanbeusedtostripeathousandofwattsoflightinhighpowerdoublecladdingfiberlasers.

简介：Anewgratingstructurewithcladdingetchedasthesinusoidalfunctionalongthelengthdirectionisintroduced.Thecladdingareaofthegratingvariesasthesinusoidalfunctionalongfiberaxes.Thecoupledmodetheoryisusedtoanalyzeitsperformance.Comparedwiththelinearlychirpedgrating,thenewstructureexhibitsanidealboxspectrumwithsteepedgeswhenthetensionisappliedonthegratingsintwodifferentways.ForthetypeBgrating,withouttensionafterwriting,ithasabiggerbandwidthutilization(BWU)thanthatofthetypeAgratingwithtensionafterwriting.ComparedwiththetypeAgrating,thetypeBoneismoreadaptableinfiber-opticcommunicationsandsensorsystems.

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简介：ByaddingmixtureofZrO2andcarbon,aZr-enhancedcompositecoatingwasproducedontoanAISI1045substratebylasercladding.Themicrostructureandphaseformation,microhardnessandwearresistanceofthecompositecoatingwerestudied.Theexperimentalresultsindicatethatthecompositecoatingwithmetallurgicalbondingtosubstrateconsistsof7-Ni,massiveceramicparticlesofZrC,NiZra,NiTZr〉（Fe,Ni）23C6andF%C.Theinsitu-synthesizedZrCparticlesareuniformlydispersedincompositecoating,whichrefinesthemicrostructureofcompositecoating.WithdifferentZrO2andcarbonaddi-tions,thepropertiesareimproveddifferently.Finally,thefineinsituZrCparticlesimprovethemicrohardnessofcompositecoatingtoHVo.2650,whichisnearly2.7timesthatofNi25coating.Also,thecompositecoatinghasanadvantageinwearresistance;itoffersbetterwearresis-tancewhenmoremixtureofZrO2andcarbonwasaddedinnickelalloys.

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简介：钡锶铝矽酸盐(BSAS)和Si/BSAS涂层经由一个二拍子的圆舞激光cladding过程在C/SiCcomposites的表面上被制作。微观结构，机械性质，和样品的水蒸汽腐蚀行为被调查。BSAS涂层被发现紧被结合到底层和仅仅一些毛孔，microcracks被观察。硅中间层的介绍被揭示减少热应力并且支持在激光cladding过程期间形成的缺点愈合。为了评估腐蚀抵抗，BSAS和Si/BSAS-coated，C/SiCcomposites暴露于50%H2在1250敢椠?慦桳潩的O和50%O2吗？

简介：ZM5镁合金上的preplacedAl+红外粉末的激光cladding被执行提高ZM5镁合金的腐蚀抵抗。一冶金契约在涂层/底层接口被获得。激光cladded样品的腐蚀潜力(Ecorr)是对未经治疗的ZM5底层的积极的169mV，当腐蚀电流(Icorr)低大约一个数量级时。激光cladded样品不同于未经治疗的ZM5底层，在极化阴谋显示出一个被动区域。沉浸测试证实激光claddedZM5样品的腐蚀电阻显著地在3.5wt.%NaCl答案被提高。在cladding层和快速的稳固的特征形成的AlIr，Mg17Al12，和艾尔的Al富有的阶段被贡献涂层的改进腐蚀行为。

简介：Inordertosolvethehigh-priceandshort-lifetimeproblemsofthecutterofagriculturalmachinery,andimprovethewearresistanceofthecutter,theTiCN/FemetalceramiccompositecoatingwaspreparedonthesubstrateofQ235steelbyreactionnitrogenarccladdingtechnique.ThemixturepowderoftitaniumandgraphitewaspreplacedontheQ235steelsurfaceafterintensivemixingbyplanetaryballmillandgluingwithstarchbinder.Themicrostructureandphaseofthecoatings,interfacebehaviorbetweencoatingsandthesubstratewereinvestigatedbyscanningelectronicmicroscopeandX-raydiffractometer.Themicro-hardnessdistributionofthecoatingsectionwastestedbymicro-hardnesstester.Frictioncoefficientandwearweightlossweremeasuredbyabrasionmachine.Wearingsurfacemorphologywasinvestigatedbyscanningelectronicmicroscope.TheresultsshowthatanexcellentbondingbetweenthecoatingsandtheQ235steelsubstrateisensuredbythestrongmetallurgicalinterfaceandphaseofthecoatings.ThecoatingsaremainlycomposedofTiCN.Thehighestmicrohardnessofthecoatingsreaches1089HVO.2,whilethemicro-hardnessofQ235steelsubstrateisonlyabout286HVO.2.Theanti-abrasivetestresultsshowthatthewearresistanceofthecladdingcoatingisbetterthanthatofquenchedandtempered65Mnsteelwhichisoftenusedascutterofagriculturalmachinery.ThefieldtestresultsshowthattheTiCN/Femetalceramiccompositecoatingpreparedbyreactionnitrogenarccladdingisfeasibletothemanufactureandremanufactureofthecutterofagriculturalmachinery.

简介：TN2412006064910液体物质中的空化现象实验研究=Experimentalresearchoncavitationbubbleinwater[刊,中]/赵瑞(南京理工大学应用物理系．江苏,南京(210094)),徐荣青…//光电子·激光．—2006．17(5)．—629—633采用自行研制的光偏转测试系统对强激光诱导液体物质的空化现象进行了实验研究,实验得到了激光等离子体冲击波传播规律和空泡的动力学特性。结果表明,激光等离子体冲击波在其传播过程中迅速衰减为声波；激光空泡的最大泡径随脉动次数增加依次减小,而收缩的最小泡径则由腔内含气量决定。图7参11(严寒)

简介：EffectsofMo,Nb,Tionmechanicalpropertiesandcorrosionresistanceof22.5%Crferriticstainlesssteelwereinvestigated.TheresultsshowthatMoexistsinferriticstainlesssteelmainlyinthesolutiontreatmentcondition,anditcanenhancesteel’sstrengththroughsolidsolutionstrengthening.InTi+Nbdual-stabilizedferriticstainlesssteel,thesteel’stoughnessdecreasesobviouslybecausecoarseTiNparticlesformandsomemetalliccompoundsprecipitatealongthegrainboundaries.InNbsingle-stablizedferriticstainlesssteel,NbexistseitherinthesolutiontreatmentconditionorintheformofdispersedprecipitatesNb(C,N),whichwillactasthenucleiofprecipitationofthefineσphase.Asaresult,theprecipitationofthecoarseσphasealongthegrainboundarycanbeinhibited,leadingtosignificantimprovementinsteel’stoughnessatalowtemperature.Basedonthese,highcorrosion-resistantferriticstainlesssteelB445Rwasdevelopedforthebuildingcladdingsystem.TestresultsshowthatB445Rhasasuperiorcorrosionresistancetoaustenitic316Linchloridesolution.Besides,ithasagoodformingpropertyandweldability.Allthesemakeitanidealdecoratingmaterialforthebuildingcladdingsysteminseverecoastalregions.

简介：P225.22005010205基于CPLD的脉冲激光测距飞行时间测量=MeasurementofflighttimeforpulsedlaserrangingbasedonCPLD[刊,中]／杨成伟(清华大学电子工程系．北京(100084))．霍玉晶…∥激光与红外.-2004．34(2).-106-108研制了基于CPLD的脉冲激光测距飞行时间测量系统。CPLD的使用提高了激光测距仪的精度,并且可灵活修改设计,使同一硬件系统可用于不同类型的脉冲激光测距仪的飞行时间测量。此系统结构简单,体积小,可靠性高,非常适合高性能手持式脉冲激光测距仪。图2参5(杨妹清)

简介：TIGweldingwasusedtodepositCo-8.8Al-9.8W-0.2Bsuperalloyon304austenitestainlesssteel.Theformfactorofweld,dilutionratio,microhardness,microstructureanddistributionofalloyingelementswereinvestigated.Themicrostructureofcladdinglayerwasmainlyhypoeutectic.Theprimaryphaseswerecobalt-richsolidsolution.Theeutecticphasewascomposedofcobalt-richsolidsolution,Co6W6CandCoCx.Whentheboroncontentincreasedfrom0.2%to0.5%,thedilutionratiodecreased,theprimaryphasebecamecoarseandthemicrohardnessdecreased.Whentheboroncontentwasfrom0.5%to2%,thedilutionratioandmicrohardnessincreasedobviously,buttheprimaryphasewasrefined.ThehardphaseofCo-8.8Al-9.8Wbecamerefinedandtheamountwasraised,andtheperformanceofcladdinglayerwasimprovedwithappropriateboronincrease.

简介：AnoverlaycoatingmaterialwasdepositedonasinglecrystalsuperalloySRR99bylasercladding.Themicrostructureandoxidationbehaviorofthiscoatingwasinvestigatedthroughscanningelectronmicroscopy(SEM)andX-raydiffraction(XRD).Theresultsindicatedthatalthoughthecompositionofthecoatingwaschosenbasedontheγ'compositioninReneN5superalloy,theprimarysolidificationphaseofthiscoatingduringlasercladdingwasγ-Ni.Furthermore,underthelasercladdingcondition,fineparalleldendritesgrewepitaxiallyinthecoatingfromthesubstrate,indicatingthesinglecrystalstructureofthesubstratewasreproduced.WhenthesinglecrystalMCrAlYcoatingwasoxidizedat1000,bothB-AI2O3and(Y-Al2O3formedduringinitialoxidationprocess.Astheoxidationtimeproceeded,thepreseneeof0-Al2O3facilitatedtheformationofNiAl2O4spineloxide.Oncethespinelwasobserved,itflourishedandinducedsomeporosityinthescale.Whenthescalethicknessincreasedto6-7μm,largeareaspallationofthescalebegan.

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