学科分类
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14 个结果
  • 简介:AnanalysistechniquecombiningRBSwithPIXEtechnologybyx-particlesincidentbeamwasconstructedandappliedtoanalyselightimpuritiesinheaviersubstrates.ItcanruninmeasuringRutherfordbackscatteringandX-rayspectrainrandomandchannelingmode,simultaneously.Beingusedtoanalysesulphuratomsim-plantedintoGaAssinglecrystals,thismethodisrelativelysimpleandquick-operating.Itisespeciallyusefulforanalysinglightimpuritiesinsemiconductorcompounds,optoelectronicandmicrowavematerials.

  • 标签: RBS PIXE CHANNELING mode ION IMPLANTATION
  • 简介:Developmentofweldingtechnologyofhydroelectricpowerequipment¥ZHENGBenying(DongfangElectricalMachineryWorks,SichuanDeyang(61800...

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  • 简介:Weldingtechnologyinoil-fieldconstructioninChina¥HOUXianzhong(DaqingOilField)Abstract:Thispaperintroducestheapplicationanddeve...

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  • 简介:DeformationtemperatureandpostdeformationannealingeffectsonseverelydeformedTiNialloybyequalchannelangularextrusionLIZhenhuaandCHENGXianhuaAbstractMicronTiNialloyblockswerefabricatedathightemperatureby

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  • 简介:Thetenacityofheat-affectedzone(HAZ)willdeclineandthesizeofgrainswillincrease,becauseoftheoverheatingonHAZwhensubmergedarcwelding(SAW)isusedtothickplatewithhighheatinput.TheshapingwillworsenwhenSAWisusedtothinplatewithhighcurrentathighspeed.AnewSAWtechnology,thepulseddirectcurrent(DC)automaticSAW,willbeputforwardinthispaperinordertoovercometheaboveshortcomings.Andapulsedcontrollerwithmicro-controllerunit(MCU)asthecore,nixietube(NT)andkeyboardastheman-machineconversationinterfaceisdeveloped.Themainfunctionsofthepulsedcontrollerincludetheoutputofpulsedweldingcurrentandtheworkingwithtwinwire.Theresearchhaswidelyprospectsinapplicationwithsignificantmeaningsintheoryandpracticalengineering.

  • 标签: 双丝电弧焊 脉冲控制技术 微控制单元 热影响区 焊接自动化
  • 简介:DevelopmentonmanufacturingtechnologyofrailwaylocomotiveandrollingstockindustryinChina¥WANGKejia(ChinaNationalRailwayLocomotiv...

  • 标签: China
  • 简介:ProblemsaboutsurfacemountingprocessforfinepitchdevicesandreasonsonsolderbridgingofLtypeleaddevicesweldedaredepicted.Bridgingmechanismandinfluencefactorsareanalyzedwithtwo-dimensionalgeometricmodel.Basedonthis,high-densitysurfacemounttechnology(SMT)forfinepitchLtypeleaddevicesheatedbyscan-ninglaserisraised.SurfacemountprocessforQFP208onprintedcircuitboard(PCB)isstudied.Theresultsoftestsarethatitisquitepossibletosolvethesolderbridgingofsurfacemountingforpitchdeviceswithscanninglaser-heat-ingmethod.

  • 标签: Surface MOUNT TECHNOLOGY (SMT) DEFECT BRIDGING
  • 简介:Thecharacteristicsoftemperatures,stressesandstrainsfieldshavebeenstudiednumericallyforatitaniumalloysheetweldedwithanimprovedgastungstenarcweldingmethod,inwhichatrailingspotheatsinkisintroducedtocontroltheweldingstressanddistortion.Theimpingingjetmodelisemployedtodescribetheintenseheattransferbetweenthecoolingmediaandthetopsurfaceoftheworkpiece.Theinfluenceofthedistancebetweenarcandheatsinkisinvestigated.Resultsshowthatthereisanidealrangeofdistance.Usingtheidealdistance,alowstressandnodistortionweldingstructurecanbederived.

  • 标签: 弧焊 热散应力 焊接技术 变形
  • 简介:Somepartswithcapillarytoplatejointhaveimportantapplicationinaerocraft.Vacuumelectronbeambrazing(VEBB)technologyisusedtorealizethisjointingwithcapillaries.Firstly3Dfiniteelementanalysismodelisbuiltinthispaperaccordingtothisspecialstructure.AndthenANSYSfiniteelementanalysissoftwareisusedtoanalyzebrazingtemperaturefieldatdifferentbrazingparameters.Thecalculationresultsshowthatthetemperaturefieldofsimulationhasgoodagreementwiththatmeasuredbyexperiment,whichprovesdependenceofthemodelbuiltinthispaper.Andalsoreferenceparameterscouldbeprovidedforrealbrazingprocessthroughcalculationinthismodel.BrazedjointofcapillarytoplatewithgoodperformanceisachievedusingVEBBtechnology.Theachievementofthestudywillbeappliedinaerocraftinthefuture.

  • 标签: 板快结合 真空电子束 铜焊接技术 有限元分析 温度场
  • 简介:WeldingresearchofA6N01S-T5aluminumalloyprofileforhigh-speedtrainwasdonebyusinglaser-MIGhybridweldingandMIGweldingindividually.Andtheweldappearance,weldingdistortion,mechanicalpropertiesofthejointsandmicrostructureswereanalyzed.Thetestresultsdemonstratedthathigh-efficientweldingfortheprofilecanbeachievedbyusinglaser-MIGhybridwelding,thespeedofwhichcanbeover3.0m/min.Theprocessinghadagoodgapbridgingability,evenifthegapofthebuttjointwasupto2.0mm,agoodweldappearancecanalsobegot.Whilethehybridweldingspeedwasgreaterthan2.5m/min,theweldingdistortionofthelaser-tandemMIGhybridjointswasjustabout33%ofthatoftheMIGjoints,buttheweldingefficiencywasover3timesofMIGwelding.Andtensilestrengthofthehybridjointswas85%ofthatofA6N01S-T5basemetal,9%higherthanthatoftheMIGjoints.Fatiguepropertieswastestedindividuallywithpulsedtensilefatiguemethodintheconditionof1×107lifetime.Thetestresultsdemonstratedthatthefatiguestrengthofthejointswasalittlelowerthanthatofbasematerial,whichcouldbeupto115MPa.Butthefatiguestrengthofhybridweldingjointswas107.5MPa,whichwas23%higherthan87MPaofMIGweldingjoints.

  • 标签: HIGH-SPEED TRAIN ALUMINUM alloy PROFILE laser MIG
  • 简介:在直径的200公里的AZ31合金营舍被扔的常规直接寒冷(DC)的三个不同过程生产,低频率的电磁的扔(LFEC)并且扔的低频率的电磁的颤动(LFEVC)分别地。微观结构,macrosegregation和AZ31合金营舍的机械性质上的LFEC和LFEVC的效果被调查。在扔的常规DC,AZ31合金营舍展出了粗糙的谷物(大约370m)和艾尔和Zn的严重分离。面对独唱,低频率的轮流出现磁场或一块低频率的电磁的颤动地在200公里AZ31营舍扔的DC期间适用,在AZ31合金营舍的谷物有效地被精制(大约210m)并且在营舍的艾尔和Zn的macrosegregation极大地被减少。而且,张力的力量,破裂延伸和当演员组AZ31合金营舍的坚硬被LFEC和LFEVC的过程相对由扔的常规DC的过程扔了那改进。

  • 标签: AZ31镁合金 铸造技术 机械性能 微观结构 钢坯 半连续