学科分类
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500 个结果
  • 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.

  • 标签: 功率源 脉冲等离子体 等离子弧焊 IGBT 表面处理 焊接
  • 简介:Aspectraldiagnosticsofcomplexareplasmausingmultiplespectralinformationofareself-emittingispro-posed.Thismethodisabletosimultaneouslydeterminecomponentdensities,thecorrespondingtemperatureandtheirdis-tributionsbyafewlineintensitiesmeasurent.Theprincipleofthemethodandtherelevantmeasuringsystemarede-scribed.Anequationsystemisestablishedforcomputationofthestatevariablesinareplasma.Anexperimentunderweldingareconditionismadeasanapplicationofthemethod.Theeffectsofprobableerrorsourcesonthemeasurementarealsoanalysed.

  • 标签: SPECTRAL DIAGNOSTICS COMPONENT DENSITIES WELDING ARC
  • 简介:Adistributedcontrolsystemisdesignedforplasmasprayingequipmentandtheconfigurationsofsystemsoftwareandhardwareisdiscussed.Throughfoundinganexpertdatabase,thesprayingprocessparametersareworkedoutandtheinitializationandcontrolofsprayingprocessarerealized.Theplasmasprayingsystemwiththiscontrolconfigurationcansimplifythesprayingoperation,improveautomationlevelofsprayprocess,andapproachtheexperiencecriterionassoonaspossible.

  • 标签: 分布式控制系统 等离子发散系统 铸造 自动化控制 单片机
  • 简介:Thekeyproblemfornumericalsimulationofplasmaarcwelding(PAW)processistodevelopasuitableandadaptivevolumetricheatsourcemodewhichreflectsthephysicalcharacteristicsofkeyholePAW.Tothisend,thekeyholegeometryunderdifferentPAWprocessconditionsmustbepredicted.Inthispaper,amathematicalmodelfordeterminingthekeyholeshapeisdevelopedwithconsideringthemassandmomentumconservationofthein-keyholeplasmajetaswellasthepressureequilibriumattheplasmajet/liquidmetalboundary.AsuitableheatsourcemodelrelatedtothekeyholeshapeisappliedtothecalculationofPAWwelddimensions.Thepredictedresultsareingoodagreementwiththeexperimentalones.

  • 标签: 等离子弧焊 小孔 几何结构 数值分析
  • 简介:Athree-dimensionalsimulationmodelfortheplasma-MIGweldingprocess,whichtakestheinteractionbetweentheplasmaarcandMIGarcintoaccount,ispresentedandthequasi-steadytemperaturefieldsontheworkpiecearecalculatedwiththemodel.The10mm-5A06aluminumalloyisweldedandthetemperaturefieldsaremeasuredwiththethermoelectriccouple.Thesimulationresultsandmeasuredresultsshowthatthebiggestdeviationofpeaktemperaturebetweenthemisbelow20℃,whichindicatesgoodcoincidencebetweenthesimulationandmeasurement.

  • 标签: 等离子体-MIG焊接 温度场 热电偶 热源模型
  • 简介:Thecombinedquadraticorthogonalregressionmethodofexperimentdesignwasemployedtoexploretheeffectsofprocessparametersofplasmanitridingoftantalumsuchastotalpressure,temperatureandoriginalhydrogenmolarfractiononthehardness,roughnessandstructureofnitridingsurfaces.Theregressionequationsofhardness,roughnessandstructureweregivenaccordingtotheresultsofregressionandstatisticanalysis.Andthediffusionactivationenergyofnitrogenintantalumonplasmanitridingconditionswascalculatedaccordingtotheexperimentaldataofhardnessofplasma-nitridingoftantalumvstimeandtemperature.Thediffusionactivationenergycalculatedbelongsto(155.49+10.51)kJ/mol(783-983K).

  • 标签: 渗氮等离子体 温度 压力 正交回归法 扩散活化能
  • 简介:MechanicallyactivatedW-Cupowdersweresinteredbyasparkplasmasinteringsystem(SPS)inordertodevelopanewprocessandimprovethepropertiesofthealloy.Propertiessuchasdensityandhardnessweremeasured.ThemicrostructuresofthesinteredW-CualloysampleswereobservedbySEM(scanningelectronmicroscope).Theresultsshowthatsparkplasmasinteringcanobviouslylowerthesinteringtemperatureandincreasethedensityofthealloy.Thisprocesscanalsoimprovethehardnessofthealloy.SPSisaneffectivemethodtoobtainW-Cupowderswithhighdensityandsuperiorphysicalproperties.

  • 标签: 钨铜合金 粉末冶金 机械活化 火花等离子体烧结
  • 简介:Inthispaper,laserinducedplasmasignalswereanalyzedduringkeyholeweldingthroughthreemethods.Accordingtotheresults,therelativitybetweenopticalandacousticsignalsofplasmaisshownwhenweldsareinfull-penetration,orpartial-penetrationandnon-penetration.

  • 标签: 激光焊接 等离子体 光学信号 声学信号
  • 简介:Keyholeplasmaarcweldingexperimentsareconductedtomeasuretheweldgeometryandpenetrationatdifferentmomentsduringtheinitialphasefromignitingarctoquasi-steadystate.Indirectinformationonkeyholeformationandevolutioninplasmaarcweldingcanbeextractedbasedontheweldmacrophotographatcrosssection.Ithaslaidfoundationtoverifythemathematicalmodelsofkeyholeplasmaarcwelding.

  • 标签: 锁眼 等离子体电弧焊 熔深 实验测定
  • 简介:Anewkindofcontrolsystemforkeyholeplasmaarcwelding(K-PAW)wasdevelopedbasedonthecomputerandtheGraphicsLanguage-LabVIEW.Itcansetandoutputtherequiredcurrentwaveformswithdesireddecreasingslopessothatthecorresponding'openingandclosing'ofkeyholecanoccurperiodically.Withthiscontrolstrategyofweldingcurrentwaveforms,theworkpieceisfullypenetratedwhilenoburn-throughoccurs.Keyholeplasmaarcweldingexperimentswereconductedtoverifythestabilityandreliabilityofthedevelopedsystem.

  • 标签: 等离子体电弧焊 锁眼 计算机控制系统 LABVIEW
  • 简介:Sinceamorphousalloyshavewiderapplication,theycannotbefabricatedusingtheconventionalcoolingvelocity.ThebarmaterialplasmasprayingisadoptedtofabricateFebaseamorphousalloyinthisinvestigation.Thecrystallizationdegree,microstructure,micro-hardness,composition,crystallizationtemperatureoftheamorphousalloyandtheflyingrulesoftheatomizedparticlesintheprocessoftheplasmasprayaretested.Theresultsshowthatthealloypreparedhasthehighamorphousdegreeandhomogeneousmicrostructure,micro-hardnessandthecrystallizationtemperaturecanreach1187HVand531℃respectively.Theatomizationisverywellduringtheprocessofplasmaspraying;andthereishighthermalgradient,thecoolingvelocityreaches6.07×107K/s.

  • 标签: 非定形合金 棒材 等离子体喷射 焊接