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简介：Inthepresentpaper,thegraphicalmethoddeterminationofoptimalweldingparametersofGMAWisdescribed.Somequalitycomplexcriteriathataretheratioofweldsizeshavebeenproposed.Thesecriteriaallowoptimizingtheshapeoftheweldmetalzone,reducingthelikelihoodofhotcracksformation,andreducingthestressconcentrationoftheweldatthetoe.Intheproposedmethodology,theearlierdescribedequationsconnectingtheweldingparametersandthewelddimensionsofmildandlow-alloysteelsareexplored.Determinationoftheoptimalweldingparametersiscarriedoutgraphicallytakingintoaccountthevarianceoftheweldingparameters.Anexampleofusingtheproposedmethoddestinedtodeterminetheoptimumweldingparametersisprovided.Itisshownthatitsaccuracyissufficientlygoodforapracticalapplication.

简介：Asadepositiontechnology,gasmetalarcwelding(GMAW)hasshownnewpromiseforrapidprototypingofmetallicparts.DuringtheprocessofmetalformingusingthearcofGMAW,lowheatinputandstabledroplettransitionarecriticaltohighqualityfiguration.TheeffectsofvariousprocessingparametersonfigurationqualitywerestudiedintheexperimentofGMAWrapidprototypingusingthewireofER50-6,includingweldingvoltage,wirefeedingrate,weldingspeedandsoon.TheoptimalparametersforER50-6areobtained.Simultaneously,itisverifiedthattherapidprototypingpartswithfavorablestructuresandqualitycanbeachievedundertheconditionsoflowheatinputandstabledroplettransition.

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简介：Theelectronbeamwelding-brazingbeingusedtojoin5A06AlalloytoTC4Tialloydecreasestheformationofbrittleintermetalliccompound.Experimentswerecarriedouttostudytheinfluenceofelectronbeamweldingparametersonthetensilestrengthofwelds,basedonanorthogonaltestandanalysismethod.Theweldingparametersincludebeamcurrent,weldingspeed,scanningfigure,scanningfrequency,figuresize,beamoffsetandfocuscurrent.Theoptimumparametersfor3mm5A06Alalloyand2mmTC4alloywereasfollows:accelerationvoltagewas60kV,beamcurrentwas11mA,weldingspeedwas600mm/min,focuscurrentwas0mA,scanfigurewasO,scanningfrequencywas1000Hzandbeamoffsetwas0.5mm.Theresultsshowthatthejointswerewithgoodappearanceandqualityweldedbytheoptimumparameters.ThesuccessfuljointscouldbegainedandthemaximumtensilestrengthofAl/Tidissimilaralloyjointscouldbeupto222.61MPausingelectronbeamwelding-brazing.

简介：Theeffectsofprocessparametersonthemicrostructuralevolution,includinggrainsizeandvolumefractionoftheαphaseduringhotformingofaTC6alloywereinvestigatedusingcompressiontests.Experimentswereconductedonthematerialwith(α+β)phasesatdeformationtemperaturesof800,860,920,and950°C,strainratesof0.001,0.01,1,and50s-1,andheightdirectionreductionsof30%,40%,and50%.Afterreachingapeakvaluenear920°C,thegrainsizeandvolumefractiondecreasewithfurtherincreaseofdeformationtemperature.ThestrainrateaffectsthemorphologiesandgrainsizeofαphaseoftheTC6titaniumalloy.Atalowerstrainrate,theeffectofthestrainrateonthevolumefractionisgreaterthanthatatahigherstrainrateundertheexperimentalconditions.Theeffectsofthestrainrateonthemicrostructurealsoresultfromdeformationheating.Thegrainsizeoftheαphaseincreaseswithanincreaseinheightdirectionreductionafteranearlydrop.Theeffectofheightdirectionreductiononthevolumefractionissimilartothatofthegrainsize.AlloftheopticalmicrographsandquantitativemetallographyshowthatdeformationprocessparametersaffectthemicrostructureduringhotformingoftheTC6alloy,andacorrelationbetweenthetemperature,strain,andstrainrateappearstobeasignificantfuzzycharacteristic.

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简介：TheAl-alloyarc-weldingshapingsystembasedonarc-weldingrobotisestablished,andtheAl-alloyshapingmanufactureisrealizedwiththeDC(directcurrent)gasmetalarcwelding(GMAW).TheresearchindicatesthatthemetaltransfertypeofDCGMAW,heatinputandtheinitialtemperatureoftheworkpiecegreatlyaffecttheAl-alloyshapingbasedonarcweldingrobot.Onthepenetration,theweldwidthandthereinforcement,theinfluenceofweldingparametersisanalyzedbygeneralizedregressionneuralnetwork(GRNN)fitting.

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简介：8月31日，记者从上海海关获悉，在我国对出口退税政策进行调整、退税率整体下调的影响下，半年多来，该口岸出口商品结构已明显改善：一般商品出口减缓，科技含量高的商品出口得到大幅提升，加大科技投入、增加产品附加值的出口方向也随之愈加明朗。

简介：ThesoftwareofSYSWELDwasusedtobuildmodelandsimulatethermalcycleofin-serviceweldingontoactivegaspipeline.Influenceofpipediameter,wallthicknessandheatinputonthermalcyclewasstudied.Theresultsshowthatt8/5,t8/3andpeaktemperatureofinnersurfacedecreasewhenwallthicknessincreasesfrom5mmto12mm.Butt8/1willincreaseswiththeincreaseofwallthicknessandwilldecreaseafterthewallthicknessislargerthan7mm.Pipediameterhaslittleinfluenceonthermalcycleandthatinfluencecanbeignoredwhenpipediameterisgreaterthan273mm.t8/5,t8/3,t8/1andpeaktemperatureofinnersurfacewillincreasewiththeincreaseofheatinput.

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简介：尽管需求疲软，但美国8月的废铝出口量仍略有上升，其中对国际市场影响日益增大的中国起了很大作用。在美国前8个月的废铝出口中，中国（包括香港）占了其总出口量108．1万吨的70．4％，比去年同期的164．7吨增加了47．5％。今年8月，美国废铝总出口为16．36吨，