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简介：Theaccuratecalculationandmeasurementofweldingtemperaturefieldisanimportantpreconditionforweldingmetallurgicalanalysisandweldingprocesscontrolling.Inthispaper,theconformaltransformationisfirstlyusedtoanalyzetheweldingtemperaturefieldoffeatheredgedcylinder.Thecenterofthecylinderischosenastheoriginofcolumncoordinatesystem,andeverypointmaybeexpressedascomplexfieldvector.Thebranchisogonalitycounterchangesthelineparallelwiththefusionlineinhalf-infinitez-planetothecircleconcentricwiththefusionlineininfinitecylinder.TheLaplaceequationandPoisson'sequationstillkeepvalidity,sothetemperaturefieldequationcanbesolved.TheconformaltransformationandequationsolutionisprocessedbyMatlabprogramlanguage.Itshowsthattheobtainedanalyticalmodelingoftemperaturefieldforfeatheredgedcylinderbasedonconformaltransformationiseffectiveandaccurate.

简介：数字分析和模拟是一个有效工具开发先进生长技术并且为300公里并且在以外的硅晶体控制缺点类型，尺寸和密度。在现在的纸，在Czochralski(CZ)水晶生长配置的melt流动的数字分析，三维(3D)建模，模拟在磁场，当模特儿的逆和时间依赖者模拟下面融化流动被考察。最后，有试验性的大小的数字分析的比较被讨论。

简介：Mechanicalpropertiesofgalvannealed(GA)steelsheetusedforautomotiveexposedpanelandpredictedfailurephenomenonofitscoatinglayerwereevaluatedusingfiniteelementmethod.V-bendingtestwasperformedtounderstandbetterthefractureofcoatinglayerofGAsteelsheetduringplasticdeformation.Yieldstrengthofthecoatinglayerwascalculatedbyusingarelativedifferencebetweenhardnessofcoatinglayermeasuredfromthenano-indentationtestandthatofsubstrate.Tomeasureshearingstrengthattheinterfacebetweensubstrateandcoatinglayer,shearingtestwithtwospecimensattachedbyanadhesivewascarriedout.Usingthemechanicalpropertiesmeasured,aseriesoffiniteelementanalysescoupledwithafailuremodelwasperformed.Resultsrevealthatthefractureofcoatinglayeroccursinanirregularmannerattheregionwherecompressivedeformationisdominant.Meanwhile,aseriesofverticalcracksperpendiculartomaterialsurfaceareobservedatthetensilestressed-region.Itisfoundthat0.26-0.28oflocalequivalentplasticstrainexistsatthecoatingandsubstrateatthebeginningoffailure.Thefractureofcoatinglayerdependsonductilityofthecoatinglayerconsiderablyaswell.

简介：Alotofexperimentalmethodshavebeenbroughtforthtoassessthedynamiccharacterofthearcweldingpowersource,butuptonow,thisissuehasnotbeensolvedverywell.Inthispaper,basedonthefuzzylogicreasoningmethod,adynamiccharacterassessingmodelforthearcweldingpowersourcewasestablishedandusedtoanalyzethedynamiccharacteroftheweldingpowersource.Threedifferenttypesofweldingmachinehavebeentested,andthecharacteristicinformationoftheelectricalsignalssuchasre-strikingarcvoltage,lowweldingcurrentandsoonoftheweldingprocesswereextractedaccuratelybyusingaself-developedweldingdynamicarcwaveletanalyzer.Theexperimentalresultsindicatethatthismodelcanbeusedasanewassessingmethodforthedynamiccharacterofthearcweldingpowersource.

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简介：ThestoredenergyandtheenergyreleaseduringSPD(superplasticdeformation)ofaZn-5Alalloywerestudied.Thealloyafterrollingprocessgainsmorestoredenergy,andtheas-rolledspecimencanobtainmaximumelongationandminimumflowstresswithouthotholdingtreatmentbeforeSPD.ExperimentalresultsshowthatstoredenergyreleaseprocessisalongwithSPDprocessandisalsoanimpetustoSPD.Theas-rolledZn-5Alalloyhas48J/molstoredenergywhichwasmeasuredwithDSC(differentialscanningcalorimeter)andconformswelltothecalculatedvalue.Theas-rolledZn-5AlalloyafterSPDwithanelongationof2500%releases112J/molstoredenergy.Analysisshowsthatthestrainrateisindirectratiototherateofstoredenergyrelease.

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简介：ThispaperdealswithastudyonSnPbandlead-freesolderedjointreliabilityofPLCCdeviceswithdifferentleadcountsunderthreekindsoftemperaturecycleprofiles,whichisbasedonnon-linearfiniteelementmethod.Byanalyzingthestressofsolderedjoints,itisfoundthatthelargeststressisattheareabetweenthesolderedjointsandtheleads,andanalysisresultsindicatethatthevonMisesstressatthelocationslightlyincreaseswiththeincreaseofleadcounts.ForPLCCwith84leadsthesolderedjointswasmodeledforthreetypicalloading(273-398K,218-398Kand198-398K)inordertostudytheinfluenceofaccelerationfactorsonthereliabilityofsolderedjoints.Andtheestimationofequivalentplasticstrainofthreedifferentlead-freesolderalloys(Sn3.8Ag0.7Cu,Sn3.5AgandSn37Pb)wasalsocarriedout.

简介：AnimprovedmethodhasbeendevelopedforenrichinganddeterminingtraceIn,Pt,Sn,Co,Hg,Pb,Ni,Bi,Pd,CuandAginhigh-puritygallium.SamplewastreatedbyPDM（partialdissolutionofmatrix）withHCl（11mol/L）-HNO3（0.5mol/L）toasmallresidueofwhichGawasthenremovedbyextractionwith1mlisopropylether.TheconcentratedimpuritiesweredeterminedbyAESprocedure.Therecoveriesfortheele-mentsattherangeof0.02～0.2μgare95～103％;therelativestandarddeviationsfordeterminedimpuritiesoverarangeofn.10-7～n·10-8％are4.3～12％;thedetectionlimitofmostelementscanreachn·10-7～n·10-8％levelwiththeexceptionofHgandPt.Thismethodhasbeensuccessfullyusedtoanalyzemanysam-plessentbyfactoriesandinstitutes.

简介：Thispapermainlyconcentratedonthefeasibilityoffrictionstirweldingofdissimilarmetalofaluminumalloytocopper(T2)andapreliminaryanalysisofweldingparametersinfluencingonthemicrostructuresandpropertiesofjointwascarriedout.Theresultsindicatedthatthethicknessofworkpieceplayedanimportantroleintheweldingparameterswhichcouldsucceedinthefrictionstirweldingofdissimilarmetalofcoppertoaluminumalloy,andtheparameterswereprovedtobeanarrowchoice.Theinterfacialregionbetweencopperandaluminuminthedissimilarjointwasnotuniformlymixed,constitutedwithpartofincompletemixingzone,completemixingzone,dispersionzoneandthemostregion’sboundarywasobvious.Meantimeakindbandedstructurewithinhomogeneouswidthwasformed.TheintermetalliccompoundsgeneratedduringfrictionstirweldingintheinterfacialregionweremainlyCu9Al4,Al2Cuetc,andtheirhardnesswashigherthanothers.

简介：在在铝的Sc和Ti增加之间的精制谷物的效果的差别，不能被传统的理论实质地解释，小心地被学习。固体和分子的实验电子理论(EET)被采用计算Al3Ti和Al3Sc的原子价电子结构(VES)。结论能被得出在二合金Al-Ti和Al-Sc，不同原子价电子Al3Ti和Al3Sc和二个粒子的生长习惯的作为结果的差别组织，并且在粒子和矩阵之间的不同界面的电子密度根本上在铝上导致在Sc和Ti增加之间的精制谷物的效果的差别并且做Sr铝更好谷物精制。

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简介：Somepartswithcapillarytoplatejointhaveimportantapplicationinaerocraft.Vacuumelectronbeambrazing(VEBB)technologyisusedtorealizethisjointingwithcapillaries.Firstly3Dfiniteelementanalysismodelisbuiltinthispaperaccordingtothisspecialstructure.AndthenANSYSfiniteelementanalysissoftwareisusedtoanalyzebrazingtemperaturefieldatdifferentbrazingparameters.Thecalculationresultsshowthatthetemperaturefieldofsimulationhasgoodagreementwiththatmeasuredbyexperiment,whichprovesdependenceofthemodelbuiltinthispaper.Andalsoreferenceparameterscouldbeprovidedforrealbrazingprocessthroughcalculationinthismodel.BrazedjointofcapillarytoplatewithgoodperformanceisachievedusingVEBBtechnology.Theachievementofthestudywillbeappliedinaerocraftinthefuture.

简介：ThemicrostructuralevolutionandVickershardnessmeasurementintheweldingheat-affectedzone(HAZ)ofHD15Ni1MnMoNbCusteelfornuclearpowerstationwereinvestigatedbyGleeble-3180thermalmechanicalsimulator,andthesimulatedHAZcontinuouscoolingtransformationcurves(SH-CCT)weremeasuredsimultaneously.Witht_(8/5)increasingfrom3.75sto15000s,theproductwasobtainedmartensite,bainite,ferriteandpearlite,successively.TheresultofmicrostructureandVickershardnessintheheat-affectedzonewasingoodagreementwiththosemeasuredbySH-CCTdiagramwiththeheatinput16.2kJ/cmasanexampletoweldtheHD15Ni1MnMoNbCusteelpipeusingTIG/SMAW/SAWweldingmethods.

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