活性元素镁对铝合金真空钎焊接头性能的影响

:2006-06-30:(K1101020302)1,2(1.,230031;2.,210016):3A21,,,,235g/m3,78MPa;,Mg2Si,235g/m3,0.06mm;325,:;;:TG454:A:0253-360X(2007)07-061-040Al2O3,2000,,,Miller,[1]1962[2],,,,,,;,Al-Si-Mg,,[3],,,,,Al-Mg,,,,10-3Pa,Bares[4],Al-Mg[5],,,11.1,3A216mm60mm50mm;BAl86SiMg1.2VBF8510,710-4Pa;1228720077TRANSACTIONSOFTHECHINAWELDINGINSTITUTIONVol.28No.7July200710-3Pa;1;4;0.67Pa/h;0.2MPa1.3,,1DCS5000,PME,0.5%1Table1KeybrazingparameterT/t/minBAl86SiMg605122.111Fig11RelationbetweenMgdinsityandshearstrengthofbrazedjoints,2,34Al-Mg-Si,,,2,3,4,,240.11mm,30.06mm,Mg2Si,1.731,22202g/m3Fig12Microstructureofbrazedjoint(Mgdinsity2202g/m3)3235g/m3Fig13Microstructureofbrazedjoint(Mgdinsity235g/m3)423g/m3Fig14Microstructureofbrazedjoint(Mgdinsity23g/m3),Mg2Si,2.2,,,,55,325,,,325(6),62285Fig15RelationbetweenMgvolatilizationamountandheatholdingtime530,325,,,,6Fig16Relationbetweenelementpressureandtemperatureofvapoar,,,,[6]10Pa,,0.007g/L,,2[7]6,,,210-2PaTable2Volatilizationtemperaturesofdifferentelementsin10-2PavacuumconditionT/T/T/Cd180Ag848Fe1194Zn248Sn922Ti1249Mg335Cr992Ni1257Li377Ge996Pd1271Bi536Be1029Co1362Pb546Cu1035V1584In746Si1115Mo2093Mn790B1140Nb2355Al808Au1190W27602.3,,,,,,,,,,,[7],Al-Si-Mg,,1.5%2%,,,,,,,,3(1),7,:63235g/m3,78MPa(2),Mg2Si,235g/m3,0.06mm(3)325,:[1],.[M].:,1999.[2].[J]..,1984,28(5):12-15.[3].[M].:,1989.[4]Bares.Ovenforthevacuumbrazingofaluminum[M].StreetCloud,Florence,1989.[5].[J].2,1983,47(9):22-29.[6].22[J].,1996,18(6):2-4.[7],.[M].:,2005.:,,1970,,10Email:[e-mail][60]:[1]ZhangYM,LiguoE,KovacevieR.Activemetaltransfercontrolbymonitoringexciteddropletoscillation[J].WeldingJournal,1997,76(11):458s-469s.[2],,,.[J].,2005,26(2):37-40.[3],,,.[J].,2003,23(4):1-4.[4]CastlemanKennethR.Digitalimageprocessing[M].Prentice.Hall,1996:178-193.[5]ValkamaM,RenforsM.Anovelimagerejectionarchitectureforquad2ratureradioreceivers[J].IEEETrans.CircuitsSystII,2004,51:61-68.[6]BradshawLA,WikswoJP.Spatialfilterapproachforevaluationofthesurfacelaplacianoftheelectroencephalogramandmagnetoencepha2logram[J].AnnalsofBiomedicalEngineering,2001,29(3):202-213.:,,1980,3Email:[e-mail]:magnesiumalloy;longitudinalmagneticfield;weldedjoint;mechanicalpropertiesLinearimageprocessingofpulseGMAWdropletphotosbasedonfrequencydomaincalculationWANGGuangwei,CAIYan,HUAXueming,WUYixiong(SchoolofMaterialsScienceandEngineering,ShanghaiJiaotongUniversity,Shanghai200030,Chi2na).p57-60,64Abstract:Basedonmicrofocushighspeedphotographysys2tem,therearestilllotsofambientnoiseanddiffractionstripescausedbyweldingdustandarclightinthephotosofthepulseGMAW(gasmetalarcwelding)droplet,whichmakethemeasure2mentofthedropletgeometry,neckingandothercharacteristicofdropletsquantificationallymoredifficult.Toensurethepropertyoftheimagebeforeandafterprocessinginvariably,thelinearimageprocessingalgorithmincludingthedesignedlowpassattenuatorandGaussianlowpassfiltercombinedwithgraylevelmappingandLaplacianadditionwasproposedbasedonfrequencydomain.Theresultsofexperimentsshowthecombinationoffrequencydomaincal2culationwithlinearimageprocessingcanobtaintheclearphotosofpulseGMAWdropletshapewhichseparatedfromnoisybackground.Therealityandavailabilityofthephotosisensured.ThismethodofalsoprovidesthepossibilityforpulseGMAWprocesshighprecisionquantificationallyanalysis.Keywords:pulsegasmetalarcwelding;dropletphotos;frequencydomainInfluenceofactiveelementMgonjointpropertiesofaluminumalloyvacuumbrazingLIANGNing1,SHENGYifu2(1.No.38RezearchInstituteofChinaElectronicsTechnologyGroupCorpora2tion,Hefei230031,China;2.SchoolofMateriulsScienceandEn2gineering,NanjingUniversityofAeronautics&Astronautics,Nan2jing210016,China).p61-64Abstract:Ashighpuremagnesiumofthesolidstatewillvolatilizewhenitisheated,theinfluenceofactiveelementMgcon2tentontheperformanceofbrazedjointinthevacuumwasresearchedasbrazingaluminumalloy3A21.Themechanicalpropertiesandmi2crostructureofthejointwereanalyzedwithuniversaltestingmachineandmicroscope.BycomparisonofshearstrengthofdifferentbrazedjointswiththreekindsofMgcontentsitisfoundthatthestrengthisashighas78MPawhentheMgcontentreaches235g/m3.Themi2crostructuresindicatethatthereinforcingphaseisMg2Siandthewidthofbrazingzonewastheleast,0.06mm,whentheMgcontentis235g/m3.TheMgcontentcanbecontrolledinthehearththroughobtainingthestayingtimeover325ofdifferentproducts.Keywords:activeelement;vacuumbrazing;mechanicalpropertiesWaveletdetectionofshortcircuitsignalinCO2arcweldingbasedonDSPTIANSongya,WUDongchun,SUNYe,FUWeiliang(SchoolofMechanical&ElectricalEngineeringHehaiUni2versity,Changzhou213022,Jiangsu,China).p65-68Abstract:AccordingtoarcvoltageofCO2areweldingchar2acteristic,thefeasibilityofapplicationwavelettransformtheorytothedetectionofshort2circuitsignalinCO2arcweldingandputtingsignalofshortcircuitcontrolistested,andfrequencyspectrumoftrueshortcircuit,falseshortcircuitandnoisearealsoanalyzed.Themechanismofremovingfalseshort2circuitsignalandnoisesignalbywavelettransformisanalyzedbytheoryanalysisandmathematicsfor2muladeduction.Differentwav