简介:InordertocontrolthesizeanddistributionofthehighconductiveFe2PinLiFePO4/Fe2Pcomposite,twodifferentcoolingrates(Fast:15℃·min-1,Slow:2℃·min-1)wereemployedaftermechanicalalloying.Thedischargecapacityofthefastcooledwas83mAh·g-1andtheslowcooled121mAh·g-1.TheparticlesizeofthesynthesizedpowderwasexaminedbytransmissionelectronmicroscopyanddistributionofFe2Pwascharacterizedusingscanningelectronmicroscopy(SEM).Inaddition,two-stepheattreatmentwascarriedoutforbetterdistributionofFe2P.X-raydiffraction(XRD)andRietveldrefinementrevealthatLiFePO4/Fe2Pcompositeconsistsof95.77%LiFePO4and4.33%ofFe2P.
简介:Anewintelligentcontrolmetholforweldingpositionerispropsed.ApplyinganimprovedfuzzycontrollerandavariablePIDcontroller,atwo-modeintelligengcontroller(TMICC)isdsignedonbasisoffuzzylogicadnrules.Thesimulationandexperimentalresultsshowthatthiscontrolsystemcanobtainbetterdynamicandstaticcharacteristics.
简介:Anewkindofcontrolsystemforkeyholeplasmaarcwelding(K-PAW)wasdevelopedbasedonthecomputerandtheGraphicsLanguage-LabVIEW.Itcansetandoutputtherequiredcurrentwaveformswithdesireddecreasingslopessothatthecorresponding'openingandclosing'ofkeyholecanoccurperiodically.Withthiscontrolstrategyofweldingcurrentwaveforms,theworkpieceisfullypenetratedwhilenoburn-throughoccurs.Keyholeplasmaarcweldingexperimentswereconductedtoverifythestabilityandreliabilityofthedevelopedsystem.
简介:Thegrainsizecontrolofthetungstenpowderisessentialforhighqualitytungstenproductsmaking.Basedonthestudiesonthehydrogenreductionprocessoftungstenoxide,amicrocomputersystemisintroducedtothereductionprocessparameterscon-trol.Themicrocomputerprocesscontrolsystem,whichisnowrunninginZhuzhouTungstenandMolybdenumMaterialsPlant,controlstheprocessparametersincludingthetemperatureofthereductionfurnaceandthepressureofhydrogen.Italsocontrolsamechanicalpusherwhichpushstheboatschargedwithbluetungstenoxideintothefurnacetubes.Someofthetechniqueprob-lemsappearedinthereductionprocessandtheprocesscontrolareanalysedinthispaper.Theresultoftheexperimentisalsogiven.
简介:通过化学沉积法制备Ni-P、Ni-Mo-P单镀层以及与其成分相同的Ni-P/Ni-Mo-P双镀层。采用纳米压痕法和AFM分析测量镀层表面和截面的残余应力,并用电化学法评估镀层在10%HCl溶液中的腐蚀行为,以获得镀层残余应力与腐蚀行为之间的关系。结果表明:Ni-P单镀层和Ni-P/Ni-Mo-P双镀层表现为残余压应力,分别为241和206MPa;Ni-Mo-P单镀层呈现出257MPa的残余拉应力。残余压应力阻止镀层中孔洞的生长,保护镀层的完整性。Ni-P/Ni-Mo-P双镀层比它们的单镀层具有更好的耐蚀性。此外,镀层的应力状态影响其腐蚀形式。
简介:Aimingattheweldingconditionofspacecomplexseamisuncertainandtheintelligenceofweldingrobotisunideal,atwo-wheeledmobilerobotisdeveloped.Itnotonlyhasthecapacityofautonomousdecisionandavoidingobstacles,butalsocanflexiblymoveandstronglyadaptvariableenvironment.Thecompositionoftheweldingrobotisdescribedandthedynamicmodelisestablished.Thefeasiblecontrolstrategyandcontrolalgorithmisputforward.Thesimulationexperimentsofrealworldareconducted,theresultsaresatisfying.
简介:IntheautomaticCO2arcwelding,thealterationoftheverticaldistancebetweentheweldingtorchandtheworkpiecehasastrongeffectontheweldingparameterssuchasweldingcurrentandvoltage,withtheresultthattheappearanceandqualityofweldarenotsteady.Toweakentheinfluenceofthedistancealteration,amethodisputforwardinthepaper.Themethodisthatthealternatewire-feedcontrolisusedforcompensatingtheweldingcurrent.Onthebasisoftheoreticalanalysis,astaticnumericalmodelforalternatewire-feedcontrolisestablished.Theexperimentsshowthatthemodel-basedregulationofthewirefeedratecancompensatetheweldingcurrentandensuretheappearanceofweld.Whenthealterationofverticaldistancebetweenthetorchandtheworkpieceisgreater,notonlyisthewirefeedrateregulated,buttheoutputvoltageofthepowersourceisadjustedtoensuretheappearanceandqualityofweld.