简介：TheeffectofdeformationconditionsondynamicrecrystallizationbehaviorofNb,V,Timicroalloyedhigh-strengthstructuralsteelwasinvestigatedviahigh-temperaturesinglepassreductiontestsonaMMS-300thermomechanicalsimulator,withmathematicalmodelsestablishedforflowstressduringhotdeformation.Theresultsshowthatthedeformationresistancedecreaseswiththeincreaseoftemperatureandisinpowerfunctionrelationshipwiththetemperature.Meanwhile,itincreaseswiththeincreaseofstrainrateandisinlog-logrelationshipwiththestrainrate.Thedynamicrecrystallizationactivationenergyoftestedsteelwasdeterminedtobeabout329.55kJ/mol,295.31kJ/molatpeakandsteadystates.Thepredictionmodelsdevelopedforflowstressindicatedthattheyareingoodagreementwithexperimentalresults.

简介：Thehot-deformationbehaviorofFe-Mn-Ctwinninginducedplasticity(TWIP)steelwasinvestigatedbyconductinghotcompressiontestswithinarecommendedhotrollingtemperaturerangeatvariousstrainrates.Flowresistancecurvesduringhot-deformationwereobtained,andstrainratesensitivitiesandactivationenergiesforplasticdeformationwerecalculatedusingthepowerlaw.ItisfoundthattheadditionofAlandSiclearlyincreasesthepeakstressesforthepresentalloys,especiallyat950℃.ButMnhasaminoreffectonthestress-straincurvesandactivationenergywhenitscontentvariesfrom15mass%to22mass%forthepresentalloys.

简介：InordertosuppressthesurfacecrackinginducedbyCuduringreheatingandhotrollingprocess,Cuenrichmentanditsmigrationatthesteel-scaleinterfacewasinvestigatedduringheatingofsteelcastattemperaturesbetween1000℃and1200℃inN2-O2andN7-H2Oatmospheres.ForoxidationofCucontainingsteel,CuenrichedphasewasformedbythepreferentialoxidationofFeandtheenrichmentandmigrationbehaviorofCudependsontheoxidationtemperature,steelchemistryandatmospherecondition.NiinsteelinducedtheformationofsolidCuandNienrichedphaseatsteel/scaleinterfaceandinscalelayerandtheformationofunevensteel/scaleinterface,whichsuppressestheCuenrichmentbecauseofextrusionofCuenrichedregionbeforetheformationofliquidphase.Ontheotherhand,SnadditionpromotestheliquidCuformationatsteel/scaleinterfaceandpenetrationintograinboundaryofCuenrichedphasebydecreasingsolidustemperatureandsolubilitylimit.Inaddition,foroxidationat1200℃,thebehaviorofCuatandaroundthesteel-scaleinterfacewasfounddependenttoalargeextentonmorphologyoftheoxidescaleformedduringoxidation.Attheearlystageofoxidation,Cu-richphaseformedandaccumulatedatthesteelscaleinterfaceunderbothO2-N2andH2O-N2atmospheres.Astheoxidationproceeded,however,Cuenrichmentatanditsmigrationfromthesteel-scaleinterfacewerevastlydifferentfordifferentoxidizingatmospheres.InthecaseofO2-N2oxidation,anoxidelayerformedinitiallyatthesteelsurface,butsoonafteragapwasdevelopedatthesteel-scaleinterfaceandgrewinitssize,whichpracticallyseparatedthescalefromthesteelsubstrate.Thescalelayerformedunderthisconditionwasporous.TheCu-richphaseinitiallyformedattheinterfacewasfoundmigratingtothescalelayer,leavingnoCu-richphaseattheinterface.InthecaseofH2O-N2oxidation,however,thescalelayerformedwasdenseandtightlyattachedtothesteelsurface,andtheCurich-phasecontinuedto

简介：ItisfundamentallyimportanttounderstandtheinfluenceofstrainonthedensityofdeformationtwinsinTWIPsteelbecausetwinningisitsdominantdeformationmechanism.ThedeformationbehaviorofaFe-30Mn-4Si-3Al-0.097CsteelhasbeeninvestigatedbyX-raydiffraction(XRD),electronbackscatterdiffraction(EBSD)andtransmissionelectronmicroscopy(TEM)techniques.Samplewithanaveragegrainsizeof10μmwasdeformedincold-rollingwithareductionof10%,20%,30%,40%,50%,60%and70%,respectively.Themechanicalpropertiesofthecold-rolledsampleswerefurtherinvestigatedbytensiletests.Theyieldstrength(σy)andultimate-tensile-strength(σUTS)oftheas-preparedsampleis480MPaand850MPa,respectively.However,undercoldrollingdeformation,thetensilestrengthobviouslyincreaseswithanincreaseinrollingreduction.Thesamplewitharollingreductionof10%exhibitsσyof610MPaandσUTSof-1000MPa.Theyieldstrengthandtensilestrengtharefurtherenhancedupto1320MPaand1378MPaforthespecimenwitharollingreductionof70%,regardlessofthepoorductilityof6.7%.ThedeformationmicrostructureswerestudiedbyEBSDandTEMobservations.Itisfoundthat,withincreasingrollingreduction,theaveragedistancebetweendeformationtwinsdecreasesgraduallywhilethedensityofdeformationtwins(thelengthoftwinboundaryinunitarea)exhibitamaximumvalueat40%cold-rolling+tension.Carefullystatisticsanalysisrevealsgrainorientationiscloselyrelatedtothedeformationtwinsandtheunderlyingmechanismgoverningthetwinningisdiscussed.

简介：ＥｆｅｃｔｏｆＲａｒｅＥａｒｔｈｓｏｎＴｅｎｓｉｌｅＢｅｈａｖｉｏｒｏｆＨｏｔＲｏｌｅｒＳｔｅｌ６０ＣｒＭｎＭｏａｎｄＥｓｔｉｍａｔｉｏｎｏｆＲｏｌ′ｓＦａｔｉｇｕｅＬｉｆｅＹａｎｇＱｉｎｇｘｉａｎｇ（杨庆祥），ＺｈｕＧｕａｎｇｒｏｎｇ（朱广荣），...

简介：ThemorphologyandcorrosionbehaviorofNi/Al2O3compositecoatingspreparedusingdouble-pulsedelectrodepositingtechniqueafteroxidizedunder800℃NaCldepositinairenvironmentwereanalyzedbyscanningelectricalmicroscope(SEM),X-raydiffraction(XRD)andenergydispersivespectrum(EDS).TheresultsshowedthatthecorrosionofallcompositecoatingswasacceleratedunderNaCldeposits,andthecorrosionproductswereratherporouswithpooradherencetothematrix.Al2O3particlesinthecoatingscanrefinethegrainsizeandimprovethehightemperaturecorrosionresistanceofthecoatings.Withinthetestscope,themoreAl2O3particlesinthecoatings,thelowercorrosionratescouldbeobtained,andthecorrosionmechanismwasalsodiscussed.

简介：Theeffectsofthesubstratetemperatureonthedepositionandmicrostructureofthe304stainlesssteel(SS)coldgasdynamicspraying(CGDS)coatingswereinvestigated.Itwasfoundthatthehighersubstratetemperaturecouldincreasethedepositionrateofthe304SSparticles,eventheoxidefilmsexistedattheinterface.Therewasacriticaloxidefilmwithathicknessof3-4μmwhichcouldbedestroyedbytheimpactedparticles.Themicro-hardnessandmicrostructureofthe304SScoatingsunderdifferentsubstratepreheatingtemperatureswerealmostthesame.

简介：试图为高温度的熔融的盐反应堆的安装和电极的建设开发材料，在750和950湩爠晥湩浥湥?瑳敲杮桴湥湩?猠汯摩猠汯瑵潩?瑳敲杮桴湥湩?眠牯?慨摲湥湩?愠摮瀠敲楣楰慴楴湯猠牴湥瑧敨楮杮的Ni-11Fe-10Cu的高温度的氧化行为上的艾尔和Y的效果

简介：TheLa-CosubstitutedSr_（1–x）La_xFe_（12–x）Co_xO_（19）（x=0–0.5）ferriteswithappropriateBi_2O_3additivewerepreparedbyconventionalsinteringmethodandmicrowavesinteringmethodatlowsinteringtemperaturescompatiblewithLTCC（lowtemperatureco-firedceramics）systems,andtheirsinteringbehaviorwaschieflyinvestigated,includingthecrystalstructure,saturationmagnetizationMs,magneticanisotropyfieldHa,intrinsiccoercivityHci,andCurietemperatureTC.ExperimentresultsclearlyshowedthatthepureM-typecrystalphasewassuccessfullyobtainedwhentheLa-Cosubstitutionamountxdidnotexceed0.3.However,thesingleM-typephasestructuretransformedtomultiphasestructurewithfurtherincreasedx,wheretheM-typephasecoexistedwiththenon-magneticphasesuchasα-Fe_2O_3phase,La_2O_3phase,andLaCoO_3phase.AppropriateLa-CosubstitutionimprovedtheMs（〉62emu/g）,Ha（〉1400kA/m）,andHci（〉320kA/m）fortheferriteswithxvaryingfrom0.1to0.3,buttheTCdecreasedwithincreasingsubstitutionamount.Moreover,themicrowavesinteredferritescouldprovidelargerHciandsimilarMscomparedwiththeconventionalsinteredferrites.

简介：

简介：Inthisstudy,threekindsofdual-phase(DP)steelswereusedtoinvestigatetheinfluenceofsiliconcontentandintereriticalannealingtemperatureontheirmicrostructures,mechanicalproperties,andwork-hardeningbehaviors.Byaddingsiliconandmatchingthecriticalannealingtemperature,anewDPsteel(1.0Siandintercriticallyannealedat790℃)thatexhibitsanexcellentcombinationofultrahighstrengthandadequateductilitywasobtained.Variationsinthestrength,elongation,andfracturemechanismofthespecimenswithrespecttodifferentintercriticalannealingtemperatureswerecorrelatedtomicrostructuralfeatures.Withanincreaseinthesiliconcontent,thereisnosignificantchangeinthemartensiticbandstructureorferritemorphology.Atthesameannealingtemperature,theyieldstrengthandyieldstrengthratioofthespecimensdecreased,butatdifferentannealingtemperatures,thetensilestrengthwasreduced.TheHollomonanalysisresultsindicatethattheworkhardeningbehaviorobeysatwo-stagework-hardeningmechanism.Withanincreasingintercriticalannealingtemperature,the"transitionstrain"shiftstotheleft,andwithanincreasingsiliconcontent,the"transitionstrain"shiftstotheright.Thesurfaceexhibitsductilefracturescharacterizedbyahighdensityofmicrovoiddimples.Withanincreaseinthesiliconcontent,theaveragedimplesizeonthefracturesurfacedecreasesandtheplasticityofthematerialincreases.

简介：

简介：NominalcompositionofCa1-xZnxTiO3:0.002Pr3+(x=0.000～0.200)phosphorswerepreparedbyconventionalsolidreactionroute.XRDandPLmeasurementswereusedtoinvestigatethesolid-solutionstructureandluminescencepropertiesofZn-dopedCa1-xZnxTiO3:0.002Pr3+phosphors.Theeffectofsolid-solutionstructureformedbysubstitutionbetweenCa2+andZn2+ionsontheluminescentpropertieswasanalyzed.Theresultsrevealthat,withtheincreaseofZnsubstitutioncontentbelow0.010,latticeparametersandtheintensityofexcitationpeakatboth260and330nmaswellasthecorresponding610nmemissionintensityaremonotonouslydecreasedquicklyinasimilartendency.Also,theevolutionofluminescenceintensityandcrystalcellparametersagainstZndopingconcentrationareingoodagreement.AboveresultsarecloselyrelatedwiththestructurechangewithinCa1-xZnxTiO3:0.002Pr3+solid-solutionphaseformedbytheZnionssubstitutionfortheCasites.Presentstudyrevealsthatthesolid-solutionstructureformedbysubstitutionbetweenCa2+andZn2+ionshassignificanteffectontheluminescencepropertiesofsinglephaseCa1-xZnxTiO3:0.002Pr3+phosphors.