学科分类
/ 3
49 个结果
  • 简介:1IntroductionTheelectrolyticmanganesedioxide(EMD)iswidelyusedinzincmanganeseandlithiummanganesecels.Itwasestimatedthatthe...

  • 标签: Ti MN COMPOSITE ANODE Electrolytic MANGANESE
  • 简介:Permanentmagneticmaterialscapableofoperatingathightemperatureupto500°Chavewidepotentialapplicationsinfieldssuchasaeronautics,space,andelectroniccars.SmCoalloysarecandidatesforhightemperatureapplications,sincetheyhavelargemagnetocrystallineanisotropyfield(6–30T),highCurietemperature(720–920°C),andlargeenergyproduct([200kJám-3)atroomtemperature.However,thehighestservicetemperatureofcommercial2:17typeSmComagnetsisonly300°C,andmanyeffortshavebeendevotedtodevelopnovelhightemperaturepermanentmagnets.ThisreviewfocusesonthedevelopmentofthreekindsofSmCobasedmagnets:2:17typeSmComagnets,nanocrystallineSmComagnets,andnanocompositeSmComagnets.Theoxidationprotection,includingalloyingandsurfacemodification,ofhightemperaturepermanentmagnetsisdiscussedaswell.

  • 标签: 高温永磁材料 高温永磁体 钐钴合金 磁晶各向异性场 最高使用温度 纳米复合材料
  • 简介:IntroductionIMI829titaniumaloyisakindofhightemperaturenearαaloy.Itsservicetemperatureisupto580℃.IthasbeenusedinRB211525E4en...

  • 标签: YTTRIUM ALLOY MICROSTRUCTURE PROPERTY
  • 简介:Intheacceleratordrivensub-criticalsystem(ADS)cooledbyliquidPbBialloy,theausteniticstainlesssteel316Lisoneofthecandidatesofstructuralmaterials.However,thecorrosionandwearbehaviorof316Lsteelinthehigh-velocitystreamofliquidPbBiisthemostessentialissue,whichisurgenttobepaidcloseattention.Inordertoacquirethemorphologyandmechanicalpropertiesof316Lsteelintheconditionsofdifferentrelativeflowingvelocity(RFV),respectively2.62m/s,3.69m/s,4.77m/s,theexperimentwascarriedoutindynamicliquidPbBiat550℃,uptoabout1500h.Accordingtotheresults,thesurfaceof316LhasbeencorrodedbadlyandtheelementsofNi,Cr,etc.werefoundtodissolvealot.WiththeincreaseoftheRFV,thefeatureof316Lsurfacechangedfromthesurfacewithmuchdeeperpitsandlooserstructurestotherelativeplanarone,andthethicknessoftheouteroxidelayerdecreasedgraduallywhilethatoftheinneroxidelayerdiminishedalittle,andthemicrohardnessoftheoutermostsubstratealsodeclinedincreasingly,inaddition,thedomainofthepartialsubstratewithitsmicrohardnessbeingaltereddeepenedfurther.Theseexperimentaldatawouldoffertheoreticalbasisandpracticalvaluestostudycorrosionconditionof316LsteelinliquidPbBiwithhigh-velocity.

  • 标签: 奥氏体不锈钢 力学性能 形态学 液态 316l 性能评价
  • 简介:因为它的吸引人的表演,超导的nanowire单身者光子察觉者(SNSPD)在极端紫、可见、在红外线附近的波长引起许多注意,并且它能在量信息技术是普遍的。然而,怎么增加罐头戏剧性地增加SNSPD的量效率的吸收仍然是一个顶研究问题。在这研究,洞综合的SNSPD的光吸收比上的事件媒介和洞材料的效果系统地用有限元素的方法被调查。模拟结果为光子表明那极化的平行到nanowire取向尽管nanowire的最大的吸收比对洞材料感觉迟钝,事件媒介的折射索引什么时候减少,确实增加。为垂直地极化的光子,事件媒介和洞材料起重要作用,并且吸收比曲线作为洞材料增加的折射索引接近平行案例。把结果基于这些,有能为平行、垂直的光子提高吸收比的前面照明结构的二洞综合的SNSPD被建议。最后,与高吸收比认识到极化无关的SNSPD的一个图案被介绍。

  • 标签: 单光子探测器 偏振无关 纳米线 检测效率 超导 光吸收率
  • 简介:Na离子电池由于他们的低费用和自然许多Na资源为大规模精力存储系统被认为一种有希望的选择到Li离子电池。大努力全球正在做为Na离子电池开发高效的电极材料,它为Na离子电池是批评的。这评论基于Na存储机制为Na离子电池提供阳极材料的全面概述:基于插入的材料,基于合金的材料,基于变换的材料和器官的composites。并且我们总结那些阳极材料的Na存储机制并且讨论他们的失败机制。而且,与那些阳极联系的问题和挑战被指出,并且可行策略为设计高效的阳极材料被建议。根据研究的当前的状态,尽管实质的进步被获得了,为为Na离子电池的合适的阳极材料的搜索仍然是挑战性的。不过,我们相信高效的Na离子电池在不久的将来将为在大规模精力存储系统的实际应用程序是有希望的。

  • 标签: 阳极材料 电池开发 NA 离子 存储机制 存储系统
  • 简介:Crackopeningdisplacement(COD)wasappliedtocharacterizethefractureinitiationofthetoughhighdensitypolyethylene.Normalsinglesidenotchedthree-pointbendspecimensandsilicarubberreplicatechniqueswereusedtostudythecharacteristicCODofhigh-densitypolyethylenepipeanditsbutt-fusionjointsincludingtheweldfusionzoneandheataffectedzoneatdifferenttemperaturefrom-78℃to20℃.TestingresultsshowthatthecharacteristicCODappearstodependonthestructuralfeaturesthataredeterminedbyweldingprocessandthetestingtemperature.Asthetemperatureislowered,thecharacteristicCODofallzonesstudieddecreases.Becausetheweldingprocesssignificantlychangessomestructuralfeatureofthematerial,characteristicCODoftheweldfusionzoneisthesmallestoneamongthoseofthethreezones.TheresultscanbeusedfortheengineeringdesignandfailureanalysisofHDPEpipe.

  • 标签: 熔焊 高密度聚乙烯管 断裂 裂纹张开位移 COD HDPE
  • 简介:Theeffectofsolidificationrateonthemicrostructuredevelopmentofnickel-basedsuperalloyunderthetemperaturegradientof500K·cm-1wasstudied.Theresultsshowthat,withtheincreaseofdirectionalsolidificationratefrom50to800μm·s-1,boththeprimaryandthesecondarydendritearmspacingsofthealloydecreasegradually,andthedendritemorphologiestransformfromcoarsedendritetosuperfinedendrite.Thesizesofallprecipitatesinthesuperalloydecreasegradually.Themorphologyof...

  • 标签:
  • 简介:InhighspeedMAGweldingprocess,someweldformationdefectsmaybeencountered.Togetgoodweldquality,thecriticalweldingspeedbeyondwhichhumpingorundercuttingweldbeadcanoccurmustbeknownfordifferentconditions.Inthisresearch,highspeedMAGweldingtestswerecarriedouttocheckouttheeffectsofdifferentfactorsonthecriticalweldingspeed.ThroughobservingtheweldbeadprofilesandthemacrographsofthetransversesectionsofMAGwelds,theoccurrencetendencyofhumpingweldwasanalyzed,andthevaluesofcriticalweldingspeedweredeterminedunderdifferentlevelsofweldingcurrentorvoltage,andtheeffectofshieldinggascompositionsonthecriticalweldingspeedwasalsoinvestigated.

  • 标签: 高速MAG焊接 临界焊接速度 焊接工艺 焊接速度
  • 简介:Al-Mn阶段的形态学上的高磁场的效果被调查。这被发现向性和艾尔6Mn猛抛阶段在高磁场下面变得常规。越强壮高磁场,越多常规艾尔6Mn猛抛阶段。艾尔6Mn猛抛阶段能在不同温度通过Al-Mn合金的熄灭的微观结构的观察在高磁场下面产生面向的排列和聚集。同时,艾尔6Mn与高磁场的增加的功能时间一起连续地分阶段执行增加。X光检查衍射也显示那艾尔6Mn阶段在高磁场下面产生明显的向性。聚集的进程和艾尔6Mn猛抛在在取向以后的高磁场的函数下面的阶段被分析并且讨论。

  • 标签: 高磁场 凝固组织 Al 合金 MN X射线衍射分析
  • 简介:MechanicalpropertiesofSMAW(shieldedmetalarcwelding)weldmetal(yieldstrengthhigherthan900MPa)withsystematicadditionsofcopper(upto1.48wt%)weretested.Themicrostructureandprecipitatesindifferentregionswereanalyzedbyopticalmicroscopeandtransmissionelectronmicroscope.Theresultsindicatethatcopperimprovesthelowtemperaturetoughnessofweldmetalwhenthecoppercontentislowandreachesthepeakvalue48J(at-50℃)with0.2wt%copperadditions.Whenthecontentishighthecopperprecipitatesasε-Cuphaseinthereheatzoneofmiddlebeads.Theseprecipitatesimprovethestrengthoftheweldmetalevidently(yieldstrengthupto975MPa)withoutobviouseffectonthelowtemperaturetoughness.Thecopperwithin1.1wt%contentcanimprovethestrengthwithouttoughnessloss.

  • 标签: 金属保护电弧焊 强度 焊缝金属 力学性能
  • 简介:Thethermaldiffusioncoefficient,thermalconductivity,andthermalexpansioncoefficientofCuCralloypreparedbyinfiltrationweremeasuredbythermalconstanttesteranddilatometerbeforeandafterhighpressureheattreatment,atthesametime,theeffectofhighpressuretreatmentonthethermalphysicalpropertiesofCuCralloywasdiscussedbytheanalysisofitsmicrostructure.TheexperimentalresultsshowthathighpressureheattreatmentcanincreasethethermaldiffusioncoefficientandthermalconductivityofCuCralloy,butitchangesslightlyinthepressurerangeof1–6GPa.Asforthermalexpansioncoefficient,whenthetemperatureishigherthan130°C,itisobviouslyhigherthanthatofthealloywithouthighpressuretreatmentafter1GPapressuretreatment,andthehigherthetemperatureis,thelargertheirdifferencesare.

  • 标签: 高压处理 铜铬合金 热物理性能 组织演变 热扩散系数 热膨胀系数
  • 简介:Fromtheviewpointofweldingmechanics,twonewweldingmethods-weldingwithtrailingpeeningandweldingwithtrailingimpactiverollingwereintroduced.Foraluminumalloythin-shellstructureswithhighstrength,weldingwillleadtohotcracking,poorjointanddistortion.Inordertosolvethem,trailingimpactivedevicewasusedbehindweldingtorchtoimpactthedifferentpositionsofweldedjoints,thusrealizingtheweldingwithfree-hotcracking,lowdistortionandjointstrengthening.Byuseofimpactiverollingwheelsinsteadofpeeningheads,theoutlookofweldedspecimencanbeimprovedandstressconcentrationatweldtoescanbereduced.Equipmentofthistechnologyissimpleandportable.Itcanusedtoweldsheets,longitudinalandring-likebeamsoftube-likestructures,aswellasthethin-shellstructureswithclosedweldssuchasflangesandhatches.Sothetechnologyhasthewideapplicationforegroundinthefieldsofaviationandaerospace.

  • 标签: 铝合金 薄板 焊接 航空 变形
  • 简介:OnthebasisOftheYoung-LaplaceEquationthatdescribesthepressuredifferencebetweeneachsideofacurvedliquidsurface,astaticequilibriummodelisestablishedtodescribethesurfaceshapeoftheweldbead.Thegeo-metricalmodelforthemoltenpoolisincluded,whichisessentialtoexplaintheundercutphenomenonduringhighspeedbead-on-platewelding.Theresultsgotfromaniterationalgorithmshowthatitistheforcebalanceontheliquidmixtureofthedepositedmetalandthedepositedmetalandthemoltenbasemetalandthemoltenbasemetalthatcausestheundercut.Somefactorsandtheireffectsarealsoana-lyzed.

  • 标签: STATIC EQUILIBRIUM Young-Laplace EQUATION SURFACE tension