简介:用x射线衍射、光学显微镜、扫描电镜和能谱等分析Al-10Ce中间合金的相组成和微观形貌,研究Al-10Ce中间合金对α-铝的变质处理效果及对α-铝的长效性变质和重熔稳定性变质,并与钠盐变质进行了对比。结果表明:Al-10Ce中间合金用量对变质效果的影响很大,Al-10Ce中间合金用量为0.30%左右时达到最佳变质效果,用量少变质效果差,用量过多则形成过变质。用Al-10Ce中间合金对α-铝进行变质,可取得极好的变质效果,变质持续时间比钠盐变质剂更长久且具有更好的重熔稳定性。
简介:Inpursuingexcellentsupercapacitorelectrodes,wedesignedaseriesofM0S2/C0S2compositesconsistingofflower-likedMoS2andoctahedron-shapedCoS2throughafacileone-stephydrothermalmethodandinvestigatedtheelectrochemicalperformanceofthesampleswithvarioushydrothermaltime.Duetothecouplingoftwometalspeciesandabigamountofwell-developedCoS2andMoS2,theresultsindicatedthattheMoS2/CoS2compositeselectrodesexhibitedthebestelectrochemicalperfor-mancewithalargespecificcapacitanceof490F/gat2mV/sor400F/gat10A/gamongallsamplesasthehydrothermaltimereached48h(MCS48).Furthermore,theretentionofMCS48is93.1%after10000cyclesat10A/g,whichmanifeststheexcellentcyclingstability.TheoutstandingelectrochemicalperformanceofMCS48indicatesthatitcouldbeaverypromisingandnovelenergystoragematerialforsupercapacitorsinthefuture.
简介:Inthepaper,theauthorsanalysetherela-tionshipbetweentheelectricalconductivityσofZrO2andthecontentofdopedstabilizingagentbythePositronAnnihilationTechnique,andexplainthechangetendencyofσwiththecontentofstabilizingagent.Theresearchshowsthat"numberofeffectivevacancy"inmaterialisadecisivefactorcausingchangeofσ.
简介:(Ni0.81Fe0.19)0.66Cr0.34hasahighresistivityandacrystalstructureclosetothatofNi0.81Fe0.19.TheelectricalandX-raydiffractionmeasurementsprovethatathinNiFeCrseedlayerinducesawell(111)-orientedNi0.81Fe0.19film.Post-annealingtreatmentimprovesthemagneticpropertiesof(Ni0.81Fe0.19)0.66Cr0.34(45A)/Ni0.81Fe0.19(150A)/Ta(55A)thinfilmpreparedunderadepositionfield,whereastheinter-diffu-sionofNiFe/Tadeterioratesthemagnetoresistancepropertiesofthefilm.
简介:ThehomogeneousplasticflowoffullyamorphousandpartiallycrystallizedZr41.2Ti13.8Cu12.5Ni10Be22.5bulkmetallicglass(Vitl)hasbeeninvestigatedbycompressiontestsathightemperaturesinsupercooledliquidregion.Experimentalresultsshowthatatsufficientlylowstrainrates,thesupercooledliquidofthefullyamorphousalloyrevealsNewtonianflowwithalinearrelationshipbetweentheflowstressandstrainrate.Asthestrainrateisincreased,atransitionfromlinearNewtoniantononlinearflowisdetected,whichcanbeexplainedbythetransitionstatetheory.Overtheentirestrainrateintervalinvestigated,however,onlynonlinearflowispresentinthepartiallycrystallizedalloy,andtheflowstressforeachstrainrateismuchhigher.Itisfoundthatthestrainrate-stressrelationshipforthepartiallycrystallizedalloyatthegiventemperatureof646Kalsoobeysthesinhlawderivedfromthetransitionstatetheory,similartothatoftheinitialhomogeneousamorphousalloy.Thus,itisproposedthattheflowbehaviorofthenanocrystalline/amorphouscompositeat646Kismainlycontrolledbytheviscousflowoftheremainingsupercooledliquid.
简介:Nd_2Zr_2O_7isbeingexploredasanalternatethermalbarriercoating(TBC)materialforoperatingabove1300°C,andgreatefforthasbeenmadetoenlargeitsthermalexpansioncoefficient(TEC)andimproveitstoughness.Inthisstudy,Sc_2O_3wasdopedtoNd_2Zr_2O_7.Thephasestructure,TECsandtoughnessof((Nd_(1-x)Scx))_2Zr_2_O7(x=0,0.025,0.05,0.075,0.1)compoundswereinvestigated.((Nd_(1-x)Scx))_2Zr_2_O7(x=0,0.025,0.05,0.075)exhibitedpyrochlorestructure,while((Nd_(0.9)Sc_(0.1)))_2Zr_2O_7consistedofpyrochloreandfluoritephases.WiththeincreaseoftheSc_2O_3content,theorderingdegreeofthepyrochloreinthecompoundsdecreased.In((Nd_(1-x)Scx))_2Zr_2O_7series,((Nd_(0.925)Sc_(0.075)))_2Zr_2O_7exhibitedthelargestTEC,whilethetoughnessofthecompoundsincreasedwithincreasingtheSc_2O_3content.Therelatedmechanismswerediscussedbasedonthecrystalstructureanalysis.ConsideringtheTECandtoughness,10mol%Sc_2O_3wassuggestedastheoptimaldopingcontentforNd_2Zr_2O_7ceramic.