简介:FenanowirearraywithstrongshapeanisotropywasemployedasthesoftphaseinNd-Fe-Bbasednanocomposites.TheeffectsoftheFenanowiredistributiononmagneticpropertiesofthenanocompositeswereinvestigatedbymicromagneticsimulation.TheresultsindicatethattheshapeanisotropyofFewiresaddedinthesamedirectionastheuniaxialmagnetocrystallineanisotropyofthehardphasecannotincreasethecoercivityofthenanocomposite.Whenthenanowiresaredistributedperpendiculartotheeasyaxisofthehardphase,theshapeanisotropyofsoftphasecanretardthemomentsfromrotatingtothefullreverseddirection,leadingtoenhancedcoercivity.Inaddition,withincreasingthenanowirediameter,thecoercivityofthenanocompositedecreases,butthedipolarinteractionshowsdifferentrolesinmagneticreversalofnanocompositefordifferentdistributionsofnanowires.ThecurrentresultssuggestthatthecoercivityoftheNd2Fe14B/α-Fenanocompositecanbeenhancedbyintroducingthesoftmagneticnanowirearraywiththediameterlessthantheexchangelengthandwiththelongaxisalongthedirectionotherthantheeasyaxisofhardphase.
简介:PositronannihilationbehaviorshavebeenstudiedinthesinglephaseNd2Fe14BmagnetandthenanocompositeNd2Fe14B/α-Femagnet,preparedbymeltspinning.Theresultsshowedthatthenumberofvacancy-clusteratgrainboundariesincreaseswithincreasingannealingtemperatureforthebothtypesofmagnets.Theincreaseofthiskindofdefectcanimprovethecoercivityof
简介:1.IntroductionSofarthemicrostructureandcoercivityofSm(Co,Cu,Fe,Zr)7.4alloyhavebeenstudiedindetailbyvariousauthors.TheeffectofZr-richlaminarphasestructureonthehighcoecivityofalloyismoreattractive.Thechangesofmagnetic
简介:ThebasestructureofinsituTiCP/Fecompositesfabricatedunderindustrialconditionwaschangedbydifferentheattreatments.Erosiveweartestswerecarriedoutandtheresultswerecomparedwiththatofwear-resistantwhitecastiron.TheresultssuggestthatthewearresistanceoftheinsituTiCp/Fecompositeishigherthanthatofwear-resistantwhitecastironunderthesanderosivewearcondition.Thewearmechanismofthewear-resistantwhitecastironwasacycleprocessthatbasesurfacewaswornandcarbideswereexposed,thencarbideswasbrokenandwearpitsappeared.WhilethewearmechanismofinsituTiCp/FecompositewasacycleprocessthatbasesurfacewaswornandTiCgrainswereexposedanddropped.ThewearresistanceofinsituTiCp/Fecompositewaslowerthanthatofwear-resistantwhitecastironundertheslurryerosivewearcondition.Undersuchcircumstance,thematerialwasnotonlyundergoneerosivewearbutalsoelectrochemistryerosionduetothecontactwithwaterinthemedium.Thewearbehaviourscanbeacombinationoftwokindsofwearandthesanderosivewearisworsethanslurryerosivewear.
简介:NitridingisemployedforthehardFeelectrodepositiontoproduceahard-facingandantiwearcoating.Itonlytakes1hforthehardFecoating,whichismuchshorterthannitridingtheFeandsteel.Theresultsshowedthatthenitridingcanincreasethemicrohardness,wearresistanceofthecoating,aswellasthebondingstrengthofthecoatingwiththesubstrate.Additionallyitcaneliminatethebrittleness,turntheinternalstressofthecoatingfromtensiontocompression.ThewearresistanceofthenitridedFecoatingis4.6timesashighasthatofCrcoating.ItissimpleandeconomictocombinehardFeelectroplatingandnitriding,whichisagoodtechnologyofthetribologicalsurfacemodification.
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简介:1.IntroductionLightrareearthadditioncanremarkablyenhancetheservicelifeofFe-Cr-Alalloyforelectricalheatingelement,butitscontentinthealloymustbecontrolledbelowthelevelof0.1wt-%.Whenthecontentexceedsthat,theperformance
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简介:Basedonthedifferenceofhydroxygroupconfigurationondifferentplanesofα-Fe2O3nanoparticles,usingthespecialadsorptionandcoordinationofphosphateonthe(001)planeofα-Fe2O3,well-crystallizedandwelldispersedα-Fe2O3nanodiskswithdiameterof150–200nmandthicknessof40–80nmweresynthesizedviaahydrothermalmethod.Themagneticpropertiesofsynthesizednanodiskswereinvestigated.Itwasfoundthatthenanodiskspossessedasaturationmagnetization(Ms)of0.38emu/g,aremanentmagnetization(Mr)of0.031emu/gandacoercivityof452.91Oeatroomtemperature.TheMrandcoercivityofsynthesizedα-Fe2O3nanodisksarehigherandtheMsislowerthanthoseofotherpreviouslyreportedα-Fe2O3nanostructures.
简介:Fe-Ni-Almixturesashot-pressingsinteringadditivetoTitaniumdiboride(TiB2)werestudied.ItisfoundthatliquidalloyformedunderhightemperaturehardlyhaseffectsonthedensificationbehaviorsofTiB2-independent.Fe-Ni-AladditivejustworksasfillerbetweenTiB2particlesanddoesnotchangetheTiB2-independentsinteringbehaviors.PressingmodehasagreateffectontheliquidflowingbetweenTiB2particles.Multiple-stepspressingmodewillgivemoretimeandspacefortheliquidflowingandimprovetherelativedensityofTiB2-Fe-Ni-Alcermet.