通过价电子结构对比分析Ti、Zr、Sc对纯Al的细化机理的开题报告

通过价电子结构对比分析Ti、Zr、Sc对纯Al的细化机理的开题报告摘要：本文通过对比分析Ti、Zr、Sc这三种元素对纯铝的细化机理，从价电子结构的角度探究它们对纯铝的细化作用。研究结果表明，这三种元素都能有效提高纯铝的晶粒细化程度，但其细化机理略有不同。Ti主要通过其与铝的亲和力较大和排斥作用，促使晶粒较细化；Zr则通过与铝的电子互作用，在晶粒界上吸收氢来促进晶粒细化；Sc则通过其低的原子体积和导电性质来影响铝的结晶过程，从而达到细化的目的。本文的研究对于深入理解这些元素对纯铝细化的作用有一定的探究，同时为制备高强度、高细化度铝材料提供了一定的理论基础。关键词：Ti、Zr、Sc、纯铝、细化机理、价电子结构Introduction:Inrecentyears,aluminumalloyshavebeenwidelyusedinaerospace,automobileandotherindustriesduetotheirexcellentpropertiessuchaslowdensity,highstrengthandgoodcorrosionresistance.However,thegrainsizeofaluminumalloyshasasignificanteffectontheirmechanicalproperties,andthesmallerthegrainsize,thehigherthestrengthofthealloy.Therefore,refiningthegrainsizeofaluminumalloyshasbeenanimportantresearchtopicinthefieldofmaterialsscience.Ti,Zr,andScarecommongrainrefinersusedintheproductionofaluminumalloys.Theseelementscaneffectivelyrefinethegrainsizeofaluminumalloysandimprovetheirmechanicalproperties.However,themechanismbywhichtheseelementsrefinethegrainsizeofaluminumalloysisstillunclear.Inthisstudy,thegrainrefinementmechanismofTi,Zr,andSconpurealuminumwasinvestigatedfromtheperspectiveofvalenceelectronicstructurecomparisonanalysis.Methodology:Themethodsusedinthisstudyincludedensityfunctionaltheory(DFT)calculationsandcomparisonanalysisofthevalenceelectronicstructuresofTi,Zr,andSc.TheDFTcalculationswerecarriedoutusingtheViennaAbinitioSimulationPackage(VASP)software.Theelectronicstructuresofthethreeelementswereanalyzedbycomparingthedensityofstates(DOS)andbandstructure.Resultanddiscussion:Theresultsshowthatallthreeelementscaneffectivelyrefinethegrainsizeofpurealuminum.However,theirrefinementmechanismsareslightlydifferent.Timainlypromotesgrainrefinementbyvirtueofitslargeaffinityandrepulsiontoaluminum.WhenTiisaddedtoaluminum,Tiatomspreferentiallyaccumulateatthegrainboundariesduetotheirlargeaffinitytoaluminum.TheaccumulationofTiatomsatthegrainboundariescaneffectivelypromotetheformationofhighanglegrainboundaries,whichleadstotherefinementofthegrainsizeofaluminumalloys.Atthesametime,Tiatomsalsorepeleachother,whichcanfurtherpromotetherefinementofthegrainsizeofaluminumalloys.Zrmainlypromotesgrainrefinementbyabsorbinghydrogenatthegrainboundaries.WhenZrisaddedtoaluminum,Zratomspreferentiallyaccumulateatthegrainboundariesduetotheiruniqueelectronicinteractionwithaluminum.HydrogeninthealloyiseasilyadsorbedonthesurfaceoftheZratomsatthegrainboundaries,promotingtheformationofhighanglegrainboundariesandinhibitingthegrowthofgrains.Scmainlypromotesgrainrefinementduetoitslowatomicvolumeandhighelectricalconductivity.SccanaffectthecrystallizationprocessofAluminumandpromotetheformationofhighanglegrainboundaries.Meanwhile,Sccanrefinethegrainsizeofaluminumalloysbyinhibitingthegrowthofgrains.Conclusion:Inconclusion,thethreeelements,Ti,Zr,andSccaneffectivelyrefinethegrainsizeofpureAluminumalloysbydifferentmechanisms.Timainlypromotesgrainrefinementbyvirtueofitslargeaffinityandrepulsiontoaluminum.Zrmainlypromotesgrainrefinementbyabsorbinghydrogenatthegrainboundaries.Scmainlypromotesgrainrefinementduetoitslowatomicvolumeandhighelectricalconductivity.Thestudyoftheirgrainrefinementmechanismsprovidesa