NiTi形状记忆合金激光增材制造研究进展.docx

NiTi形状记忆合金激光增材制造研究进展
摘要
NiTi形状记忆合金具有优异的形状记忆效应和超弹性行为，在航空航天、医疗器械、机械工程等领域具有广泛应用前景。激光增材制造是一种快速、高效、灵活的先进制造技术，具有制造复杂形状、逐层加工的优点。本文对于NiTi形状记忆合金激光增材制造的研究现状、发展趋势及存在的挑战进行了综述，指出了当前研究中存在不足之处，并提出了未来发展的建议。
关键词：NiTi形状记忆合金，激光增材制造，复合材料，材料特性
Introduction
NiTishapememoryalloy(SMA)isatypeofmaterialthatexhibitsshapememoryeffectandsuperelasticity.Itiswidelyusedinaviation,aerospace,medicaldevices,mechanicalengineeringandotherfields.Theshapememoryeffectreferstotheabilityofthematerialtorecoveritsoriginalshapeafterbeingdeformed.Superelasticitymeansthatthematerialundergoeslargereversibledeformationwithoutpermanentdeformationwhensubjectedtoexternalstress.Laseradditivemanufacturing(LAM)isarelativelynewtechnologythatallowsforthecreationofcomplexshapesandstructuresthroughthedepositionofmateriallayerbylayer.LAMhastheadvantageofbeingaquickandefficientmanufacturingmethod.
Inrecentyears,therehasbeengrowinginterestintheapplicationofLAMtotheproductionofNiTiSMAcomponents.ThispaperwillreviewthecurrentstateofresearchonthelaseradditivemanufacturingofNiTiSMA,discussitsdevelopmenttrendsandaddressthechallengesthatneedtobeovercome.
CurrentResearchStatus
LAMprocessesforNiTiSMAcanbeclassifiedintotwocategories:powder-basedandwire-based.Powder-basedprocessesincludepowderbedfusion(PBF)andblownpowderdeposition(BPD),whilewire-basedprocessesincludedirectedenergydeposition(DED)andwirearcadditivemanufacturing(WAAM).
Thepowderbedfusionprocessinvolvesthemeltingofmetalpowderwithalaserbeamtoformasolidcomponent.InthecaseofNiTiSMA,ithasbeenfoundthatatwo-stepheattreatmentprocessisnecessarytoobtainthedesiredshapememorybehavior.Thisprocessinvolvesahigh-temperaturesolutiontreatmentfollowedbyalow-temperatureagingtreatment.
Inblownpowderdeposition,thepowderisblownontoasubstrateandmeltedwithalasertoformasolidcomponent.Thisprocesshastheadvantageofallowingtheuseofawiderangeofmaterialsandproducingpartswithhighstrengthandlowporosity.However,itisdifficulttocontrolthesizeandshapeofthepowderparticles,whichcanleadtovariationsinmaterialproper