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20120122MATERIALSSCIENCE＆TECHNOLOGYVol．20No．1Feb．2012Nb－TiAl610031AlNb－TiAl．AlTiAlAl45．7%700℃Al700℃200MPaAlAl．Al45．7%．TiAlAlTG113．12TG113．25A1005－0299201201－0053－05StudyonsolidificationmicrostructureandmechanicalpropertiesofhighNbcontainingTiAlalloySUNHong-liangSUNCaiHUANGZe-wenZHUDe-guiKeylaboratoryofadvancedtechnologiesofmaterialsministryofeducationSouthwestJiaoTongUniversityChengdu610031AbstractTheEffectofdifferentaluminumcontentonsolidificationmicrostructureandmechanicalpropertiesofhighNbcontainingTiAlalloywasinvestigated．TheresultsindicatethatthegrainsizegraduallyincreasewithincreasingofaluminumcontentandtheperitecticreactionoccurrsinlocalregionsofTiAlalloyduringso-lidificationprocesstwhenhealuminumadditionis45．7%whichincreasegrainsizegreatly．Thecontentofa-luminumcanincreasetheroomtemperaturestrengthhightemperature700℃strengthbuttheperitecticre-actioncanreduce200MPa．TheAluminumcontenthasalittleeffectontheductility．Thecreeprupturelifehaspositivecorrelationrelationshipwiththecontentofaluminum．Tocontrolsolidificationmicrostructureandme-chanicalpropertiestheperitecticreactioninpentatomicTiAl-basedalloyshouldbeavoidedandthealuminumcontentshouldbeunder45．7%．KeywordsTiAlalloyperitecticreactionaluminumcontentmicrostructuremechanicalproperties2011－04－22．J0120602990821A0920502050907－147．1980－．TiAl、、1－2．W+Nb＞5%Al＜45%TiAlTiAl．TiAla2g．TiAl3－7．TiAl．TiAl．TiAlAl、、TiAl．AlTiAlTi－Al－Nb－W－B．1Φ20mm．1260℃150Mpa4h1．1AlloysCompositions1#Ti－42．8Al－5Nb－0．94W－0．85B2#Ti－44．4Al－5Nb－0．9W－0．9B3#Ti－45．7Al－5Nb－0．75W－1．2BΦ3．99mm×23mm．WDW31000．7×10－4/s700℃．UTSEl%．RDW5050700℃．700℃85%．FEIQuanta200ESEM20kV．22．113AlTiAlSEM．nearla-mellarα2γB2+ωγ．2．Al45．7%133．46μm113%．B2+ω．Al45．7%α2+γ1c1α2γ．1AlTiAl2、B2+ωAlloys1#2#3#Grainsize/μm52．3462．57133．46Lamellarthickness/μm1．151．221．07VolumefractionofB2+ω/%2．051．961．982．22．44．4%21#、2#700MPa700℃670MPa1%．Al、700℃．Al45．7%23#700℃200MPa．·45·20HTTSHTEL2AlTiAl2．3Al3．Al．AlAl45．7%．．3AlTiAl3TiAl－Ti－AlTi－Al8－10．Ti－Al4Al44．8～49．4at．%Ti－Al－TiAlL→βL→αAlL+#αpL+$→γp．Ti－Al．AlTiAl．TiAlTiAl－L#βAlL+#αp．ββα0001$//110β＜112－0＞$//＜111＞βαβ6110180°1112α$#α2+γα2+γ．L+#αpββ/AlL+β→αααβαα2+γ．DingX．F．TiAl5Ti－45Al－8Nb13．L+β→αβαβ→α→α2+γ120°1c2．αpα2+γ1c．4Ti-Al2Al45．7%23#700℃．Al·55·1Nb－TiAl45．7%1cα2+γ．5Ti-45Al-8NbL+β→α13TiAlW－Nb－BTi－Al－Nb－W－BTiAl．TiAlTiAl．TiAl．β14－16．、、TiAlL#βL#αL+β#αpL+α#γp．－－．TiAlL#βL#αL+#αpL+$#γpβL+β#αp．Ti－Al－5Nb－0．9W－1BAl44．4%Al．Al45．7%．Al45．7%．41．TiAlTi－Al－5Nb－0．9W－1BAl44．4%AlAl．Al45．7%700℃200Mpa．2．TiAlTi－Al－5Nb－0．9W－1BAl45．7%．1AppelFOehringMWagnerR．Noveldesignconceptsforgamma-basedtitaniumaluminidealloysJ．Inter-metallics200089－111283－1312．2DahmsM．Gammatitaniumaluminideresearchandap-plicationsinGemanyandAustriaJ．AdvancedPer-formanceMaterials199412157－182．3DuanQinqiLuanQingdongLiuJingetal．Micro-structureandmechanicalpropertiesofdirectionallyso-lidifiedHighNbcontainingTiAlalloysJ．Materials＆Design20103173499－3503．4ChenYY．YangF．KongFT．etal．MicrostructuremechanicalpropertieshotdeformationandoxidationbehaviorofTi-45Al-5．4V-3．6Nb-0．3YalloyJ．Jour-nalofAlloysandCompounds2010498195－101．5HuangZWCongT．MicrostructuralinstabilityandembrittlementbehaviourofanAl-leanhigh-Nbγ-TiAl-·65·20basedalloysubjectedtoalong-termthermalexposureinairJ．Intermetallics2010181161－172．6ZghalS．ThomasM．NakaS．etal．Phasetransforma-tionsinTiAlbasedalloysJ．ActaMaterialia20055392653－2664．7XuXJLinJPWangYLetal．Microstructureandtensilepropertiesofas-castTi-45Al-8－9Nb-WBYalloyJ．JournalofAlloysandCompounds20064141－2131－136．8McCulloughCValenciaJJLeviCGetal．PhaseequilibriaandsolidificationinTi-AlalloysJ．ActaMetall19893751321－1336．9ValenciaJJMcCulloughCLeviCGetal．Solidifica-tionMicrostructureofsupercooledTi-Alalloyscontai-ningintermetallicphasesJ．ActaMetall19893792517－2530．10JungJYParkJKChunCH．InfluenceofAlcontentoncastmicrostructureofTiAlintermetalliccom-poundsJ．Intermetallics1999791033－1041．11McCulloughCValenciaJJLeviCGetal．PeritecticsolidificationofTi-Al-Taalloysintheregionofγ-TiAlJ．Mater．Sci．Eng．1992A1562153－166．12LiuZCLinJPLiSJetal．EffectsofNbandAlonthemicrostructuresandpropertiesofhigh-Nbcontai-ningTiAlbasealloysJ．Intermetallics2002107371－380．13DingXFLinJPZhangLQetal．MicrostructuredevelopmentduringdirectionalsolidificationofTi-45Al-8NballoyJ．JournalofAlloysandCom-pounds20105061115－119．14KurodaDNiinomiMMorinagaMetal．DesignandmechanicalpropertiesofnewβtypetitaniumalloysforimplantmaterialsJ．MaterSciEng．1998A2431－2244－249．15KainumaRFujitaYMitsuiHetal．PhaseequilibriaamongαhcpβbccandγL10phasesinTi-AlbaseternaryalloyJ．Intermetallics200088855－867．16DobromyslovAVElkinVA．Martensitictransforma-tionandmetastableβ-phaseinbinarytitaniumalloyswithd-metalsof4－6periodsJ．Scriptamater．2001446905－910．526ClarkJHMacquarrieDJ．Environmentallyfriendlycat-alyticmethodsJ．ChemicalSocietyReviews1996255303－308．7CornelisALaszloP．ChemicalreactionsinorganicandinorganicconstrainedsystemsJ．ReidelNewYork1986．8VarmaRS．Clayandclay－supportedreagentsinor-ganicsynthesisJ．Tetrahedron2002581235－1255．9．J．1998545－48．10．M．2003．11．J．200727z1382－386．12．J．2008273352－357．13HayesB．L．MicrowaveSynthesisJ．CEMPubli