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1、科技導報2014。32(24)WWW.kjdb.org針壘,一........▲種新型高強高韌TC27鈦合金的高溫變形行為張業(yè)勤’,谷志飛,沙愛學’,黃利軍’,魯世強。1.北京航空材料研究院,北京1000952.內蒙古第一機械集團公司,包頭0140303.南昌航空大學材料科學與工程學院,南昌330063摘要采用Gleeble3500熱模擬機對一種新型高強高韌TC27鈦合金進行等溫恒應變速率壓縮實驗,開展TC27鈦合金的高溫變形行為研究。為制定TC27鈦合金的熱加工工藝提供依據。研究結果表明,TC2
2、7鈦合金應力應變曲線在變形溫度較低時大致呈應變軟化型;而在變形溫度較高且應變速率較低時,應力應變關系曲線基本為穩(wěn)態(tài)流動型。在應變速率為70S時,呈現(xiàn)較大幅的震蕩現(xiàn)象。TC27鈦合金的流動應力對變形溫度的敏感性在低溫變形時要顯著大于在高溫變形時的;對應變速率的敏感程度隨變形溫度的升高而降低。利用實驗數(shù)據對TC27鈦合金分別在700—850oC和850—1150℃溫度段建立了本構方程,并具有較高的精度。通過高溫變形微觀組織觀察。發(fā)現(xiàn)在變形溫度高于p轉變溫度變形時,隨變形溫度提高,或應變速率降低,動態(tài)再
3、結晶數(shù)量增加。關鍵詞高強高韌;TC27鈦合金;流動應力;本構方程;微觀組織中圈分類號TG3文獻標志碼Adoi10.39814.issn.1000—7857.2014.24.002HighTemperatureDeformationBehaviorofaHighStrengthandHighToughnessTC27TitaniumAlloyZHANGYeqin,GUZhifei,SHAAixue,HUANGLijun’,LUShiqiang1.BeijingInstituteofAeronauti
4、calMaterials,Beijing100095,China2.InnerMongoliaFirstMachineryGroupGorporation,Baotou014030,China3.SchoolofMaterialScienceandEngineering,NanchangHangkongUniversity,Nanchang330063,ChinaAbstractThehightemperaturedeformationbehaviorofTC27titaniumalloywith
5、highstrengthandhightoughnesswasstudiedthroughisothermalconstantstrain-ratecompressionexperimentsusingaGleeble3500thermo—mechanicalsimulator,whichmightDroviderefereneeforthermalprocessingofTC27titaniumalloy.Theresultsshowthatthestress—straincurvesofTC2
6、7titaniumalloyatlowtemperatureandhi【ghtemperatureroughlyCorrespondedtothesofteningtypeandsteady—state—flowtype,respectively,andsignificantshockdeclinewasobservedwhenthestrainratewas70S~.Thedependenceoftemperatureonflowstressatlowtemperaturewasmuchmore
7、significantthanthatathightemperature,andthedependenceofstrainratedecreasedwhenthetemperaturewasincreased.Basedonexperimentaldata,twohighprecisionconstitutiveequationsofTC27titaniumalloywereestablishedfortemperaturerangesof700—850oCand850—1150~C.Observ
8、ationonthemierostructureshowsthattheamountofdynamicrecrystallizedgrainsincreasedwiththeriseoftemperatureorthedecreaseofstrainratewhenthetemperaturewashigherthantransitiontemperature.Keywordshighstrengthandhightoughness;TC27titaniumalloy;flowst