پديد آورنده :
عطاپور، مسعود
عنوان :
تاثير ريز ساختار و مورفولوژي فازي بر رفتار خوردگي مقاطع جوش آلياژ Ti-6Al-4V ايجاد شده با فرايندهاي جوشكاري قوسي تنگستن-گاز و اصطكاكي اغتشاشي
مقطع تحصيلي :
كارشناسي ارشد
محل تحصيل :
اصفهان: دانشگاه صنعتي اصفهان، دانشكده مواد
صفحه شمار :
ده،122ص.: مصور،جدول،نمودار
يادداشت :
ص.ع.به فارسي و انگليسي
استاد راهنما :
محمد حسين فتحي، مرتضي شمعانيان
تاريخ نمايه سازي :
21/6/90
استاد داور :
محسن صارمي، فرشيد كاشاني بزرگ، محمدعلي گلعذار
كد ايرانداك :
ID385 دكتري
چكيده فارسي :
به فارسي و انگليسي: قابل رويت در نسخه ديجيتالي
چكيده انگليسي :
Microstructure and phase morphology effects on the mechanism andcorrosion behavior of Ti 6Al 4V alloy after Gas Tungsten Arc Welding and Friction Stir Welding procedures Masoud Atapour E mail atapoor@ma iut ac ir Date of Submission March 24 2011 Department of Materials Engineering Isfahan University of Technology Isfahan 84156 83111 IranSupervisor M H Fathi Fathi@cc iut ac ir and M Shamanian shamanian@cc iut ac ir Advisor G S Frankel J C Williams J Lippold and A Pilchak Ohio State University Department Graduate Program Coordinator Masoud PanjehpourAbstractThe corrosion behavior of the investment cast Ti 6Al 4V alloy in 5 HCl solution wasinvestigated after gas tungsten arc welding GTAW or the friction stir welding For finding thecorrosion mechanisms and evaluation of the microstructures correlation and corrosion behaviorof Ti 6Al 4V alloy the corrosion behavior of four different microstructures of Ti 6Al 4V withvarying volume fractions of primary 0 10 20 40 50 and 90 was also investigatedin NaCl and HCl solutions The microstructure constituent morphologies and distributions werecharacterized with optical and scanning electron microscopy while constituent compositionswere determined with energy dispersive X ray EDX analysis All microstructures exhibitedspontaneous passivity in 0 9 NaCl at 37 C and active passive transitions in 5 HCl at roomtemperature Very little difference in corrosion rate was observed using potentiodynamicpolarization curves and weight loss tests for four different microstructures Furthermore thefriction stir welded samples exhibited superior corrosion behavior compared to the base metaland arc welded samples The inferior corrosion resistance of the arc weldment was attributed tothe acicular and microstructure and alloying element partitioning between the phases Also the FSP sample exhibited more attack than the FSP sample which could be related to the volume fraction increasing as well as coarsening of phase It was found that the volumefraction and spatial distribution of the microstructural constituents in titanium alloys alongwith elemental partitioning to their respective phases during high temperature exposure are themain factors influencing the corrosion performance of different Ti 6Al 4V microstructures Keywords Ti 6Al 4V alloy Corrosion Microstructure Friction stir welding Gastungsten arc welding IntroductionTitanium alloys are generally classified into three different categories and alloys The alloys are the most widely used because of the wide range ofmicrostructural features that can be created by different thermomechanical processingand heat treatments 1 The strength to weight ratio excellent corrosion resistance andbiocompatibility of Ti alloys have led to the use of these alloys as structural materials inaircraft chemical petrochemical and biomedical applications The microstructure of Tialloys depends on the alloy composition heat treatment and thermomechanicalprocessing history Most of the recent works to develop different microstructures have focused on themechanical behavior The effects of microstructure on the corrosion properties of
استاد راهنما :
محمد حسين فتحي، مرتضي شمعانيان
استاد داور :
محسن صارمي، فرشيد كاشاني بزرگ، محمدعلي گلعذار
