پديد آورنده :
نواصر، محمد
عنوان :
ارزيابي رفتار خوردگي آلياژ آلومينيوم 7075 پس از فرايند اصطكاكي - اغتشاشي
مقطع تحصيلي :
كارشناسي ارشد
گرايش تحصيلي :
خوردگي و حفاظت از مواد
محل تحصيل :
اصفهان: دانشگاه صنعتي اصفهان، دانشكده مواد
صفحه شمار :
چهارده، 120ص.: مصور، جدول، نمودار
استاد راهنما :
مسعود عطاپور
توصيفگر ها :
خوردگي حفره اي , خوردگي بين دانه اي , سرعت چرخشي , ريزساختار
تاريخ نمايه سازي :
1394/06/07
استاد داور :
علي اشرفي، عليرضا علافچيان
تاريخ ورود اطلاعات :
1396/10/04
چكيده فارسي :
به فارسي و انگليسي
چكيده انگليسي :
Evalution of corrosion behaviour of aluminium alloy 7075 after friction stir processing Mohammad Navaser M Navaser@ma iut ac ir 2015 06 23 Department of Materials Engineering Isfahan University of Technology Isfahan 84156 83111 Iran Degree M Sc Language FarsiSupervisor masoud atapour Assistant Professor m atapour@cc iut ac irAbstractIn this study the effect of rotational speed on the corrosion behavior of 7075 aluminum alloyafter friction stir processing FSP was studied Three FS processed samples were made byemploying a constant tool travel speed of 100 mm min at rotating speeds of 630 1000 and1600 rpm Corrosion behavior of all three samples was evaluated by open circuit potential OCP tafel potentiodynamic polarization cyclic polarization electrochemical impedancespectroscopy EIS immersion intergranular corrosion IGC and exfoliation corrosion Microstructural surveys demonstrated that very fine and equiaxed grain structures wereformed in the stir zones Also FSP at higher rotational speed resulted in an increase in thegrain size a decrease in the intermetallic size and more uniform distribution of them Thetransition zone between thermo mechanically affected zone TMAZ and the stir zoneexhibited recrystallized grains The OCP results indicated the formation of protective filmon the surface of samples Tafel potentiodynamic polarization and EIS tests showed that theFS processed sample with 1600 rpm and base metal exhibited the highest and lowestresistance to corrosion respectively Cyclic polarization test in 3 5 Nacl solution hasdemonstrated that FS processed sample with rotational speede of 1600 rpm and base metalillustrated the best resistance to localized corrosion The observations of Immersion test in3 5 NaCl indicated the formation of bigger and deeper pits in the base metal In contrast the size of each pit was decreased and the number of pits was increased for FSP for in 1600rpm IGC test illustrated that the stir zone of all samples was subjected to a combination ofIGC and pitting corrosion while no IGC was found in other zones Furthermore when therotational speed was increased the corrosion attack was decreased Exfoliation corrosionshowed that stir zone and TMAZ of all samples were prone to IGC and pitting corrosion Moreover heat affected zone HAZ and base metal demonstrated the same corrosionbehavior and were undergone sever localized corrosion Interestingly increase of rotationalspeed improved the corrosion resistance of all zones Generally with the increase of therotational speed the size of intermetallics decreased and their distribution became morehomoginous which led to improvement of the corrosion behavior of FS processed samples Keywords Friction stir processing pitting corrosion intergranular corrosion rotationalspeed microstructure 7075 aluminium alloy
استاد راهنما :
مسعود عطاپور
استاد داور :
علي اشرفي، عليرضا علافچيان
