7587

7059

كارشناسي ارشد

ريخته گري

اصفهان: دانشگاه صنعتي اصفهان، دانشكده مواد

1391

دوازده،73ص.: مصور،جدول،نمودار

ص.ع.به فارسي و انگليسي

محمودمرآتيان، غلامرضا آريانپور

كيوان رئيسي

20/12/91

علي شفيعي، مسعود عطاپور

مهندسي مواد

ID7059

به فارسي و انگليسي: قابل رويت در نسخه ديجيتالي

Casting and Electrochemical Characterization of Indium Activated Aluminum Sacrificial Anodes Muhammad Pourgharibshahi M pourgharibshahi@ma iut ac ir Date of Submission 23 December 2012 Department of Materials Engineering Isfahan University of Technology Isfahan 84156 83111 Iran Degree M Sc Language Persian Supervisers M Meratian Assoc Prof G Arianpour Assist Prof Abstracts Aluminum owning to its high theoretical current capacity 2980 A hr kg in one hand and its low density and low price on the other hand is a good candidate material for fabricating galvanic or sacrificial anodes However the protective oxide layer which forms on the surface of pure aluminum causes to lower its closed circuit potential in sea water making it no longer been useful for protecting steel structures In order to lower anodic polarization properties many alloys with different chemical compositions have developed Except several exceptions all alloys developed for removing the passive film had been empirical caused to develop a number of appropriate commercial alloys which are currently used in cathodic protection systems The chemical compositions of sacrificial anodes alloy are generally privative and patented These documents are too imprecise in expressing chemical composition and wrong in the effect of an especial alloying element Producing high performance anodes is so dependent on the purity of aluminum primary materials and adding zinc and indium as main alloying elements In order to overcome disadvantages of using low purity aluminum materials which reduce production costs in recent two decades many researches have been done aiming at finding some new additive agents Cathodic protection of offshore platforms and oil and gas pipelines in waters of Islamic Republic of Iran also requires these anodes For this several tons of aluminum anodes are imported from abroads to Iran annually taking out too much exchange Presently only small fraction of this requirement is supplied by internal factories which reports indicate the quality of these anodes is not satisfactory In order to improve the quality of internal produced aluminum galvanic anodes in this research an imported anode was characterized and using obtained information a method for fabricating high performance anodes was introduced The electrochemical performances of all samples representative and cast samples were examined by short term tofel tests and an electrochemical test according to standard of DNV Microstructure and corrosion morphology of the samples were examined by optical and scanning electron microscopy It is found that producing high performance aluminum anodes by pouring the melt in metal molds need several alloying elements such as silicon magnesium and calcium other than just zinc and indium Finally a new cast aluminum sacrificial anode with appropriate electrochemical properties and nominal chemical composition of Al 5 5 Zn 0 3 Si 0 1 Mg 0 1 Ca 0 02 In was introduced Keywords sacrificial anode cathodic protection aluminum alloy electrochemical properties Corrosion morphology Al Zn In casting Indium activated cast aluminum anode

محمودمرآتيان، غلامرضا آريانپور

كيوان رئيسي

علي شفيعي، مسعود عطاپور