عنوان :
تاثير روزافزون ردياز عنصر قلع به حمام آبكاري، بربافت، مرفولوژي و خواص خوردگي پوشش هاي الكتريكي روي
مقطع تحصيلي :
كارشناسي ارشد
گرايش تحصيلي :
خوردگي و حفاظت از مواد
محل تحصيل :
اصفهان: دانشگاه صنعتي اصفهان، دانشكده مواد
صفحه شمار :
ده، 144، [II]ص.: مصور، جدول، نمودار
يادداشت :
ص.ع. به: فارسي و انگليسي
استاد راهنما :
كيوان رئيسي، احمد ساعتچي
توصيفگر ها :
هيدروكسيد روي , ولتامتري , امپدانس الكتروشيميايي , پلاريزاسيون تافل
تاريخ نمايه سازي :
11/03/87
استاد داور :
محمد علي گلعذار، ابوالقاسم دولتي
چكيده فارسي :
به فارسي و انگليسي: قايل رؤيت درنسخه ديجيتال
چكيده انگليسي :
Abstract Zinc coatings were deposited from sulfate bath containing 10 and 100 ppm Sn2 onmechanically and electrolytically polished low carbon steel substrate The current densitiesused were 10 100 200 and 400 mA cm2 Cyclic Voltametery and cathodic sweep resultsshowed that hydrogen evolution rate on electrolytically polished surface is more than thaton mechanically polished surface in the presence of 10 and 100 ppm Sn2 Hydrogenevolution rate on steel substrate and Zn electrodeposition overpotential with 100 ppm Sn2 are more than those with 10 ppm Sn2 Besides this Zn reduction with 10 ppm Sn2 iseasier Correlation between nucleation modes of deposits in different conditions andScharifker model was studied Calculation of surface diffusion coefficient of Zn ions in 10ppm Sn2 contained bath by Scharifker equations showed that surface diffusion of Zn ionson electrolytic polished surface in 100 and 200 mA cm2 is about 35 and 31 times greaterthan that on mechanically polished surface respectively In addition increasing the currentdensity increases surface diffusion coefficient of Zn2 ions on both mechanically andelectrolytically polished surfaces Coatings texture calculation with X ray diffractionpatterns revealed that 00 2 basal plane in 100 200 and 400 mA cm2 current densities andlow angle pyramidal plane in 10 mA cm2 are main texture component in coatings obtainedfrom bath containing 10 ppm Sn2 on electrolytically polished surface Pyramidal texturecomponent in 10 100 and 200 mA cm2 current densities and 00 2 basal plane in 400mA cm2 are main texture component in coatings obtained from bath containing 10 ppmSn2 on mechanically polished surface 00 2 basal plane and 11 4 10 2 10 3 10 4 and 10 5 pyramidal planes are texture components in coatings obtained from 100ppm Sn2 contained bath on both mechanically and electrolytically polished surfaces andhigh angle pyramidal plane intensity increases with increasing current density Tafelpolarization test results in deaerated 0 5 wt NaCl solution revealed that anodic branchesare partially same but cathodic branches are very different Potentiostatic tests in 1000 mVanodic potential and 1350 mV cathodic potential revealed that crystallographicorientations difference is effective on hydrogen evolution rate and has no effect on Zndissolution rate Comparison of correlation between coatings texture and morphology withcorrosion properties revealed that coatings texture cannot be the determining parameter oncorrosion resistance Further analysis revealed that corrosion properties must be related toplanes exposed to solution porosity and effective surface Electrochemical ImpedanceSpectroscopy EIS results and corrosion process simulation showed that Zn corrosionbehavior is same to equivalent circuit for pore oxide film
استاد راهنما :
كيوان رئيسي، احمد ساعتچي
استاد داور :
محمد علي گلعذار، ابوالقاسم دولتي
