7588

7060

كارشناسي ارشد

شناسايي و انتخاب مواد

اصفهان: دانشگاه صنعتي اصفهان، دانشكده مواد

1391

سيزده،80ص.: مصور،جدول،نمودار

ص.ع.به فارسي و انگليسي

محمد حسين فتحي، كيوان رئيسي

20/12/91

فخرالدين اشرفي زاده، مهدي احمديان

مهندسي مواد

ID7060

به فارسي و انگليسي: قابل رويت در نسخه ديجيتالي

The Effect of the Type of Nanostructured Fluorhydroxyapatite Coating on the Corrosion Behavior and Biodegradation of Mg alloy as a Human Body Implant Ramin Rojaee raminrojaee@aim com January 5th 2013 Department of Materials Engineering Isfahan University of Technology Isfahan 84156 83111 Iran Degree M Sc Language Farsi Supervisors Mohammad Hossein Fathi Professor fathi@cc iut ac ir Keyvan Raeissi Associate Professor k raeissi@cc iut ac ir Abstract The present investigation is laid on nanostructured fluorhydroxyapatite FHA coatings accompanied with 0 25 and 60 Fluorine F substitution into hydroxyapatite HA crystalline structure on AZ91 magnesium based alloy via sol gel and electrophoretic deposition EPD techniques in order to control magnesium degradation rate for bone implant applications The first step was followed by nanostructured HA coating via sol gel method The coated samples were heat treated up to 400 C for further calcination process Another group of AZ91 samples was anodized by Micro arc oxidation MAO method for the initial surface treatment before EPD FHA powders were prepared using sol gel method The powders were heat treated up to 600 C to synthesize high degree of crystalized powders EPD method was used to apply the FHA powders on AZ91 samples using a methanol FHA suspension bath Results revealed that the sol gel technique is just able to create a pure hydroxyapatite coating on AZ91 samples while EPD is a promising method in fluoridated HA coatings on AZ91 magnesium based alloy specimens All coated samples had a striking bioactive surface according to simulated body fluid SBF immersion test A considerable degree of decrease two times and more in substrate degradation rate has been occurred in all successful coatings Zeta potential conductivity measurements revealed that the homogeneity of FHA coatings will decrease as fluorine percentage increase Electrochemical polarization tests showed a remarkable reduction in corrosion current densities in FHA coated AZ91 samples versus bare AZ91 specimens Among these 25 Fluorine substituted in HA crystalline structure FHA25 coating on AZ91 specimens possesses the best effects on controlling the magnesium degradation rate which is due to the lower solubility of fluoridated HA coatings incorporating higher amount of F Keywords Magnesium Fluorhydroxyapatite Bioactivity Controlling Degradation Rate Micro Arc Oxidation Electrophoretic Deposition

محمد حسين فتحي، كيوان رئيسي

فخرالدين اشرفي زاده، مهدي احمديان