4855

4559

كارشناسي ارشد

شناسايي و انتخاب مواد

اصفهان: دانشگاه صنعتي اصفهان، دانشكده مواد

1388

نه،98ص.: مصور،جدول،نمودار

ص.ع.به فارسي و انگليسي

محمدعلي گلعذار

فتح ا.. كريم زاده

28/9/88

محمود منيرواقفي،محمدحسين عنايتي

مهندسي مواد

ID4559

به فارسي و انگليسي: قابل رويت در نسخه ديجيتالي

Development of Mg Al2O3 Nano composite on the surface of Mg AZ31 alloy and Its Characterization Ali Shahnam A shahnam@ma iut ac ir April 8 2009 Department of materials science Isfahan university of technology Isfahan 84156 8311 Iran Degree M sc Language farsi Supervisor name M A Golozar golozar@cc iut ac ir Abstract In this research the Mg AZ31 B alloy was submerge friction stir processed SFSP and the effects of pin rotation speed and traverse speed V on microstructure texture and abnormal grain growth AGG were investigated Also variations of grain size and hardness of stir zone were identified In addition SFSP was applied to incorporate nano sized Al2O3 into an AZ31 magnesium alloy matrix to form composite surface layer Samples were subjected to SFSP with and without Al2O3 particles Microstructural observations were carried out by employing optical and scanning electron microscopy SEM on the cross sections both parallel and perpendicular to the tool traverse direction In addition X ray diffraction was used to determined grain orientation distribution The relationship between the resulting grain size the applied working strain rate and temperature for submerge friction stir processing in AZ31 B was also examined systematically Results showed that ultra fine grain UFG microstructures with an average grain size less than 1 m could be achieved in a solid solution of hardened AZ31 B magnesium alloy The mean hardness of the stir zone reached about 95 HV which is more than twice as high as that of the base metal When rotation speed decreased or traverse speed increased texture strengthened and abnormal grain growth increased Microstructural observations showed that reasonably uniform distribution of reinforcement lead to significant grain refinement of AZ31 magnesium alloy matrix and effectively restricted the grain growth at elevate temperatures such as 400 C Mechanical characterization revealed that addition of nano Al2O3 particles as reinforcement improves microhardness and wear resistance of magnesium alloy Results obtained from electrochemical corrosion tests revealed that presence of Al2O3 in the surface of AZ31 B alloy increased the corrosion rate in 3 5 NaCl solution Key Words Magnesium alloy SFSP AGG nano composite UFG Microstructure pdfMachine A pdf writer that produces quality PDF files with ease Produce quality PDF files in seconds and preserve the integrity of your original documents Compatible across nearly all Windows platforms if you can print from a windows application you can use pdfMachine Get yours now

محمدعلي گلعذار

فتح ا.. كريم زاده

محمود منيرواقفي،محمدحسين عنايتي