9353

8635

كارشناسي ارشد

مواد- جوشكاري

اصفهان: دانشگاه صنعتي اصفهان، دانشكده مواد

1393

سيزده،101ص.:مصور،جدول،نمودار

ص.ع.به فارسي و انگليسي

محمدحسين عنايتي، فتح ا... كريم زاده

23/9/93

كيوان رئيسي، علي اشرفي

مهندسي مواد

ID8635

104 Effects of friction stir processing on microstructure and mechanical properties of A356 aluminum cast alloy Mohammad Reza Sadeghi Behnoyi Mohammad sadeghi@ma iut ac ir Data of Submission 2014 09 22 Department of Materials Engineering Isfahan University of Technology Isfahan 84156 83111 Iran Degree M Sc Language FarsiSupervisors M H Enayati ena78@cc iut ac irF Karimzadeh f karimzadeh@cc iut ac irAbstractFriction Stir Processing FSP can be utilized to modify the microstructure of the surfacelayer and eliminate solidification defects In this study FSP was used to improve theweldment microstructure and properties of cast A356 aluminum alloy Gas tungsten arcwelding process was used for fusion welding with ER4043 filler metal and negativepolarity FSP was applied along the longitudinal direction of the weld with rotational andlinear speed of 1000 RPM and 100 mm min based on previews studies To determine thephases produced during the process X ray diffraction XRD and X ray spectrometer EDS was used The microstructure of samples studied by conventional light microscopyand scanning electron microscopy SEM To evaluate the abrasion resistance a wear testwith a constant load of 10 N was applied Microstructural evaluations showed that FSPdestroyed the coarse dendritic microstructure and dissolved the secondary Al5FeSi hardand brittle phase existing at grain boundaries of weld zone Metallographical examinationshowed more homogeneous eutectic silicon was obtained zone compared to the base metalindicating the greater influence of the FSP process in breaking and depressing of siliconthe base metal ratio Distribution of hardness in the samples show increased hardness ofthe base metal weld metal FSP aftar in the weld and T6 heat treatment the sample at of55 59 78 and 80 Vickers Tensile test results indicate a dramatic increase in yieldstrength tensile strength and ductility of the samples after FSP The tensile strength of theStir Zone SZ is also greatly elevated and shows over 178 MPa i e almost 37 that of thebase metal Wear test results showed that the FSP increases the wear resistance of thesamples The wear mass loss of the SZ is also greatly elevated and shows over 0 02mg andthat of the BM Keywords Optimize Repair weld Friction stir processing GTAW A356

محمدحسين عنايتي، فتح ا... كريم زاده

كيوان رئيسي، علي اشرفي