7544

7016

كارشناسي ارشد

مهندسي مواد

اصفهان: دانشگاه صنعتي اصفهان، دانشكده مواد

1391

سيزده،121ص.: جدول،نمودار ﴿رنگي﴾

ص.ع.به فارسي و انگليسي

بهزاد نيرومند

12/12/91

مهدي احمديان، علي مالكي

مهندسي مواد

ID7016

به فارسي و انگليسي: قابل رويت در نسخه ديجيتالي

122 Investigating the feasibility of producing A356 CNT open cell nanocomposite foam by melt squeezing technique Ramin Jamshidi Alashti r jamshidialashti@ma iut ac ir January 20 2013 Department of Materials Engineering Isfahan University of Technology 84156 83111 Isfahan Iran Degree M Sc Language FarsiSupervisor Dr Behzad Niroumand Assoc Prof E mail behzn@cc iut ac irAbstractIn this research feasibility of producing A356 CNT nanocomposite open cell foam via meltsqueezing technique was investigated Open cell aluminum foams have gained some significantapplications in various industries because of their specific structural and mechanical characteristics Success in producing CNT incorporated open cell aluminum alloy foams based on castingapproach can ascertain their usage in more critical applications and also their mass production Toachieve this goal this project was conducted in three sections At the first section the influentialparameters for production of open cell A356 aluminum alloy foams via the melt squeezingprocedure was optimized and effects of foam making variables on mechanical properties of theresultant foams were assessed The influence of cell size and piston pressure on the porosity andmechanical properies of final foams was also simulated using artificial neural network ANN Atthe second section various techniques for producing aluminum alloy based nanocompositescontaining different CNT weight percentages were utilized and the optimal one was selected Finally the possibility of producing aluminum based nanocomposite foam using the optimalparameters of the two preceding stages was investigated The results showed that foams comprisingcoarse and fine cell sizes yielded the highest strength and the highest energy absorption capacity respectively Production of bulk nanocomposites were only materialized by applying melt stirringspeeds of more than 2000 rpm Among variant amounts of the reinforcement incorporated into themelt the composite containing 1 wt CNT and 1 wt Ti showed the best mechanical properties including shear bending and compressive strengths among which the bending strength wasimproved by about 27 in comparison with the monolithic casting However due to theinconsistencies amongst the foam optimum production parameters and those of the bulknanocomposite production of nanocomposite foam as the ultimate purpose of this thesis was notfeasible The non practicability of using high stirring speed as well as lack of rapid solidificationcondition in the foam making procedure which results in CNT segregation were recognized as themost important reasons for this failure Key Words Open cell aluminum foam A356 CNT nanocomposite nanocomposite foam vortexcasting mechanical properties microstructure artificial neural network

بهزاد نيرومند

مهدي احمديان، علي مالكي