5224

4893

كارشناسي ارشد

مهندسي مواد

اصفهان: دانشگاه صنعتي اصفهان، دانشكده مواد

1388

ده،107ص.:مصور﴿بخش رنگي﴾،جدول،نمودار

ص.ع.به فارسي

محمدحسين عنايتي،فتح ا... كريم زاده

8/3/89

محمدحسين عنايتي،محمدحسين فتحي

1396/09/29

كتابنامه

مهندسي مواد

ID4893

به فارسي و انگليسي: قابل رويت در نسخه ديجيتالي

Formation mechanism of Fe Ti 3Al Al2O3 nanocomposite by mechanical alloying Mahdi Rafiei Email address rafiei mahdi@yahoo com Date of Submission Department of Materials Engineering Isfahan University of Technology Isfahan 84156 83111 Iran Degree M Sc Language Farsi Supervisor s Name Mohammad Hossein Enayati Associate Professor ena78@cc iut ac ir Fathollah Karimzadeh Associate Professor karimzadeh f@cc iut ac irAbstractFe3Al intermetallic compound has several advantages such as high hardness high melting point relativelylow density and high temperature oxidation resistance The main problems of this compound areembrittlement at room temperature low creep resistance at high temperatures and low strength at T 600oC These problems can be overcome by adding third alloying element like Ti decreasing crystallite size anduniform distribution of fine stable particles in the matrix The aim of this research was to synthesis Fe Ti 3Al Al2O3 nanocomposite by mechanical alloying MA The formation of Fe Ti 3Al intermetallic compound by MA was first considered and evaluated bythermodynamic analysis of Fe Al Ti ternary system using semi empirical miedema s model In next step Fe Ti 3Al Al2O3 nanocomposite was synthesized by utilizing the displacement reactions of Al TiO2 and Al Fe2O3 during mechanical alloying X ray diffractometry XRD scanning electron microscopy SEM differential thermal analysis DTA and microhardness measurements were used to characterize powderparticles after different milling times MA of Fe Al Ti powder mixture with molar ratio of Fe50Al25Ti25 led to the formation of Fe Al Ti solidsolution and which transformed to nanocrystalline Fe Ti 3Al intermetallic compound with DO3 structureafter 100h of milling time Heat treatment of this compound at 550oC for 1h led to the formation of orderedstructure Thermodynamic analysis of Fe Al Ti ternary system indicated that substitution of Ti for Fe inFe3Al compound reduces the Gibbs free energy and therefore Fe3Al compound is more stable compoundcompared to Fe Ti 3Al compound MA of Fe Al TiO2 powder mixture formed Fe Ti 3Al Al2O3 nanocomposite by gradual reaction of TiO2 andAl It was found that this reaction occurs in 2 stages reduction of TiO2 by Al and then formation of Fe Ti 3Al compound Fe Ti 3Al Al2O3 nanocomposite was obtained after 5h mechanical alloying of Al Ti Fe2O3 powder mixture Fe2O3 Al reaction occured with a combustion mode in this system Also MA of Fe Al Ti Fe2O3 powdermixture led to the formation of Fe Ti 3Al Al2O3 nanocomposite by gradual reduction of Fe2O3 by Al Theproducts of this reaction were disordered Fe Ti 3Al intermetallic compound and amorphous Al2O3 Heattreatment of this compound at 900oC for 1h led to the crystallization of Al2O3 and ordering of Fe Ti 3Alcompound KeywordsIntermetallic matrix nanocomposite Fe Ti 3Al Al2O3 Mechanical alloying Thermodynamic analysis Reaction kinetic

محمدحسين عنايتي،فتح ا... كريم زاده

محمدحسين عنايتي،محمدحسين فتحي