2443

2463پ

2441

كارشناسي ارشد

(شناسائي وانتخاب مواد)

اصفهان: دانشگاه صنعتي اصفهان، دانشكده مواد

1383

يازده، 70ص.: مصور، جدول، شكل، نمودار

بهزاد نيرومند، عباس نجفي زاده

29/07/83

1396/02/24

كتابنامه

مواد

مهندسي مواد

ID2441

به فارسي (قابل رويت درقسمت "نسخه ديجيتال ")،ونيزبه انگليسي

AbstractThe objective of this study is to investigate the effects of some processing parameterson the microstructural features of semisolid cast billets First of all the effect of solidfraction and stirrer speed was studied on the microstructure of Al 7 1 Si rheocast alloy then the most appropriate microstructure was selected with respect to certain criteria andits experimental conditions were applied to Al 11 6 Si alloy The results confirm thatthe size of primary particles and its arms increases with increasing solid fraction anddecreasing stirrer speed The particle circularity increases with decreasing solid fractionat any given stirrer speed At any given solid fraction circularity first increases byincreasing stirrer speed from 500 to 1000 rpm However by increasing the stirrer speedfrom 1000 to 2000 rpm the circularity of the particles decreases The porosity contentof the samples increase with increasing stirrer speed however at a constant stirrerspeed the 24 solid fraction sample exhibited the highest amount of porosity Thechemical composition was found to affect the detectability of the primary particles inthe microstructure Two mechanisms were used to explain the observed microstructuralchange behavior These mechanisms are agglomeration disagglomeration and nucleation and separation of particles from crucible wall

بهزاد نيرومند، عباس نجفي زاده