5916

5531

كارشناسي ارشد

مهندسي مواد

اصفهان: دانشگاه صنعتي اصفهان،دانشكده مواد

1389

ده،140ص.: مصور،جدول،نمودار

ص.ع.به فارسي و انگليسي

بهزاد نيرومند

25/2/90

مهدي احمديان، رحمت ا... عمادي

مهندسي مواد

ID5531

به فارسي و انگليسي: قابل رويت در نسخه ديجيتالي

Fabrication and characterization of Al356 SiCp semi solid composite produced by injection of SiCp containing composite powders Sajjad Amirkhanlou s amirkhanlou@ma iut ac ir 13th April 2010 Department of Materials Engineering Isfahan University of Technology 84156 83111 Isfahan Iran Degree M Sc Language Farsi Dr Behzad Niroumand Assoc Prof Supervisor E mail behzn@cc iut ac ir Abstract In the present work Al356 SiCp composites were produced by stir casting and compocasting techniques SiC particles were injected into the melt in three forms of SiCp powder or Al SiCp and Al SiCp Mg composite powders The composite powders were produced by low energy ball milling of SiCp Al and Mg powders The effects of the type of the injected powder and the casting method on the porosity microstructure distribution and incorporation of the reinforcement particles as well as their macro and micro hardness wear resistance tensile properties in low and high temperatures impact strength and three point bending strength were investigated The results revealed that addition of SiCp particles in the form of composite powders and casting in semisolid state decreased the SiCp particle size porosity and grain size enhanced the wettability between the molten matrix alloy and the reinforcements and improved the distribution of the reinforcement particles in the solidified matrix Simultaneous utilization of the advantages of injection of Al SiCp Mg composite powder and semi solid processing reduced the porosity content of the cast composites by 78 and increased their incorporated reinforcement by about 83 As a result macro and micro hardness and tensile properties of the composites were also increased Elastic modulus yield strength ultimate tensile strength and elongation of the composites produced by injection of composite powders was significantly improved compared with the matrix alloy or the composite produced by injection of untreated SiCp While the un reinforced alloy kept less than 70 of its strength at 300 C the composites samples kept more than 90 of their strength at this temperature The impact energy and bending strength of all composite samples were reduced compared to those of the matrix alloy but the reduction was less significant for the composites manufactured by injection of composite powders or treatment in semi solid temperature range Furthermore different possibilities for melting of the injected particles of the composite powders and distribution of SiCp in the melt were envisaged and the consequences were discussed considering the possibility of the oxide film on the particles hindering the distribution of the reinforcements Keywords Metal matrix composite Al356 SiCp Composite powder Stir casting Compocasting Microstructure Mechanical properties High temperature tensile strength

بهزاد نيرومند

مهدي احمديان، رحمت ا... عمادي