5223

4894

كارشناسي ارشد

شناسايي و انتخاب مواد

اصفهان: دانشگاه صنعتي اصفهان، دانشكده مواد

1388

سيزده،75ص.:مصور،جدول،نمودار

ص.ع.به فارسي و انگليسي

محمود مرآتيان، غلامرضا آريانپور

مسعود پنجه پور

8/3/89

بهزاد نيرومند،مهدي احمديان

1396/09/29

كتابنامه

مهندسي مواد

ID4894

به فارسي و انگليسي: قابل رويت در نسخه ديجيتالي

Fabrication of magnesium matrix composites by pressure infiltration casting to ceramic preform Bahman Eghtedari Email address b eghtedari@ma iut ac ir Date of Submission Department of Materials Engineering Isfahan University of Technology Isfahan 84156 83111 Iran Degree M Sc Language Farsi Supervisor s Name Mahmoud Meratian Associate Professor meratian@cc iut ac ir Gholam reza Aryanpour Assistant Professor aryanmat@cc iut ac ir Advisor s Name Masoud Panjepour Assistant Professor mdpanjehpour@cc iut ac ir Abstract In recent years magnesium matrix composites due to their low density and high specific strength are used extensively in automobile and space industry One of the advanced routes for manufacturing the magnesium matrix composites is infiltration casting into ceramic foams In this research magnesium matrix composite AZ91 Al2O 3 production has been investigated Therefore AZ91 alloy molten is prepared by usage of torch furnace under protection of MAGREX flux then poured in preheated mould at 250 C with preheated alumina foam at 800 C For investigating the casting temperature on the microstructure and mechanical properties melting temperature was set at 700 790 C and then pressures at 50 75 and 100 MPa in 1 minute applied until solidification was completed For comparison similar experiments were done without applying pressure The results showed that solidification under pressure reduced porosity noticeably in comparison with gravity casting to 60 By addition the ceramic reinforcement to the base alloy mechanical strength reduced due to formation of MgAl2O4 spinel phase at interface and formation of residual compression stresses because of thermal mismatch between matrix and reinforcement When experimental temperature is increased 300 C due to enlarging of grain size and alloy flowing the strength of base alloy decreased to 20 of strength at room temperature Although the ductility is not increased sharply 23 Also because of relaxation of residual stresses composite strength is not decreased noticeably in relation with room temperature strength The mechanical strength and ductility of the samples are increased by rising of applied pressure to 0 100 MPa due to decrease grain size and better strength interface of alumina and alloy When pouring temperature is increased strength of alloy and composite and ductility increase ca 17 Additionally wear rate due of composite decreased in comparison to base alloy declined markedly about 53 This may be due to higher intrinsic alumina strength Also by applying pressure on molten metal during solidification wear rate is noticeably lesser than similar gravity sample due to decreasing the grain size and markedly declining the porosity The dominant mechanism for base alloy is adhesive wear and for composite is abrasive wear and delamination Keywords Composite Magnesium Alumina Infiltration casting Spinel phase Wear

محمود مرآتيان، غلامرضا آريانپور

مسعود پنجه پور

بهزاد نيرومند،مهدي احمديان