‎محمدحسن عباسي، محمدعلي گلعذار

1396/10/04

كتابنامه

مواد

مهندسي مواد

ID9651

به فارسي و انگليسي

74Development of the bimodal nano structure in Al Zn alloys and evaluation of their properties Maryam Davudi Jamaloee m davudi@ma iut ac ir Date of submission 7 July 2015 Department of Materials Engineering Isfahan University of Technology Isfahan 84156 83111 IranDegree M Sc Language FarsiSupervisor karimzadeh f@cc iut ac irena78@cc iut ac irAbstractNanocrystalline alloys have more strength in comparison to conventional coarse grainalloys while they exhibit lower ductility This decrease in ductility can be improved bybimodal size distribution of grains combination of nano and micro grains In a bimodal microstructure nanocrystalline grains increase the strength whilemicrocrystalline grains improve the strain hardening and ductility Al Zn alloys Al 7000class have wide applications in several fields such as military and aerospace industriesdue to their unique properties This research investigates the synthesis of bimodalnanocrystalline Al 6 Zn alloy Nanocrystalline Al Zn powder was synthesized viamechanical alloying method X ray diffraction method was used for phase analysing andscanning electron microscopy for microstructured examinations The results showed thatafter 50 hour of milling time the grain size decreased to 38 5 nm To produce bimodalstructure 30 and 60 wt of nanocrystalline powders was mixed with pure unmilled Alpowder and then was consolidated by spark plasma sintering and hot rolling The porositycontent of consolidated powder was 3 6 The tensile tests showed that the yield stress ofbimodal was 127 Mpa Comparison to pure Al the yield stress increased by 167 and323 and ultimate tensile stress increased by 66 and 143 with an increase innanocrystalline weight percent from 30 to 60 respectively However ductility reducedby 72 8 and 78 respectivelyKey words Bimodal structure Al alloys Mechanical alloying Spark plasma sintering hot rolling

محمدحسين عنايتي، فتح اله كريم زاده

‎محمدحسن عباسي، محمدعلي گلعذار