3474

3280

كارشناسي ارشد

خوردگي و حفاظت از مواد

اصفهان: دانشگاه صنعتي اصفهان، دانشكده مواد

1385

چهار، 128، [II] ص.: مصور، جدول، نمودار

ص. ع. به فارسي و انگليسي

محمدعلي گلعذار، فتح اله كريم زاده

بهزاد نيرومند

15/2/86

احمد ساعتچي، عبدالمجيد جعفري

1396/03/01

كتابنامه

مواد

مهندسي مواد

ID3280

به فارسي و انگليسي: قابل رويت در نسخه ديجيتال

139AbstractSemi solid forming technology has advantages over other conventional forming processessuch as Die cast and Squeeze cast Thixoforming technology can produce non dendriticalloys for the semi solid forming of complex shaped parts in metalic alloys Mechanicaland corrosion properties of the semi solid components can be improved by processingparameters such as solid fraction of the material forming temperature and percentage ofhot working In the research work presented here a 60 percent solid fraction rheocastalloy was reheated to 590 C or 600 C held about 10 minutes and then hotworked by 30 or 50 reduction of cross section These samples were then heat treated by annealing at530 C for 1 h followed by quenching in water and then aging at 160 C for 6h For thestudy of pitting corrosion behavior linear sweep voltammetric and potentiostatic tests wereperformed on thixoformed and rheocast A356 alloy in a 3 5 NaCl solution Microstructure corrosion behavior and mechanical properties of the alloys before andafter heat treatment were then investigated Results obtained show that the tensile strength yield strength and elongation to failure of the alloy thixoformed at 590 C were greaterthan that thixoformed at 600 C Moreover the tensile strength yield strength andelongation to failure of the thixoformed alloy were higher than those of the rheocast andgravity cast samples The improvement in the mechanical properties due to thixoforming isattributed to morphological aspects of the silicon phase as well as to the non dendriticstructure produced Results obtained also show that heat treatment cycle improved tensilestrength and yield strength of thixoformed rheocast and gravity cast samples but reducedelongation to failure of thixoformed rheocast and gravity cast samples Heat treatmentcycle improved pitting corrosion behavior of rheocast and gravity cast samples butreduced pitting corrosion behavior of thixoformed samples Changes in pitting corrosionresistance due to heat treatment cycle is attributed to morphological aspects of siliconphase as well as the area effect as related to galvanic corrosion between siliconparticle cathode and eutectic aluminum phase anode

محمدعلي گلعذار، فتح اله كريم زاده

بهزاد نيرومند

احمد ساعتچي، عبدالمجيد جعفري