بررسی نقش دوقلویی‌ها بر تغییرات بافت آلیاژ منیزیم AZ63 حین کار گرم
محورهای موضوعی : فصلنامه علمی - پژوهشی مواد نوینمهدی کاویانی 1 , غلامرضا ابراهیمی 2
1 - دانشجوی کارشناسی ارشد، دانشکده فنی و مهندسی، دانشگاه حکیم سبزواری، سبزوار، ایران
2 - دانشیار، دانشکده فنی و مهندسی، دانشگاه حکیم سبزواری، سبزوار، ایران
کلید واژه: آلیاژ منیزیم AZ63, بافت, دوقلویی, تبلور مجدد دینامیکی,
چکیده مقاله :
به منظور بررسی تاثیر بافت اولیه و پارامترهای ترمومکانیکی بر رفتار کار گرم آلیاژ منیزیم AZ63، رفتار سیلان ماده، بافت تغییر شکل حاصل از فشار گرم نمونه‌های ریختگی و نمونه‌های اکسترود شده با یکدیگر مقایسه شده است. نمونه‌های اکسترود شده در دو جهت اکسترود و جهت نرمال ماشین کاری شدند. آزمون‌های فشار گرم در دمای C° 250 و نرخ کرنش‌های s-1 1 و s-1 01/0 و کرنش‌های متفاوت انجام شدند. مشاهدات ریزساختاری و بررسی بافت‌ها در شرایط تغییر شکل متفاوت نشان دهنده این است که حضور دوقلویی‌های کششی و فشاری در نمونه‌های اکسترود شده و دوقلویی‌های کششی در نمونه‌های ریخته گری شده، تاثیر به سزایی در تغییرات بافت نمونه‌ها در کرنش‌های اولیه تغییر شکل و هم‌چنین تبلور مجدد در کرنش‌های پایانی نمونه‌های اکسترود شده داشته است.
To investigate the influence of primary texture and thermomechanical parameters on hot working behavior of AZ63 magnesium alloy, the flow behavior and deformation texture of hot compression test was compared for both cast and extruded samples. The extruded samples were machined in two extruded and normal directions. Compression tests were carried out at 250 °C and the strain rate of 1 s-1 and 0.01 s-1 and various strains. Microstructural observations and texture investigation in various conditions reveal that the presence of extensive twins and contraction twins in extruded samples and extensive twinning in cast samples at primary deformation strains and recrystallization at final strains of extruded samples have a significant influence on texture evolutions. .
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