بررسی تأثیر فرایند اکستروژن در کانال‌های هم‌مقطع زاویه‌دار بر ریزساختار و خواص مکانیکی آلیاژ برنج 60-40

نویسندگان

دانشکده مهندسی مواد، دانشگاه صنعتی اصفهان، اصفهان

چکیده

اکستروژن در کانال‌های هم‌مقطع زاویه‌دار، یکی از روش‌های معروف برای تولید مواد ریزدانه به‌شمار می‌آید. در این مطالعه، خواص مکانیکی آلیاژ برنج ‌‌دو فازی 60 – 40 تحت فرایند اکستروژن در کانال‌های هم مقطع زاویه‌دار بررسی شد. به این منظور نمونه‌ها تا کرنش معادل 2 در دمای 350 درجه سانتی‌گراد در مسیر C (پس از چرخش نمونه به اندازه 180 درجه بین پاس‌ها) تحت فرایند اکستروژن قرار گرفتند. ریزساختار نمونه‌ها نشان داد که دانه‌های ریزی در مرزها تشکیل شدند که بیانگر وقوع تبلور مجدد در پاس‌های مختلف بود. مشاهده مسیرهای لغزش در ریزساختار نمونه‌ها نشان داد که حتی در چنین آلیاژی با انرژی نقص چیدن کم، لغزش نابجایی‌ها آغازگر تغییر شکل هستند. بررسی خواص مکانیکی نمونه‌ها نشان داد که با افزایش تعداد پاس، استحکام کششی، میکروسختی و انعطاف‌پذیری به‌صورت هم‌زمان افزایش یافت.

کلیدواژه‌ها


عنوان مقاله [English]

Investigating the Effect of Equal Channel Angular Extrusion on Microstructure and Mechanical Properties of the 60-40 Two-phase Brass Alloy

نویسندگان [English]

  • S. E. Mousavi
  • M. Meratian
  • A. Rezaeian
Department of Materials Engineering, Isfahan University of Technology, Isfahan Iran
چکیده [English]

Equal Channel Angular Pressing (ECAP) is currently one of the most popular methods for fabricating Ultra-Fine Grained (UFG) materials. In this study, mechanical properties of the 60-40 two phase brass processed were evaluated by ECAP. The samples were repeatedly ECAP-ed to strains as high as 2 at a temperature of 350 ◦C using route C. The microstructure of the samples showed that small grains were formed in the boundaries which indicates the occurrence of recrystallization in different passes. Observation of slip trace in the microstructure of the samples showed that even in such alloy with a low-stacking fault energy, dislocations slip trigger the deformation. Investigation of mechanical properties showed that with increasing the number of passes, tensile strength, microhardness and ducility improved at the same time.
 

کلیدواژه‌ها [English]

  • Equal Channel Angular Pressing (ECAP)
  • Two phase brass alloy
  • Severe plastic deformation
  • Strength
  • microstructure
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