بررسی تاثیر ضریب کارسختی ماده بر مشخصه های تغییر شکل نمونه در فرآیند پرس در کانالهای زاویه دار هم مقطع

نوع مقاله: مقاله پژوهشی

نویسنده

استادیار، گروه مهندسی مواد، دانشکده فنی و مهندسی، دانشگاه بناب، بناب، ایران.

چکیده

در این تحقیق تاثیر ضریب کارسختی بر روی نحوه سیلان فلز و توزیع کرنش، فاکتور تخریب و نیروی لازم برای پرس نمونه با استفاده از تحلیل المان محدود مورد بررسی قرار گرفت. نتایج حاصل نشان داد در مورد ماده پلاستیک ایده آل منطقه پر نشده از فلز در محل تقاطع کانالها ایجاد نمی شود و کرنش اعمالی به ناحیه پایینی نمونه از سطح بالایی بیشتر است. در حالیکه با افزایش ضریب کارسختی اندازه ناحیه پر نشده افزایش یافته و کرنش کمتری به قسمت پایینی نمونه اعمال می شود. همچنین فاکتور تخریب در نمونه با رفتار پلاستیک ایده آل در سطح بالایی نمونه نسبت به نواحی دیگر بالا بوده و در این ناحیه تنشهای کششی نیز اعمال می شود. برعکس درمورد نمونه ای با رفتار کارسختی، بیشترین فاکتور تخریب مربوط به ناحیه نیمه پایینی نمونه است. از طرفی مشاهده شد با افزایش ضریب کارسختی میزان نیروی لازم برای پرس نمونه کاهش می یابد.

کلیدواژه‌ها


عنوان مقاله [English]

Effect of strain hardening behavior of material on deformation characteristics of samples during equal channel angular pressing

نویسنده [English]

  • mehdi shaban ghazani
Assistant Professor, Department of Materials Science Engineering, University of Bonab, Bonab, Iran.
چکیده [English]

In the present study, the effect of srain hardening exponent os material on flow characteristics, strain and damage distribution in sample and the load requred for the execution of the deformation process was investigated using finite element simulation. Results showed that the corner gap is not formed during deformation of ideally plastic material and the amount of eauivalent strain is higher in the bottom side of sample compared with other regions. However, with increassing the work hardening exponent, the size of corner gap increases and the bottom side recieves less amount of strain. Also, damage factor in the sample of idealy plastic material is higher at the top side compared with other regions and the tensile stresses are aplliyed on this area. Whereas, in the strain hardened material the higher damage factor was observed at the lower half of the sample. Finally. it was concluded that the pressing force increases with increassing the work hardening exponent.

کلیدواژه‌ها [English]

  • Equal channel angular pressing
  • finite element simulation
  • work hardening
  • Damage
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