تاثیر زمان نگهداری و قطر شانه ابزار بر استحکام و رفتار شکست فرآیند جوشکاری اصطکاکی اغتشاشی نقطه‌ای زائده‌ای آلیاژآلومینیوم 2024

نوع مقاله : مقاله پژوهشی

نویسندگان

1 دانشجوی کارشناسی ارشد، دانشکده فنی و مهندسی، دانشگاه حکیم سبزواری، سبزوار، ایران

2 استادیار، دانشکده فنی و مهندسی، دانشگاه حکیم سبزواری، سبزوار، ایران

3 دانشیار، دانشکده فنی و مهندسی، دانشگاه حکیم سبزواری، سبزوار، ایران

4 - استادیار، دانشکده فنی و مهندسی، دانشگاه فناوری های نوین سبزواری، سبزوار، ایران

چکیده

در پژوهش حاضر، یک تکنیک جدید از روش جوشکاری اصطکاکی اغتشاشی نقطه­ای با هدف حذف فرورفتگی مورد بررسی قرار گرفته است. این روش در مورد ورق­های آلیاژ آلومینیوم 2024 با ضخامت 1میلی متر، تحت اثر سرعت چرخش ثابت و با تغییر قطر شانه ابزار و زمان نگهداری ابزار انجام شده است. اثر قطر شانه و زمان  نگهداری ابزار بر خواص مکانیکی مورد ارزیابی و بحث قرار گرفته است. ارزیابی­ها نشان می­دهد که این روش جدید دارای قابلیت ایجاد فصل مشترک متالورژیکی بدون عیب به همراه ساختار همگن و دانه ریز در ناحیه جوش می­باشد. به­گونه­ای که اندازه دانه از 21 میکرومتر در فلز پایه به 5 میکرومتر در ناحیه همزده کاهش یافته و نیز اتصالات، نیروی شکست بالاتر از 6000 نیوتون را نشان دادند.  سطح اتصال، عمق ناحیه همزده، ضخامت ورق بالا، هندسه هوک، اندازه دانه و ذوب موضعی از جمله عوامل اثر گذار بر خواص مکانیکی هستند که با تغییر پارامترهای فرآیند تغییر می­کنند.

کلیدواژه‌ها


عنوان مقاله [English]

Effect of the shoulder size and dwell time on the static Strength and fracture mode of projection friction stir spot welded 2024 aluminum alloy

نویسندگان [English]

  • F. zarghani 1
  • seid m. mousavizade 2
  • G.R Ebrahimi 3
  • H.R. Ezatpour 4
1 - M.Sc.Student, Department of Materials and Polymer Engineering, Hakim Sabzevari University, Sabzevar, Iran
2 Assistant Professor, Department of Materials and Polymer Engineering, Hakim Sabzevari University, Sabzevar, Iran
3 - Association Professor, Department of Materials and Polymer Engineering, Hakim Sabzevari University, Sabzevar, Iran
4 Faculty of Engineering, Sabzevar University of New Technology, Sabzevar, Iran
چکیده [English]

      Automotive industry has developed a variant of the Friction Stir Welding named Friction Stir Spot Welding (FSSW), to replace resistance spot welding (RSW) for aluminum sheets. It is claimed that the use of energy and the investment cost are decreased with using of friction stir spot welding in comparison with resistance spot welding. However, one of the disadvantages of FSSW technique is that a keyhole generally remains at the center of the stir zone. Keyhole defect can reduce the mechanical properties of FSSW joints. A novel friction stir spot welding technique was developed with the purpose to improve the mechanical property of the joints by removing the keyhole. This novel FSSW method was applied to 2024 Al alloy sheets, 1 mm in thickness, under different shoulder size and dwell times. The effect of shoulder size and dwell time on the mechanical properties of the spot joints has been studied. Studies show that this new spot welding technique can produce a defect-free metallurgical bond with a homogenous fine grain microstructure. The welding parameters variations change the bonding area, depth stir zone, upper sheet thickness, grain size and mechanical properties of the welds.

کلیدواژه‌ها [English]

  • Friction stir spot welding
  • 2024Aluminium alloy
  • mechanical properties
  • Fracture mode
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