تأثیر سرعت چرخشی ابزار بر ریزساختار و خواص مکانیکی اتصال جوشکاری همزن اصطکاکی ورق نازک آلومینیم 7075-T6

نوع مقاله : علمی و پژوهشی

نویسندگان

• علی مهری ¹
• امیر عبداله زاده ¹
• سینا انتصاری ¹
• حمید اسدی ¹
• جین تائو وانگ ²

¹ دانشگاه تربیت مدرس

² دانشگاه علم و صنعت نانجینگ

10.22067/ma.v30i1.55116

چکیده

در این پژوهش، اتصال­دهی ورق نازک آلومینیم 7075-T6 بوسیله جوشکاری همزن اصطکاکی با موفقیت انجام شد. سرعت حرکت خطی جوشکاری مقدار ثابت 50 میلیمتر بر دقیقه و سرعت چرخشی ابزار 600، 1000 و 1600 دور بر دقیقه انتخاب شدند. با کمک میکروسکوپ الکترونی عبوری و سنجش پراش الکترون برگشتی، مکانیزم تغییرات ریزساختاری فلز جوش تعیین گردید. نتایج نشان داد حین فرآیند جوشکاری همزن اصطکاکی، پدیده­هایی مثل رسوب­گذاری، تبلور مجدد دینامیکی پیوسته، رشد دانه و همچنین انحلال رسوبات در ناحیه همزده جوش اتفاق می افتند که بر خواص مکانیکی اتصال تاثیر بسزایی دارد. همچنین در جوشکاری همزن اصطکاکی ورق نازک آلومینیم، عامل تعیین کننده ریز ساختار نهایی اتصال، کرنش مکانیکی پلاستیک فرآیند بوده و اثر آن بیش از حرارت ورودی جوشکاری می­باشد.

کلیدواژه‌ها

• جوشکاری همزن اصطکاکی
• آلیاژ آلومینیم
• تبلور مجدد
• خواص مکانیکی
• رسوب گذاری

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عنوان مقاله [English]

The Effects of Tool Rotational Speed on the Microstructure and Mechanical Properties of Friction Stir Welded 7075-T6 Aluminum Thin Sheet

نویسندگان [English]

• Ali Mehri ¹
• Amir Abdollahzadeh ¹
• Sina Entesari ¹
• Hamid Assadi ¹
• Jin Tao Wang ²

¹ Tarbiat Modares University

² Nanjing University of Science and Technology, Nanjing, China

چکیده [English]

In the present research, FSW of thin sheets of the 7075-T6 aluminum alloy were investigated. Welding speed was held at 50 mm/min. The tool rotational speeds were 600, 1000 and 1600 rpm. The microstructure was investigated by both transmission electron microscope (TEM) and electron backscattered diffraction scans (EBSD). The results indicated that several phenomena occur instantly during FSW in the stir zone, such as precipitation, continuous dynamic recrystallization (CDRX), grain growth and precipitates dissolution which have a severe effect on the mechanical properties. It could also be concluded that for thin sheet of 7075-T6 aluminum alloy, plastic strain is the dominating factor over heat input of the FSW in determination of the microstructure of the weld zone.
 

کلیدواژه‌ها [English]

• Friction Stir Welding
• Aluminum alloys
• Recrystallization
• Mechanical properties
• Precipitation

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