تأثیر نرخ سرمایش و مقدار مس بر ریزساختار آلیاژZn–27%Al تحت ریخته‌گری تبریدی

نوع مقاله : علمی و پژوهشی

نویسندگان

• رحیم اعرابی جشوقانی
• حمید پیرنجم الدین
• حسن قهوه چیان
• حمیدرضا شاهوردی

تربیت مدرس

10.22067/ma.v28i2.35765

چکیده

در این پژوهش تأثیر نرخ سرمایش و مقدار مس بر ریزساختار آلیاژ Zn–27%Al با استفاده از ریخته‌گری تبریدی در قالب ماسه‌ای بررسی شد. بررسی‌های ریزساختاری نشان داد که با کاهش نرخ سرمایش، فاصله بازوهای دندریتی و درصد فازهای بین دندریتی افزایش یافت. همچنین افزودن مس به میزان 1 درصد وزنی تغییر قابل توجهی در ساختار ایجاد نکرد در حالیکه افزودن مقادیر 2 و 4 درصد وزنی منجر به تشکیل رسوب -CuZn4Ԑ در نواحی بین دندریتی شد. علاوه براین با کاهش نرخ سرمایش، مورفولوژی رسوبات Ԑ از حالت نیمه ورقه‌ای به کروی شکل تغییر کرد.

کلیدواژه‌ها

• ریخته‌گری تبریدی
• آلیاژ ZA27
• ریزساختار
• نرخ سرمایش

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عنوان مقاله [English]

Influence of Cooling Rate and Copper Content on the Microstructure of Zn–27%Al Alloy under End-chill Casting

نویسندگان [English]

• Rahim Arabi Jeshvaghani
• Hamid Pirnajmoddin
• Hassan Ghahvechian
• Hamid Reza Shahverdi

Tarbiat Modares University

چکیده [English]

In this research, the effect of cooling rate and copper content on the microstructure of Zn–27%Al alloy was investigated using chilled casting in a sand mould. Microstructural examination showed that with decreasing cooling rate, dendrite arm spacing and the percentage of interdendritic phases increased. Moreover, addition of copper up to 1 wt. % did not lead to significant change in microstructure, while addition of 2, and 4 wt% copper led to the formation of -CuZn4 phase in the interdendritic regions. In addition, with decreasing cooling rate, the morphology of - precipitates varied from semi-plate-like to spherical.

کلیدواژه‌ها [English]

• End-Chill Casting
• ZA27 Alloy
• Microstructure
• Cooling rate

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