نویسندگان

دانشگاه صنعتی مالک اشتر، دانشکده مهندسی مواد، اصفهان، ایران

چکیده

در این تحقیق کامپوزیت­ Ti-48Al/Ti2AlC و Ti-48Al(8Nb)/Ti2AlC به روش آلیاژسازی مکانیکی و پرس گرم سنتز شد. ابتدا مخلوط پودری عناصر به مدت 75 ساعت تحت عملیات آلیاژسازی مکانیکی قرار گرفتند و سپس به منظور تولید قطعات بالک، عملیات پرس گرم در دمای ℃ 1000 به مدت 1 ساعت بر روی پودرها انجام پذیرفت. آزمون اکسیداسیون در دمای ℃ 1000 در هوا به منظور مقایسه رفتار اکسیداسیون نمونه ها انجام گرفت. نمونه ­های سنتز شده و اکسیداسیون توسط میکروسکوپ الکترونی روبشی، طیف ­سنج انرژی اشعه ایکس و دستگاه پراش سنج پرتو ایکس مورد مطالعه قرار گرفتند. مطابق با نتایج الگوی پراش پرتوی ایکس، فازهای تشکیل شده برای هر دو نمونه تولیدی، گاما - آلومیناید تیتانیم و Ti2AlC شناسایی شد و هیچ فازی بر پایه نیوبیوم تشکیل نشد. نتایج آزمون اکسیداسیون نشان داد که مقاومت به اکسیداسیون نمونه­ آلیاژی با افزودن نیوبیوم بهبود یافته است. رشد اکسید تیتانیم به دلیل جایگزین شدن اتم ­های نیوبیوم با اتم ­های تیتانیم کاهش یافت. همچنین ترکیب شیمیایی پوسته اکسیدی با افزودن نیوبیوم در نمونه تغییر کرد که دلیل آن پایدار شدن لایه نیتریدی می‌باشد.

کلیدواژه‌ها

عنوان مقاله [English]

Investigation of Niobium Addition Effect on Oxidation Resistance of Ti-48Al/Ti2AlC Composite

نویسندگان [English]

  • Hadi Karimi
  • Ali Ghasemi
  • Morteza Hadi
  • Mohsen Sadeghi Mohammadi

Malek-Ashtar University of Technology, Department of Materials Engineering Shahin Shahr, Isfahan, Iran

چکیده [English]

In this research, the Ti-48Al/Ti2AlC and Ti-48Al(8Nb)/Ti2AlC composites were synthesized by means of
mechanical alloying and hot pressing. Firstly, the mixture of elemental powders were subjected to mechanical alloying
for 75 h and then to produce bulk samples, the milled powders were hot pressed for 1 h at 1000℃. Oxidation tests were
carried out in air at 1000 ℃ to compare the oxidation behavior of samples. Synthesized and oxidized samples were
studied by scanning electron microscopy, energy dispersive spectroscopy (EDS) and X-ray diffractometry (XRD).
According to X-ray diffraction patterns, the presence of γ-TiAl and Ti2AlC phases were detected for produced samples
and no phases on the base of Nb were formed. The results showed that the oxidation resistance of alloy was improved
by niobium addition. The growth of rutile was suppressed by substitution Nb for Ti in TiO2 lattice. Furthermore, scale
composition changed with addition of niobium that was related to the stabilization of nitride layer. 

کلیدواژه‌ها [English]

  • Ti-48Al/Ti2AlC composite
  • Mechanical alloying
  • Hot pressing
  • Oxidation
  • Niobium
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