کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1601502 | 1005201 | 2008 | 12 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Thermal stability of Ti-44Al-8Nb-1B alloy
دانلود مقاله + سفارش ترجمه
دانلود مقاله ISI انگلیسی
رایگان برای ایرانیان
کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
مهندسی مواد
فلزات و آلیاژها
پیش نمایش صفحه اول مقاله
چکیده انگلیسی
A fully lamellar γ-TiAl alloy Ti-44Al-8Nb-1B was exposed to the temperature of 700 °C in air for up to 5000 h. The changes in microstructure were investigated using scanning and transmission electron microscopies. The fine-grained lamellar microstructure produced by ingot-casting and hot-isostatic pressing is found to be thermodynamically unstable. Metastable α2 lamellae readily decompose and three types of phase transformation occur during the exposure. The first is α2 â γ, occurring with the parallel decomposition of coarse α2 laths. The second is α2 â B2(Ï), occurring along single α2 laths. The third is α2 + γ â B2(Ï), occurring on decomposing α2 + γ lamellae packets. The B2(Ï) formed is found to be not very different from their parent phase(s) in composition. A widespread precipitation of B2(Ï) therefore proceeds, causing segregation both at colony boundaries and inside lamellar colonies. The volume fraction of B2(Ï) is almost doubled: from 3% in the as-cast condition to 5.8% after 5000-h exposure.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Intermetallics - Volume 16, Issue 2, February 2008, Pages 156-167
Journal: Intermetallics - Volume 16, Issue 2, February 2008, Pages 156-167
نویسندگان
Z.W. Huang, D.G. Zhu,