کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1637424 1516990 2012 8 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Banding structure formation during directional solidification of Pb-Bi peritectic alloys
موضوعات مرتبط
مهندسی و علوم پایه مهندسی مواد فلزات و آلیاژها
پیش نمایش صفحه اول مقاله
Banding structure formation during directional solidification of Pb-Bi peritectic alloys
چکیده انگلیسی
Directional solidification experiments on Pb-Bi peritectic alloys were carried out at very low growth rate (v=0.5 μm/s) and high temperature gradient (G=35 K/mm) in an improved Bridgman furnace. The banding structures were observed in both hypoperitectic and hyperperitectic compositions (Pb-xBi, x=26%, 28%, 30% and 34%). Tree-like primary α phase in the center of the sample surrounded by the peritectic β phase matrix was also observed, resulting from the melt convection. The banding microstructure, however, is found to be transient after the tree-like structure and only the peritectic phase forms after a few bands. Composition variations in the banding structure are measured to determine the nucleation undercooling for both α and β phases. In a finite length sample, convection is shown to lead only to the transient formation of bands. In this transient banding regime, only a few bands with a variable width are formed, and this transient banding process can occur over a wide range of compositions inside the two-phase peritectic region.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Transactions of Nonferrous Metals Society of China - Volume 22, Issue 9, September 2012, Pages 2131-2138
نویسندگان
, , , ,