کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1601856 1005219 2008 8 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Experimental reinvestigation of the Co-Nb phase diagram
موضوعات مرتبط
مهندسی و علوم پایه مهندسی مواد فلزات و آلیاژها
پیش نمایش صفحه اول مقاله
Experimental reinvestigation of the Co-Nb phase diagram
چکیده انگلیسی
The phase diagram of the binary Co-Nb system was redetermined in the whole range of compositions by differential thermal analysis (DTA), electron-probe micro analysis (EPMA), powder X-ray diffraction (XRD), and metallography. Equilibrated alloys of more than 30 different compositions and a series of diffusion couples were used in order to establish the invariant reactions in the system and the homogeneity ranges of all phases. A special feature of the Co-Nb system is the occurrence of three different types of the Laves phase NbCo2, which are a cubic variant (C15) and two different hexagonal variants (C14 and C36). The existence of these three types of the Laves phase was confirmed and their homogeneity ranges were established for the first time. The two hexagonal Laves phase variants are stable only at high temperatures and strongly off-stoichiometric compositions. Two more intermetallic compounds exist in the system: The monoclinic phase Nb2Co7 forms by a peritectoid reaction and has a very small homogeneity range, whereas the μ phase Nb6Co7 in the central part of the system melts congruently and is stable within a broad homogeneity range.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Intermetallics - Volume 16, Issue 6, June 2008, Pages 785-792
نویسندگان
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