کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
7992444 | 1516146 | 2018 | 8 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
On Nb silicide based alloys: Part II
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موضوعات مرتبط
مهندسی و علوم پایه
مهندسی مواد
فلزات و آلیاژها
پیش نمایش صفحه اول مقاله
چکیده انگلیسی
The paper examined alloying behaviour in cast and heat treated Nb-silicide based alloys where alloying additions were transition metals (Cr, Hf, Mo, Ta, Ti, W), and simple metal or metalloid elements (Al, B, Ge, Sn). The microstructures of the alloys consisted of bcc Nbss solid solution (which could be of three types, namely normal, Ti rich and with no Si) and intermetallic(s). The study used the parameters entropy (ÎSmix) and enthalpy (ÎHmix) of mixing, atomic size difference (δ), electronegativity difference (ÎÏ), valence electron concentration (VEC), Ωâ¯=â¯Tm ÎSmix/| ÎHmix | and the ratio sd/sp of sd over sp electronic configuration elements. The values of the parameters were in the ranges - 44.8 < ÎHmixâ¯<â¯- 32.7â¯kJ/mol, 8.3 < ÎSmix < 14.7â¯J/molK, 4.4â¯<â¯VEC <4.9, 8.1 < δâ¯<â¯14.3, 0.12 < ÎÏ < 0.24, 0.57 < Ωâ¯<â¯0.95 and 2.12â¯<â¯sd/spâ¯<â¯4.03. Plots of ÎÏ versus δ and ÎÏ versus ÎHmix separated the alloys in three groups according to alloying additions. In these plots the B containing alloys formed their own group. The data for Nb solid solutions from Part I (J Alloys Compd. 708 (2017) 961-971) was used to compare the parameters of the alloys and solid solutions. Plots of ÎÏ versus ÎHmix and ÎÏ versus Ω separated the alloys and their bcc Nb solid solutions according to whether they contained B or not. The parameters ÎHmix, ÎSmix, δ and ÎÏ of some of the Nb-silicide based alloys were in the ranges reported for bcc solid solution + intermetallic(s) high entropy alloys. The values of the parameters ÎHmix, ÎSmix, VEC, δ and ÎÏ were in better agreement with those reported for amorphous alloys.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Alloys and Compounds - Volume 748, 5 June 2018, Pages 569-576
Journal: Journal of Alloys and Compounds - Volume 748, 5 June 2018, Pages 569-576
نویسندگان
P. Tsakiropoulos,