کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
10714309 | 1025585 | 2011 | 10 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Thermodynamics of αâ³âβ phase transformation and heat capacity measurements in Ti-15 at% Nb alloy
دانلود مقاله + سفارش ترجمه
دانلود مقاله ISI انگلیسی
رایگان برای ایرانیان
کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
فیزیک و نجوم
فیزیک ماده چگال
پیش نمایش صفحه اول مقاله

چکیده انگلیسی
The phase stability of Ti-15 at% Nb alloy has been studied in the temperature range 466-1258 K using inverse drop calorimetry. In the annealed condition, the alloy consists of orthorhombic αâ³-martensite and bcc β phases. The calorimetry experiments indicated the occurrence of two phase changes upon heating. They are (i) precipitation of hexagonal Ï phase at 582±2 K followed by (ii) αâ³âβ in the temperature domain 836-985±2 K. The enthalpy change due to Ï formation is small; however, the αâ³âβ phase transformation is associated with a measurable enthalpy effect of 57±3 J gâ1. Since αâ³âβ phase change occurs over a temperature interval, the measured enthalpy in the transformation domain derives from two principal contributions, namely, the matrix contribution coming from untransformed αâ³-martensite and β phase mix and another transformational component arising from continuous αâ³âβ phase change. Since the fractional extent of αâ³âβ transformation varies continuously with temperature the transformation enthalpy also exhibits similar temperature dependence. This aspect is modeled using Kolmogorov-Johnson-Mehl-Avrami formalism for treating the diffusional transformation kinetics. Further, the measured enthalpy variation with temperature has been subjected to standard analytical treatment to obtain a comprehensive thermodynamic description of entire αâ³+β region.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Physica B: Condensed Matter - Volume 406, Issue 22, 15 November 2011, Pages 4200-4209
Journal: Physica B: Condensed Matter - Volume 406, Issue 22, 15 November 2011, Pages 4200-4209
نویسندگان
A. Josephine Prabha, S. Raju, B. Jeyaganesh, Arun Kumar Rai, Madhusmita Behera, M. Vijayalakshmi, G. Paneerselvam, I. Johnson,