کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1580061 | 1645418 | 2009 | 4 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Hydrogen diffusion in the Laves-phase compound TiCr1.78
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کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
مهندسی مواد
دانش مواد (عمومی)
پیش نمایش صفحه اول مقاله
چکیده انگلیسی
The temperature dependence of the Young's modulus and of the internal friction (IF) has been investigated between 80 and 300 K at acoustical frequencies in the hexagonal (C14) Laves-phase TiCr1.78 charged with hydrogen. In this compound H occupies tetrahedral interstitial sites which are grouped in interlinked hexagons. A mechanical relaxation has been found at around 120 K (f = 5.4 kHz), which appears to be due to tunnelling transitions of delocalized H from one hexagon to the other. The rate of H absorption has been investigated at high temperature (660-1200 K) and the H diffusion coefficient has been derived from the pressure measurement as a function of time. A cumulative Arrhenius plot of IF and absorption diffusion data exhibits a non-exponential behaviour, which is due to a change in the diffusion mechanism from over-barrier hopping at high temperature to phonon-assisted tunnelling at low temperature.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Materials Science and Engineering: A - Volumes 521â522, 15 September 2009, Pages 139-142
Journal: Materials Science and Engineering: A - Volumes 521â522, 15 September 2009, Pages 139-142
نویسندگان
G. Mazzolai, B. Coluzzi, A. Biscarini, F.M. Mazzolai, A. Tuissi, F. Agresti, G. Principi, S. Lo Russo,