Investigation of interdiffusion behavior in the Mo-Zr binary system via diffusion couple studies

    Authors

    A. P. Y. Puente; J. Dickson; D. D. Keiser;Y. H. Sohn

    Comments

    Authors: contact us about adding a copy of your work at STARS@ucf.edu

    Abbreviated Journal Title

    Int. J. Refract. Met. Hard Mat.

    Keywords

    Interdiffusion; Interdiffusion coefficients; Diffusion couples; Molybdenum; Zirconium; CR; Materials Science, Multidisciplinary; Metallurgy & Metallurgical; Engineering

    Abstract

    Zirconium has recently garnered attention for use as a diffusion barrier between U-Mo metallic nuclear fuels and Al alloy cladding. In order to gain a fundamental understanding of the diffusional interactions, the interdiffusion behavior in the binary Mo-Zr system was investigated via solid-to-solid diffusion couples annealed in the temperature range of 750 to 1050 degrees C. A combination of scanning electron microscopy, X-ray energy dispersive spectroscopy, and electron probe microanalysis were used to examine the microstructure and concentration profiles across the interdiffusion zone. A large beta-Zr (cI2) solid solution layer and a thin (similar to 1-2 mu m) layer of Mo2Zr (cF24) developed in all couples. Parabolic growth constants and concentration dependent interdiffusion coefficients were calculated for the Mo2Zr and Zr solid solution phases, respectively. The pre-exponential factor and activation energy for growth of the Mo2Zr phase were determined to be approximately 6.5 x 10(-15) m(2)/s and 90 kJ/mol, respectively. The interdiffusion coefficient in beta-Zr solid solution decreased with an increase in Mo concentration. Both the pre-exponential factors (2 x 10(-8) m(2)/s at 2 at.% Mo to near 5 x 10(-8) m(2)/s at 9 at.% Mo) and activation energies (140 kJ/mol at 2 at.% Mo to approximately 155 kJ/mol at 9 at.% Mo) of interdiffusion coefficients were determined to increase with an increase in Mo concentration. (C) 2014 Elsevier Ltd. All rights reserved.

    Journal Title

    International Journal of Refractory Metals & Hard Materials

    Volume

    43

    Publication Date

    1-1-2014

    Document Type

    Article

    Language

    English

    First Page

    317

    Last Page

    321

    WOS Identifier

    WOS:000333789700048

    ISSN

    0263-4368

    Share

    COinS