Investigation of interdiffusion behavior in the Mo-Zr binary system via diffusion couple studies
Abbreviated Journal Title
Int. J. Refract. Met. Hard Mat.
Interdiffusion; Interdiffusion coefficients; Diffusion couples; Molybdenum; Zirconium; CR; Materials Science, Multidisciplinary; Metallurgy & Metallurgical; Engineering
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.
International Journal of Refractory Metals & Hard Materials
"Investigation of interdiffusion behavior in the Mo-Zr binary system via diffusion couple studies" (2014). Faculty Bibliography 2010s. 5978.