Title

Interdiffusion Between Zr Diffusion Barrier And U-Mo Alloy

Keywords

Diffusion barrier; Diffusion couples; Interdiffusion; Metallic alloys; Multicomponent diffusion; Phase equilibria

Abstract

U-Mo alloys are being developed as low-enrichment uranium fuels under the Reduced Enrichment for Research and Test Reactor (RERTR) program. Significant reactions have been observed between U-Mo fuels and Al or Al alloy matrix. Refractory metal Zr has been proposed as barrier material to reduce the interactions. In order to investigate the compatibility and barrier effects between U-Mo alloy and Zr, solid-to-solid U-10wt.%Mo versus Zr diffusion couples were assembled and annealed at 600, 700, 800, 900, and 1000 °C for various times. The microstructures and concentration profiles due to interdiffusion and reactions were examined via scanning electron microscopy and electron probe microanalysis, respectively. Intermetallic phase Mo2Zr was found at the interface, and its population increased when annealing temperature decreased. Diffusion paths were also plotted on the U-Mo-Zr ternary phase diagrams with good consistency. The growth rate of interdiffusion zone between U-10wt.%Mo and Zr was also calculated under the assumption of parabolic diffusion and was determined to be about 103 times lower than the growth rate of diffusional interaction layer found in diffusion couples U-10wt.%Mo versus Al or Al-Si alloy. Other desirable physical properties of Zr as barrier material, such as neutron adsorption rate, melting point, and thermal conductivity, are presented as supplementary information to demonstrate the great potential of Zr as the diffusion barrier for U-Mo fuel systems in RERTR. © ASM International.

Publication Date

12-1-2012

Publication Title

Journal of Phase Equilibria and Diffusion

Volume

33

Issue

6

Number of Pages

443-449

Document Type

Article

Personal Identifier

scopus

DOI Link

https://doi.org/10.1007/s11669-012-0106-0

Socpus ID

84870981844 (Scopus)

Source API URL

https://api.elsevier.com/content/abstract/scopus_id/84870981844

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