A solid-to-solid, U-7wt.%Mo vs. Mg diffusion couple was assembled and annealed at 550°C for 96 hours. Themicrostructurein the interdiffusion zone and the development of concentration profiles were examined via scanning electron microscopy, transmission electron microscopy (TEM) and X-ray energy dispersive spectroscopy. A TEM specimen was prepared at the interface between U-7wt.%Mo andMgusing focused ion beam in-situ lift-out. The U-7wt.%Mo alloy was bonded well tothe Mg at the atomic scale, without any evidence of oxidation, cracks or pores.Despite the good bonding, very little or negligible interdiffusion was observed.This is consistent with the expectation based on negligible solubilities according to the equilibrium phase diagrams. Along with other desirableproperties, Mgis a potential inert matrix or barrier materialfor U-Mo fuel alloy systembeing developed forthe Reduced Enrichment for Research and Test Reactor (RERTR) program.
In-situ Creep Testing Capability Development for Advanced Test Reactor