Effect of microstructure on mechanical properties of a depleted uranium-2 wt.% molybdenum alloy

The mechanical properties measured in dry air of two microstructural variations of a depleted uranium-2 wt.% molybdenum alloy after exposure to salt-ladened moist air are reported. The structures examined were an α+delta pseudo-lamellar structure obtained by over-aging αsub(b)' and an α + γ structure which was obtained by quenching from the two-phase field. The latter structure reportedly has good elongation in both dry and moist air whereas the former structure reportedly has good elongation in dry air only. Results showed that neither microstructure had elongation greater than 6.7% after exposure to the salt-ladened moist air environment. The low ductility is thought to be caused by either hydrogen embrittlement or the slow quench rate because of increasing section thickness during heat treating. (Auth.)