Characterization of γ-U–10wt.%Mo alloy powders obtained by hydride-milling-dehydride process

Abstract Uranium–molybdenum alloy powders are raw material of uranium alloy fuels prepared by powder metallurgic process in nuclear reactor. U–10 wt.%Mo alloy powders were prepared directly by hydride-milling-dehydride process without γ phase to α phase transformation under long time heat treatment, the powders were studied by XRD and SEM. During absorb–desorb hydrogen cycle, the absorbed hydrogen quantity of U–10 wt.%Mo alloy increased with the cycle number increasing, after eight cycles, the absorbed hydrogen quantity reached a stable value, and absorbed hydrogen was saturated in alloy. U–10 wt.%Mo alloy hydride was milled in argon atmosphere, then, alloy hydride were heated to desorb the absorbed hydrogen at 600 °C, after these processes, U–10 wt.%Mo alloy powders were obtained. XRD results show that U–10 wt.%Mo alloy powders was still γ phase, its indicated that during preparation, the alloy was always body centered cubic structure, phase transformation process did not exist. SEM observation showed that the particle shape of U–10 wt.%Mo alloy powders was nonuniform, but particle size was less than 50 μm, some were below 10 μm.