Research Progress on Application of Mo-Re Alloy in Space Nuclear Power

The addition of rhenium (Re) in molybdenum (Mo) can significantly improve the low temperature brittleness of Mo and its processing and welding properties. It can improve the strength of the alloy while maintaining good plasticity. When the content of Re element is about 14%, the elongation of Mo-Re alloy at room temperature is about 40%, and its processability is the best. At the same time, it can maintain a certain solution strengthening effect of Re element. At temperatures below 1 550 K, Mo-Re alloy has good compatibility with UO₂. At temperatures below 1 300 K, Mo-Re alloy has good compatibility with UN. In addition, Mo-Re alloy has good compatibility with alkali metals of Li, Na and K below 1 800 K. Mo-Re alloy has good compatibility with both nuclear fuel and alkali metal coolant. Moreover, Re element is a good spectral shift absorber material, and can effectively reduce the critical accident risk of the reactor. Mo-Re alloy is the best reactor core material for space nuclear power. The research progress of Mo-Re alloy was summarized in this paper and the research results provide reference for the design and research of domestic related space nuclear power.