Previous studies have established that Th-U alloys up to 20 wt%U have good irradiation stability. To retain or enhance the irradiation stability of Th-U alloys with increase in uranium content, uranium should be stabilised as isotropic γ-U. Molybdenum is one of the most potent stabilizers of γ-U. Although U-Mo system is well studied, scant availability of open literature related to Th-U-Mo system indicates, need for planned studies. In the present study, effect of molybdenum addition on the microstructural evolution and stability of γ-U phase in some selected compositions of Th-30U alloy has been investigated. A pseudo binary phase diagram of Th-Mo at 30 wt%U has been constructed by CALPHAD approach using respective binary interaction parameters. The origin of as cast microstructure is explained with the help of assessed phase diagram. Three different compositions of Th-U-Mo alloy with varying molybdenum content have been evaluated for their potential application as nuclear fuel.

先前的研究已经确定，高达20 wt％U的Th-U合金具有良好的辐照稳定性。为了保持或增强随铀含量增加的Th-U合金的辐照稳定性，应将铀稳定为各向同性的γ-U。钼是γ-U最有效的稳定剂之一。尽管对U-Mo系统进行了很好的研究，但与Th-U-Mo系统有关的开放文献很少，表明需要进行有计划的研究。在本研究中，已经研究了钼对Th-30U合金某些选定成分中γ-U相的组织演变和稳定性的影响。通过CALPHAD方法，使用各自的二元相互作用参数构建了Th-Mo在30 wt％U处的伪二元相图。铸态显微组织的起源在评估相图的帮助下进行了解释。