The microstructure of the fuel pellet plays an essential role in fission gas buildup and release and is critical for the safe and continued operation of nuclear power stations. Structural analysis of uranium dioxide (UO₂)–molybdenum (Mo) composite fuel pellets prepared at a range of sintering temperatures from 1300 to 1800 °C was performed. Mo micro and nanoparticles were used in making the composite pellets. A systematic investigation into the influence of processing parameters during Spark Plasma Sintering (SPS) of the pellets on the microstructure, texture, grain size, and grain boundary characters of UO₂-Mo is presented. UO₂-Mo composite show significant differences in the fraction of general boundaries and also special/coincident site lattice (CSL) boundaries. EBSD orientation maps demonstrated that <111> texturing was observed in the pellets fabricated at 1500 °C. The experimental investigations suggest that UO₂-Mo composite pellets have favorable microstructural features compared to the UO₂ pellet.

燃料芯块的微观结构在裂变气体的积聚和释放中起着至关重要的作用，对核电站的安全和持续运行至关重要。对在 1300 至 1800 °C 的烧结温度范围内制备的二氧化铀 (UO ₂ )-钼 (Mo) 复合燃料芯块进行了结构分析。钼微粒和纳米颗粒用于制造复合颗粒。系统研究了球团火花等离子烧结 (SPS) 过程中的加工参数对 UO ₂ -Mo的微观结构、织构、晶粒尺寸和晶界特征的影响。铀₂-Mo 复合材料在一般边界和特殊/重合位点晶格 (CSL) 边界的分数上显示出显着差异。EBSD 取向图表明在 1500 °C 下制造的颗粒中观察到 <111> 纹理。实验研究表明，与UO ₂球团相比，UO ₂ -Mo 复合球团具有良好的微观结构特征。