Ti3SiC2/UO2 composite pellets with superior high-temperature thermal conductivity

Abstract Ti 3 SiC 2 with a continuous network structure was introduced to UO 2 to improve the thermal conductivity of UO 2 . A dense microstructure with a clean Ti 3 SiC 2 -UO 2 interface was obtained using the spark plasma sintering (SPS) method. Ti 3 SiC 2 exhibited high thermal conductivity at elevated temperature, and a coefficient of thermal expansion (CTE) close to UO 2 . Therefore, the thermal conductivity of Ti 3 SiC 2 /UO 2 was greatly improved compared to that of UO 2 , particularly at high temperature. The enhancing effect of Ti 3 SiC 2 even exceeded those of SiC and BeO above the working temperature of fuel pellets. This improvement in thermal conductivity is of great importance for enhancing the fuel safety under accident conditions.