Hot-corrosion behavior of Ti3SiC2 in a eutectic mixture of LiCl–KCl salts in air

Abstract

High-corrosion-resistant materials are required for the pyrochemical reprocessing of spent fuels. Towards this end, the hot-corrosion behavior of polycrystalline Ti₃SiC₂ in a eutectic mixture of LiCl–KCl melts was investigated for 100 h at 550 °C, 650 °C, and 750 °C in air. The results indicate that Ti₃SiC₂ exhibits excellent corrosion resistance in LiCl–KCl at 550 °C. However, it undergoes hot-corrosion at 650 °C and 750 °C, with the mass gains per unit area being approximately 0.4 and 1.6 mg cm⁻², respectively. The main corrosion products at 650 °C and 750 °C were found to be TiO₂ and Li₂TiO₃, respectively. It was surmised that Ti₃SiC₂ exhibits good corrosion resistance at 550 °C and is partly corrosion resistant because the oxide products form a stable protective film on the specimen surface at 650 °C and 750 °C. Finally, the microstructures and phase compositions of the corroded samples were investigated using scanning electron microscopy/energy-dispersive X-ray spectroscopy and X-ray diffraction analysis.