Preparation of coated Li2TiO3 and Li4SiO4 pebbles by fluidized bed chemical vapor deposition for advanced tritium breeders

Abstract

• Coated breeders were proposed to address safety hazard. • Protective coatings were successfully fabricated by FBCVD for the first time. • Deposition and interface reaction behaviors were revealed. Lithium-based ceramic tritium breeders would attack the blanket structural materials and produce brittle corrosion layers, causing potential safety hazard. Herein, coated breeders were proposed as advanced tritium breeders to address the issue. Carbon (C), titanium nitride (TiN) and titanium carbide (TiC) were investigated as inert protective shells because they show excellent stability and chemical compatibility with Li 2 TiO 3 and Li 4 SiO 4 . Moreover, for the first time, the C and TiN coated Li 2 TiO 3 and Li 4 SiO 4 pebbles were successfully fabricated by fluidized bed chemical vapor deposition (FBCVD) process, which would significantly decrease the brittle corrosion layers and increase the safety. The deposition behavior and interface reactions were systemically investigated.