Journal of the American Ceramic Society, Vol.102, No.8, 4470-4479, 2019
Fabrication of core-shell structured TiC-Fe composite powders by fluidized bed chemical vapor deposition
Fluidized bed chemical vapor deposition (FBCVD) was an effective way of preparing the core-shell structured TiC-Fe composite powders by employing FeCl3 as a precursor. Fully covered TiC-Fe composite powders with the controllable Fe contents were readily achievable. An excellent interfacial bonding was formed between the TiC and the deposited Fe coating. The defluidization caused by the directional growth and self-nucleation-aggregation of the deposited Fe particles was the major barrier to depositing high-Fe-content composite powders. But it could be prevented by controlling the gas partial pressure of precursor and further eliminating the directional growth mode and self-nucleation behavior of Fe atoms. The optimal deposition temperature was 600 degrees C and the partial pressure was about 20 kPa, corresponding to the gasification temperature of 275 degrees C.
Keywords:ceramic-metal systems;chemical vapor deposition;composites;core-shell structures;sinter;sintering