In-situ preparation and characterization of silicon carbide ultrafine powder by molten salt method

In-situ preparation of ultrafine silicon carbide (SiC) powders had been successfully achieved in the Potassium Chloride (KCl) and Sodium Chloride (NaCl) molten salt system. The results showed that the optimized preparation conditions for SiC in the air were: a reaction temperature of 1400℃, a carbon-silicon ratio of 1:7, and a molten salt ratio of 1:4. The optimal temperature for synthesizing SiC in a vacuum was 1300℃. Notably, SiC synthesized at 1300℃ in a vacuum had a smaller particle size and a more uniform distribution compared to SiC prepared in air. This study successfully prepared ultrafine SiC powders using the molten salt method and underscored the significance of vacuum conditions in optimizing SiC performance and particle size distribution.