Mechanical-activation-assisted combustion synthesis of SiC powders with polytetrafluoroethylene as promoter

摘要

Mechanical-activation-assisted combustion synthesis of SiC has been conducted with polytetrafluoroethylene (PTFE) as promoters. The mechanical activation of the Si-C reactants with the addition of NH_4Cl as process controlling agent during the high-energy attrition milling could substantially decrease the content of PTFE promoter, which is needed for inducing the Si-C combustion reaction. Ultra-fine β-SiC powders with spherical particles were synthesized at PTFE content as low as 6 wt.%. The combustion synthesized SiC powders have a narrow particle size distribution in the range of 0.5-1 μm.