Phase pure HfB 2 SiC powders were efficiently synthesized via microwave/molten salt assisted boro/ carbothermal reduction (MMS-BCTR) method by using HfO 2 , SiO 2 , activated carbon and B 4 C powders as raw materials, and NaClKCl as a molten salt medium. The effects of mass ratio of salt to reactant (m s /m r ), holding period, reaction temperature and B 4 C content on the phase composition and microstructure of the synthesized HfB 2 SiC powders were investigated. The results showed that the

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... imal molar ratio of HfO 2 / SiO 2 /B 4 C/C was 3.0:1.0:3.2:4.0, m s /m r was 2.0, and reaction temperature and holding period were respectively 1250°C and 20 min. Rod-shaped HfB 2 and irregular SiC particles were uniformly distributed in the products, the former with a length of 0.5¯m and a diameter of 300 nm exhibited a single-crystal structure with a preferred growth along the [100] direction, while the latter had a particle size of about 300 nm.