Synthesis of mono-phase, hexagonal plate-like Al<sub>4</sub>SiC<sub>4</sub> powder via a carbothermal reduction process

Abstract

Mono-phase and hexagonal plate-like Al 4 SiC 4 powders were successfully synthesized using a mixture of Al(OH) 3 , SiO 2 and phenolic resin via the carbothermal reduction process. Two-step reaction was compartmentally observed during calcination; the carbothermal reduction of SiO 2 between 1300 and 1600°C and that of Al 2 O 3 above 1500°C. X-ray diffraction data indicated the orientation of the compacted powders along c-axis due to the stacking of plate-like Al 4 SiC 4 powders. Microscopic observation showed that the synthesized powders were mainly hexagonal platelets. The main synthetic mechanism of the ternary carbide powder during the carbothermal reduction process was gas-solid reaction. Possible reaction mechanisms which are responsible for the synthesis of Al 4 SiC 4 by the carbothermal reduction process are discussed.