Chunlong Guan, Xiaoxu Guo, Ye Tian, Shun Wang, Fengchun Wei, Zhiwei Zhao, Zhengxin Li
March 16, 2020
Al 4 SiC 4 powder was successfully synthesised at a temperature 150 °C lower than before: the use of a microwave hybrid heating method required only 3 % of the heating time compared to conventional methods. The effects of composition and processing parameters, such as temperature and dwell time on the formation process of Al 4 SiC 4 were investigated. The results indicated that with the excess Al from 0 to 5 at.% in the composition, the amount of Al 4 SiC 4 phase in the samples processed at 1 200 °C increased together with the decreasing amount of Al 4 C 3 phase. Further increases in the content of Al above 5 at.% resulted in the decrease of the Al 4 SiC 4 phase content. For a fixed composition of Al : SiC : C of 4.05 : 1 : 3, Al 4 SiC 4 formed as a major phase together with the decrease of SiC, C, and Al 4 C 3 phases at temperatures varying from 1 000 °C to 1 500 °C for 6 min. When the dwell time was extended to 15 min at 1 500 °C, a high-purity Al 4 SiC 4 phase with a tiny amount of impurities could be synthesised. The as-obtained powder was mainly composed of hexagonal plate-shaped particles with a mean diameter of approximately 1 μm.