Abstract
The effect of sinusoidal central gas injection on the in-flight alumina spheroidization process was experimentally clarified by using DC-RF hybrid plasma flow system under a small input power. Spheroidization ratio was evaluated with correlating to frequency and amplitude of sinusoidal central gas injection, DC arc voltage, and also particle size distribution. Spheroidization ratio improves through active mixing of DC-RF hybrid plasma flow with powder. The maximum spheroidization ratio of 99 % for powder collected at z = 120 mm was obtained at f_c = 2 Hz with amplitude of ± 20 %.
