Investigation of the Fragmentation Mechanism of Alumina Powders Induced by Nanosecond‐Pulsed Discharge Plasma

This study investigates the fragmentation mechanism of alumina powders treated by nanosecond‐pulsed SDBD plasma. Experimental observations revealed a directional powder migration driven by Fast Gas Heating (FGH)‐induced aerodynamic flow. In‐situ fluorescence thermometry recorded a heating rate of only 1.3 K/s, effectively ruling out thermal shock. Instead, microstructural analysis—showing fatigue striations and lattice plastic deformation—confirms that fragmentation results from mechanical fatigue fracture induced by high‐frequency aerodynamic shock waves. These findings elucidate the non‐thermal physical nature of plasma‐powder interactions, providing a theoretical basis for precise particle size control in brittle material processing.