Influence of pulsed magneto oscillation treatment on eutectic nucleation kinetics of hypereutectic Al-Si alloys

The eutectic nucleation kinetics of Al-25%Si alloys was investigated under pulsed magneto oscillation treatment using differential scanning calorimeter. In the eutectic melting of untreated and treated Al-25%Si alloys, the onset temperature remains roughly constant, and both the peak and end temperatures increase with increased heating rate. In the eutectic solidification, the onset temperature of two alloys remains roughly constant, and both the peak and end temperatures decrease with increased cooling rate. The activation energy and nucleation energy of the treated Al-25%Si alloy decrease, but the eutectic nucleation rate increases. Based on PMO treatment refinement mechanism and eutectic structure analysis, the eutectic structure of Al-25%Si alloys is refined with the decreased size and increased area fraction of primary silicon.