Liquid structure of aluminum binary alloys characterized by electrical parameters under electromagnetic field

Abstract

The electrical parameters of aluminum binary alloys (Al–Fe and Al–Si alloys) have been investigated in the presence of alternating current (AC) and direct current (DC) electromagnetic fields. The results show that both thermoelectric power and electrical resistivity of Al–Fe alloys increase in the AC/DC electromagnetic field, which indicates that the liquid structure is changed by the electromagnetic treatment. Study on Al–Fe alloys with different Fe content reveals that Al-1.99wt.% Fe alloy shows the sharp increase of transient variation ΔS (S: thermoelectric power) and inflection of residual variation ΔS 0 at near eutectic composition in AC electromagnetic field, which is comparable with the electrical resistivity in DC electromagnetic field. In addition, the effects of electromagnetic parameters (setting current, frequency and duty cycle) on voltage/current waveform of power system and thermoelectric power have been further studied. After comparing the results of voltage and current waveforms, it shows that the output current can be regarded as a better evaluation index to the effects of electromagnetic parameters on the thermoelectric power. This quantitative method can clearly analyze the effects of electromagnetic parameters on the liquid structure, which is characterized by the thermoelectric power.