Effect Of Electric Pulse On Solidification Behavior And Mechanism Of Al-5%Cu Alloy

Electric pulse modification (EPM) is a novel technique for the refinement of alloy solidification structure. In the past few years, which become grandully current issue. By using electromagnetism theory combined with the electric pulse modification mechanism, the two critical values of pulse voltage were calculated when the crystal rain and the chill layer were formed during solidification. The equivalent current and its influencing factors were model-based investigated and the solidification behavior was analyzed correspondingly. The model exhibits that the time domain of EPM-induced grain refinement is between the occurrence of crystal rain and the formation of chill layer. Furthermore, the proposed model is validated by the solidification structure changes of Al-5%Cu alloy under this circumstance.The influence of Al-5%Cu alloy solidified structure was investigated by cooling curve and DSC's contrast. results show that the cooling curve was obtain significant increase by electric pulse discharging. it is treated with different Pulse voltage, and establish the cooling curve, resulted show that the effect of 500V has a maximal supercooling on the curve. it is treated with different Pulse frequency, the effect of 3Hz has a maximal supercooling on the curve. The nucleation rate has a preferable coincidence relation with the change of the cooling curve, the optimum of grain refinement is obtained by 500V or 3Hz, and the lower or higher pulse voltage is disadvantageous. meanwhile the temperature of Phase transformation was reduced with EPM.In addition, the ODF cross section diagram(ΔФ=45o) of Al-5%Cu as-cast texture with different Pulse voltage is shown, a typical type of {112}<110> also will be weaken with increasing pulse voltage; When the pulse voltage is 500V, a typical type of {112}<110> texture disappear eventually; the maximum value of orientation density is 19.372 without EPM. By contrast, when the pulse voltage is 300V, the maximum value of orientation density is 4.858, when the pulse voltage increase to 500V, the maximum value of orientation density is only 2.758. the grain orientation was obtain significant change with EPM during solidified process.Therefore, it is indicated that EPM can establish the foundation for the production application.