Through the introduction of electric current pulse to casting roller, the effect of different electric current pulses on casting structure of Al-Mg aluminum alloy were investigated. The control results show that the structure of alloy is changed apparently when the different current pulses are discharged during the casting. The microstructure of alloy is refined apparently under suitable pulse current strength. Compared to un-treated sample,the phenomenon of composition segregation and internal diversity of microstructure are reduced obviously. The microstructure is nearly spherical particle and the component distribution is more uniform with 5.5×106A·m-2 electric current pulse. But segregation on grain boundary is still existed.
|