The influence of low-voltage electric current pulse （LVECP） on solidified structure of Al-4.5Cu alloy was studied

and the effects of cooling rate

pulse voltage and treating time on grain size of the alloy were investigated. Experimental results indicate that the solidified structure of Al-4.5Cu alloy can be remarkably refined

where primary α-Mg phase is converted from developed dendrites into uniformly fine rosette grain after LVECP treatment. With cooling rate and pulse voltage increase

the grain size of Al-4.5Cu can be reduced gradually. However

with the pulse voltage increasing to 400V

grain size in the Al-4.5Cu alloy can be increased slightly. As treating time increasing from 0 to 10 min

the grain size can be decreased greatly

while the treating time is more than 10 min

grain size in Al-4.5 Cu alloy can be somewhat increased with increasing in treating time.