Industrial pure Al was treated by a self-developed low voltage and low frequency pulsed apparatus.The long columnar crystals which grows up from the outside to the inside in macrostructure with melt pulsed current treatment were broken off

and the peripheral coarse dendrite exhibits fine and short trend.With the increase of the pulse voltage

the area of equiaxed crystal is increased with the decrease of equiaxed crystal grain’s size to be stable.With increasing in duty

equiaxed area and grain size are increased firstly and then decreased

where with 60% duty

melting treating is desirable.Compared with those of the pure aluminum without pulsed treatment

the hardness

tensile strength

yield strength

elongation of pure aluminum with pulsed treatment are increased by 10%

13.9%

9.3%and 10.4%

respectively.The experimental results reveal that the super-cooled degree of liquid Al during solidification process is affected by pulsed current

leading to the fluctuation of grain refinement.This role is attributed to combined effect of various parameters

however it is not belong linear relationship.