Effects of different processes and pulse current on microstructure and mechanical properties of AZ31 magnesium alloy plate rolled in multiple passes were investigated by OM

SEM and tensile testing machine. The results show that recrystallization of AZ31 alloy can be achieved by power frequency and instantaneous pulse current

which can replace recrystallization annealing process to adjust tensile strength and elongation of the alloy. In the range of 50～200 A/mm~2

as the current density increases

the number of recrystallized grains in the alloy is increased gradually. Tensile strength of the alloy is increased at first and then decreased

where the maxium value can be obtained at 100 A/mm~2

and elongation of the alloy is increased gradually. When the current processing time is 120～240 ms or the number of current cycles is 1～4 cycles

as the current processing time or the number of current cycles increases

the number of recrystallized grains in the alloy is increased gradually

resulting in decrease of tensile strength and increase of elongation.