Research On Cold Drawing And Mid-Annealing Techniques Of AZ31 Magnesium Alloy Superfine-Wire

Because of the poor plasticity of magnesium alloy decided by its crystal lattice at low temperature, correlative studies are very few. And the hard-shaped capability makes investigations of its super-wires fewer. But the applications of magnesium wires are very important in national products. So study of cold drawing and mid-annealing techniques was performed on AZ31magnesium alloy wires in this paper, to enlarge its application and exploit its new technique.On the basis of analysis of impact factors on accumulative cold deformation, cold drawing technique fromΦ2.0 mm toΦ0.12mm was established. Also by studies of annealing techniques on different cold deformation and different diameter wires, mid-annealing to again fined-grains was made out.By means of optical microscope (OM), the evolvement of micro-structures of cold drawing and annealing was observed. The tensile deformation behavior and micro-rigidity test of cold-drawing and annealing wires at ambient temperature were analyzed. The fracture was also observed by scanning electronic microscopy (SEM).The study showed, critical deformation degree of AZ31 magnesium alloys was around 10%; with decrease of diameter and grain size of wires, the accumulative cold deformation between two mid-annealing was increased; and recrystallized temperature was down as the cold deformation was increased, but no less than 473K; micro-hardness and tensile strength were enhanced with decrease of grain size, and reached 73.3HV, 467.4MPa(UTS), but lowered forΦ0.12mm wire.