ACHIEVING ULTRAFINE GRAIN SIZE IN <font>Mg</font>-<font>Al</font>-<font>Zn</font> ALLOY BY COLD DRAWING

Ultrafine-grain size of ~1&#181;m was achieved in an AZ31B Mg alloy wires with high strength prepared by cold drawing and subsequent annealing in the present study. Effects of cold-drawn area reduction (CAR) on strain hardening, recrystallized grain refinement and annealing temperature were investigated. The results showed that the maximum cold area reduction as high as 65.1% could be reached at room temperature, which resulted in the notable strain hardening, grain refinement and the decrease of annealing temperature.