EFFECT OF DYNAMIC RECRYSTALLIZATION ON MICROSTRUCTURE EVOLUTION AND TEXTURE WEAKENING DURING ANNEALING OF HIGH SPEED ROLLED AZ31 MAGNESIUM ALLOY SHEETS

Magnesium AZ31 (Mg-3 wt. % Al-1 wt. 10 Zn) alloy sheets were rolled at a high speed of 1000 m/min at 100 degrees C to reductions of 30% and 49%. Annealing was then conducted on the as-rolled specimens at temperatures of 200 degrees C and 350 degrees C for different times. The microstructure was characterized by optical microscopy and the macrotexture was analyzed by X-ray diffraction. The as-rolled microstructure of the specimen subjected to the reduction of 30% was heavily twinned and shear handed, while a partially dynamically recrystallized and twinned microstructure was observed at the reduction of 49%. Effect of the initial microstructure on static recrystallization behavior and texture evolution during annealing was studied at different temperatures. Texture weakening was found during annealing at both reductions. However, the weaker texture can be achieved in the specimen subjected to the reduction of 30% than that of 49%.