Rolling Deformation Of AZ31 And Hot Roll Bonding Of AZ31/Al

Hot rolling has been widely applied to the manufacture of wrought magnesium alloy sheets. In this paper, microstructure and mechanical properties of electromagnetic continuous casting (EMCC) AZ31 magnesium alloy subjected to hot rolling were investigated, Furthermore, rolling compound was performed on AZ31 and L2 commercially pure (CP) Al to obtain AZ31/Al composite plate. The results are as the following.(1) During hot rolling process of AZ31, with increasing the deformation of hot rolling, twinning plane transformed from coarse lentoid to fine batten with twins increasing, and the extent of DRX was increased.(2) With increasing temperatures, DRX more easily occurred, and the nucleation sites of new grains changed from twinning to original grain boundaries. These behaviors could be due to the dependence of deformation mechanism of magnesium alloys on temperatures.(3) The influence of strain rate on DRX was also studied. According to the relationship of Z=εexp(?), as T increases or s decreases, Z becomes smaller and grain size decrease. When Z reaches to a certain critical value, the DRX mode varies.(4) Under the condition of 30%reduction per rolling pass with a temperature of 370℃, excellent surface quality was obtained. After three passes rolling process,tensile strength and elongation along rolling direction were 280～290 MPa and 24%-29%, respectively, normal to rolling direction the tensile strength and elongation were 290 to 310 MPa and 17%-22% respectively.(5) With increasing the deformation of hot rolling, strong texture (0002) parallel to rolling direction was observed. There is only slightly decrease in strength of texture (0002) after annealing.(6) The more than50%deformation of rolling compound and a minimum temperature of 425℃are required to produce good quality AZ31/Al sheets. Annealing temperature over 275℃resulted in hard brittle interephases in AZ31/Al compounding surface, and a better temperature was below 250℃.