Hot deformation behavior of hot-rolled AZ31 and AZ61 magnesium alloys

The hot deformation behavior and microstructure of AZ31 and AZ61 alloys processed by the hot-rolled technique were investigated over a strain rate range from 1 x 10(-4) to 1 x 10(-1) s(-1) and temperatures ranging from 350 to 500 degrees C. Alloys were manufactured by melting and casting, and then hot-rolled at two temperatures of 350 and 450 degrees C. Tensile test revealed elongations of over 300% in the two alloys. The highest elongation value of 321% at a strain rate of 3 x 10(-3) s(-1) was achieved in the AZ61 alloy with a hot-rolling temperature of 350 degrees C. The hot tensile tests showed that there are some differences in ductility between the AZ31 and AZ61 alloys with the same rolling process specifically at low strain rates. A small enhancement in ductility is found using a lower temperature for hot-rolling at 350 degrees C compared to 450 degrees C due to improved grain refinement. It is suggested that the dominant deformation mechanism was glide controlled dislocation creep based on the stress and grain size exponent, and activation energy. (C) 2013 Elsevier B.V. All rights reserved.