Dependence of deformation behaviors on temperature for twin-roll casted AZ31 alloy by processing maps

• Main Authors: Chenchen Zhi, Lifeng Ma, Weitao Jia, Xiaojiao Huo, Qinhong Fan, Zhiquan Huang, Qichi Le, Jinbao Lin
• Format: Article
• Language: English
• Published: Elsevier 2019-11-01
• Series: Journal of Materials Research and Technology
• Online Access: http://www.sciencedirect.com/science/article/pii/S2238785419307306

Hot deformation behaviors of the Twin-roll Casted (TRCed) AZ31 magnesium alloy were studied by uniaxial compression tests under a temperature range of 473–673 K and strain rate of 0.001–1s−1. The effects of the temperature on activation energy and recrystallization were discussed, and the degree of DRX had also been discussed in detail considering the activation energy and processing maps. The results showed that the activation energy is significantly dependent on temperature, and its value increases gradually with the increasing of temperature. The activation energy increased to 192 kJ/mol when the deformation temperature is within 473–673 K. The values of Q are close to the energy of lattice self-diffusion of magnesium alloy in the region of 473–523 K and 523–623 K. Basal slip and twinning are the main deformation mechanisms in the region of low temperature (473–523 K). The critical shear stress of non-basal slips decreases with the increasing of temperature, so prismatic slips and pyramidal slips are easy to initiate when the deformation temperature raise to 523–623 K. The optimized processing parameters at 523–580 K/0.007–0.018s−1 of TRCed AZ31 alloy were obtained from processing maps. Through the verification of the microstructure, it was found that the best performance occurs under the deformation condition of 573 K/0.01s−1. More importantly, the practical rolling shows that the suitable processing fitting of the formed area is correct. Keywords: Twin-roll cast AZ31 alloy, Hot compression, Processing map, Deformation mechanism