Effects of Strain Energy on the High Temperature Mechanical Properties of AZ61 Mg-Al-Zn Alloy

摘要

Magnesium (Mg) alloys are characterized with lightweight, heat conduction and anti-vibration...etc. They become popular among electric equipment for household and 3C industry. In addition, as for transportation industry, automobile manufacturing in particular, Mg alloys will be developed to lighten the weight of cars, owing to environmental protection and energy-saving. However, because Mg is not easy to deform under the room temperature, the body of the car is forged under a high temperature to increase its flexibility. In order to investigate the plastic deformation and the properties of Mg-Al-Zn alloy under a high temperature, this research focused on the Mg alloy AZ61 (92.5 wt% Mg, 6.5 wt% Al and 1.0 wt% Zn) - working under the re-crystallization temperature and transmitting the dislocations to strengthen the rapid diffusion of the atom with its strain. Experimental results showed that the extension of AZ61 worked the best under the room temperature because most of its stress was removed after one-hour annealing from 400℃. But after warm rolling of 150℃, many dislocations were induced, the atom became hard to move and the extension reduced under the room temperature as the strain increased. At the same time, the ultimate strength and yield strength increased with the strain. On the contrary, it was exactly the opposite under a high temperature due to the strain could increase the diffusion of atom under such condition.