Deformation And Heat Treatment Of Magnesium Alloy

Magnesium alloys are becoming more and more attractive metal materials in the recent years due to their low density, high specific strength, well damping property and so on. In the early time, however, magnesium alloys are mainly used in the field of military industry in which the cost is not the main concern. Therefore the fundamental research and development are limited, which have restricted their applications. At present, the main research tendency is to design and develop new magnesium alloys with improved performance. Another approach to improve the properties of magnesium alloys is to modify the process of current alloy systems. This may become more rapid, economic and effective way for the application of magnesium alloys. Deformation and heat treatment are two major effective methods to improve the properties of metallic materials. The present work has investigated systematically the process development for widely used commercial magnesium alloys, AZ80 and AZ31, by a combination of deformation and heat treatment. Firstly, the effects of the parameters of deformation and heat treatment to the property and microstructure are investigated separately. The study of deformation mainly focused on the recrystallization and heat treatment on the effect of age-hardening. On the base of above discussion, the appropriate processing parameters are arranged in pairs or groups to optimize the process gradually based on the hardness and microstructure measurements and the optimum process is selected finally. In the meanwhile, the interaction between deformation and aging is analyzed. The result shows the interaction process can improve the properties more effectively. The discussing results indicate that the combination of two-step aging heat treatment and deformation can upgrade the hardness of AZ80 by 80% than the original statement. At the same time, the microstructure is fined remarkably. Therefore, it is the optimum process to enhance the properties of AZ80. The improved hardness value of AZ31 is less than that of AZ80. Because the amount of precipitates during aging heat treatment is so little that the interactions between deformed structure and precipitate are not obvious. However the microstructure can be refined remarkably by an appropriate process.