Understanding Deformation Behavior of AM50 and AZ31 Magnesium Extrusions with Various Heat Treatments in Comparison with AA6063 and AA6082 Aluminum Extrusions

Abstract

The effect of the cooling methods after extrusion and subsequent heat treatment on mechanical properties of AM50 and AZ31 were studied. For each alloy, the influence of orientation of the specimen with respect to the extrusion direction was also investigated in comparison with 6063 and 6082 aluminum extrusions. The results obtained by hardness tests and Charpy impact tests demonstrate that heat treatments have no significant effect on hardness and fracture energy values of AZ31 and AM50 alloys. Tensile test results also generally support this statement except for that supersaturated solid solution (solution heat treatment followed by quenching in water) AZ31 plate shows a significant loss in yield strength, but increase in elongation. However, the fracture energy obtained by Charpy impact test and its tensile strength is similar to those under the different heat treatment conditions. AZ31 and AM50 extrusions exhibit highly anisotropic behavior, especially in terms of elongation values. AA6063 and AA6082 aluminum extrusions display low anisotropy and provide high fracture energy values corresponding to their elongation values. However, AM50 and AZ31 alloys provide low fracture energy values regardless of their elongation values.