Effects of temperature and strain rate on material strength properties in aluminum alloy with high amount of copper based on A6082 aluminum alloy and its material modeling

From a recycling perspective, it is necessary to clarify the effect of impurities on the material strength properties of aluminum alloys. In this study, the effects of temperature and strain rate on the material strength properties of A6082 aluminum alloy with copper addition as an impurity were investigated. Uniaxial tensile tests showed that an increase in the amount of copper had a positive effect on the material strength properties of A6082 aluminum alloy. It was found that the material strength exhibited negative temperature dependence and positive strain rate dependence, regardless of the amount of copper addition. When examining how the deformation of this alloy is governed by the thermal activation process of dislocation motion, it was found that the flow stress increases due to the precipitation phase caused by copper addition, which affects the athermal component of the stress. Therefore, the thermal component of stress dependent on temperature and strain rate is almost constant, irrespective of copper addition. Furthermore, the relationship between loading curvature-displacement curve and strain rate was investigated using micro-indentation testing. The experimental conditions were within the range affected by the thermal component of stress, resulting in indentation properties that qualitatively matched the results of uniaxial testing.