Tensile and Impact Properties of Aged Al6Si0.5MgxCu (x=0, 0.5, 1, 2 and 4 wt %) Alloys

Abstract

Effects of the artificial aging temperature on the mechanical properties of the Al6Si0.5Mg alloy containing 0.5–4 wt% Cu were studied. Tensile tests were performed at a constant strain rate of 10−3 s−1 for all aging conditions. In addition, the peak-aged samples (1 h at 225°C) were tested at three different strain rates of 10−2 s−1, 10−3 s−1, and 10−4 s−1. Tensile strength was found to increase with aging temperature, and the maximum was attained at the peak-aged condition (1 h at 225°C). The addition of Cu (up to 2 wt%) resulted in an increase in tensile strength, and maximum strength was found with the addition of 2 wt% Cu. Strain rates affected the tensile properties significantly. At higher strain rates, higher strengths were obtained; however, these samples showed poor ductility. The effects of the aging temperature on the impact strength (absorbed energy) of the alloys were studied. The impact strength decreased with the aging temperature, and the minimum was found during the peak-aged condition. Further increases in the aging temperature beyond 225°C slightly increased the absorbed energy. Peak of mechanical properties were obtained with approximately 2 wt% Cu. The increment of copper seems to have a remarkable impact on mechanical properties, especially after the aging process, thus indicating a significant increase of the ultimate tensile strength (UTS) and yield strength (YS).