Effects of heat treatment and testing temperature on the tensile properties of Al–Cu and Al–Cu–Si based alloys

Abstract

AbstractThe present study aimed at investigating the effects of different additives and heat treatments on the mechanical properties of Al-2.4 %Cu-1.2 %Si-0.4 %Mg-0.4 %Fe-0.6 %Mn alloy, a casting alloy intended for automotive applications. The research was accomplished through a study of the tensile properties in both as-cast and heat-treated conditions, where the effects of different heat treatments, i. e., T5, T6, T62 and T7, commonly applied to aluminum casting alloys were evaluated at ambient and at high temperature (250 °C), using different holding (stabilization) times at testing temperature. Six alloys were prepared using 0.15 wt.% Ti grain-refined alloy – considered as the base alloy B0, and alloys B1 and B2, and D0, D1, and D2 containing various amounts of Ni, Cr, V, Zr and La, added individually or in combination. The D-series alloys had a higher Si content of 8 wt.%. The results showed that T6 and T62 treatments provide the best improvements in strength at room temperature. At high temperature, the tensile properties vary depending on the stabilization time and heat treatment. The best alloy quality is provided by B1 and D1 alloys in T62 (444/368 MPa) and T7 (430/360 MPa) conditions, respectively.