Various Aspects Influencing the Fracture Behavior of Impact-Tested Zr-Containing Al–Si–Cu–Mg–354-Type Alloys

The present work was carried out on Al–Si-Cu-Mg-354 alloy to investigate the role of transition metals addition (mainly Zr, Ni and Mn) as well as heat treatment on its performance at ambient/room temperature (25 °C). Mechanical properties were studied using tensile and impact testing, whereas the microstructure was investigated using field emission scanning electron microscopy (FESEM) and transmission electron microscopy (STEM). The fracture surfaces of selected samples prepared from impact-tested bars were examined applying FESEM. The results show that the proposed additions enhanced the alloy tensile and impact properties. The T6-tempered alloys revealed higher tensile strength than T5-tempered alloys. The impact properties of the alloys are highly influenced by the Al 2 Cu phase particles rather than the eutectic silicon particles. Thus, the impact properties show no significant variations with respect to the condition studied, i.e., the total energies absorbed by the five alloys in the as-cast condition are close in their values, as is the case for the T5- and T6-treated conditions. Due to the precipitation of a fairly large amount of insoluble intermetallics, all fractures were brittle in nature.