<p>The present work examined various parameters: mainly degassing, strontium addition, TiB₂ addition, and the amount of hydrogen. Thus, nine conditions were created for each alloy. In addition, the performed heat treatments on the alloys were analyzed. Grain size, the morphology of silicon particles, and pores were measured. Regarding mechanical properties, hardness and impact strength were evaluated. The crack propagation modes for the samples subjected to the impact testing were examined. The results show that the oxides contained in alloys can contribute to pore formation, just as the presence of fine TiB₂ particles can create micropores. Platelet-shaped <i>β</i>-Al₅FeSi particles participate in pore nucleation but also act as a barrier to pore growth. Changing the metallurgical parameters (degassing, strontium, titanium diboride, hydrogen) has no significant effect on the hardness of the samples of the three alloys. It is the aging temperature that allows the hardness of the samples to be increased to a maximum. During impact testing, unmodified eutectic silicon can be cleaved lengthwise. This mechanism is characteristic of brittle fracture, which impairs impact resistance. However, the modified eutectic silicon prevents crack propagation through the structure. The crack must propagate through the <i>α</i>-aluminum of the eutectic, bypassing all the small silicon particles. This fracture mechanism is characteristic of ductile fracture, which increases the impact strength of certain alloys.</p>