Published 04/10/2025 at 909 × 617 in The Effect of Microstructural Features, Defects and Surface Quality on the Fatigue Performance in Al-Si-Mg Cast Alloys Figure 20. Beginning of crack initiation in as-cast condition: a) Alloy Cu 0; b) Alloy Cu 1.5. Figure 20. Beginning of crack initiation in as-cast condition: a) Alloy Cu 0; b) Alloy Cu 1.5.