Fatigue crack growth behavior of Al–Mg–Sc alloy

The Al–Mg–Sc alloy sheets were prepared using water chilling copper mold ingot metallurgy processing which was protected by active flux. The microstructure and mechanical properties of the Al–Mg–Sc alloy were studied by means of transmission electron microscopy (TEM), scanning electron microscopy (SEM), optical microscopy (OM) and tensile and fatigue crack growth (FCG) rate tests. The FCG rate (da/dN) with stress intensity factor range (ΔK) was discussed within the Paris region. The Al–Mg–Sc alloy exhibited high resistance against fatigue crack growth, and the second phase of Al3(Sc1−xZrx) was found to be the main factor influencing the FCG resistance.