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.