The results of the heat treatments (350 and 535 °C) prior to FSP are observed in Fig.1 for alloy A and Fig. 2 for alloy
B, which are also compared to untreated FSPed samples. In all cases, after FSP a heat treatment was applied at 490
°C for different hold durations (1, 5, 20 and 60 min) to simulate the tensile test temperature, and then quenched in
water to examine the kinetics of grain growth. This temperature was selected because it was associated with the onset
of the reduction in tensile properties as a consequence of the AGG presence. Both heat treatments prior to FSP
improved the thermal stability of microstructure, the treatment at 350 °C being more effective; delaying the onset of