Formation mechanism of recrystallisation internal friction peak and its application to determine the recrystallisation temperature of deformed pure Cu

The formation mechanism of a recrystallisation internal friction (IF) peak superimposed on a grain boundary (GB) IF peak for deformed copper was studied. The P1 peak, associated with the recrystallisation process, was observed at ∼ 599 K (2 K/min) during the first heating process. Subsequently, the P2 peak, located at ∼ 510 K (0.2 Hz), corresponded to GB relaxation during the cooling process. The P1 peak showed minor relaxation at higher frequencies owing to the influence of GB relaxation. To accurately determine the temperature of the P1 peak in this scenario, two methods were used: fitting the measured IF spectra and performing IF measurements at lower frequencies and/or with faster heating rates to minimise the impact of GB relaxation. This work investigated the formation mechanism of the recrystallisation peak and supplemented the method for determining the recrystallisation temperature through IF measurements when the GB peak occurs at a nearby temperature.