The effect of solute on discontinuous dynamic recrystallization

A series of Cu–Sn alloys (pure Cu, Cu–0.2Sn, Cu–2Sn and Cu–5Sn) has been prepared to experimentally test the effect of solute on discontinuous dynamic recrystallization (DDRX) as a function of both temperature and strain rate. Hot compression tests were performed and the microstructure was characterized using optical and scanning electron microscopy. Solute additions tend to broaden the peak in the flow stress curve and increase the peak stress, peak strain and steady-state stress. A reduction in the DRX grain size and a retardation of the kinetics of recrystallization are observed with solute additions, although the effect saturates at 2Sn. A recently published, physically based model for DDRX of pure Cu has been extended to include the effect of solute. The effect on the plastic response of the material and the mobility of high-angle grain boundaries was incorporated and, through comparisons between experiment and simulated DRX phenomena, it is concluded that solute must also significantly affect the nucleation stage of DDRX. A model is developed for the effect of solute on the nucleation of DDRX in Cu–Sn alloys and comparisons with experiment indicate that the principal effects are well captured. Important areas for future work are discussed.