Experiment and simulation on the thermal instability of a heavily deformed Cu-Fe composite

▶ Fe fibers undergo thermal instability at temperature above 600 °C. ▶ Longitudinal boundary splitting is the dominant instability process. ▶ Instability of cylindrical fibers is controlled by breakup, growth and coarsening. ▶ Breakup times can be predicted by Rayleigh perturbation model accurately. ▶ The increase of fiber diameters is due to the coarsening and growth.