Abnormal flow behavior and serrated flow in Al–Li single crystals

Deformation behavior and serrated flow of binary Al–Li single crystals were investigated in the temperature range 200–453 K at a strain rate of 5.6×10−3 s−1. Abnormal flow behavior, i.e. flow stress increasing with increasing temperature, was observed in the crystals both in solid solution and underaged conditions, but in different temperature ranges. Serrated flow was observed in the crystals in the underaged state, but not in the solid solution condition, which indicates that serrated flow is related to shearing of δ′ particles. Analysis of the serrated flow curves showed that both stress drops and elapsed time for serrations varied irregularly with increasing strain and no correlation between them was found.