Hall-Petch parameters in tension and compression in cast Mg–2Zn alloys

The flow stress in tension and compression has been measured as a function of plastic strain in Mg–2Zn castings with grain sizes ranging from 55 to 340μm. Hall-Petch parameters have been calculated and are compared to those previously reported. In contrast to the behaviour of pure Mg grain refined with Zr and of hot-worked and recrystallised pure Mg and Mg–Zn alloys, the cast material shows little tension/compression asymmetry of the flow stress. The possible effects of texture and of twinning are noted.