The number of {10•2} twins formed in a compressed Mg–5wt%Zn alloy increased when precipitate particles were present, reaching a maximum in the peak-aged condition. Particles were observed to promote twin nucleation, but inhibit twin growth. A simple model was developed to show that in peak- and over-aged condition the increase in twin number was accurately predicted by assuming the additional stress driving twin nucleation equates to the Orowan stress inhibiting twin growth.

Effect of Particles in Promoting Twin Nucleation in a Mg–5wt%Zn Alloy. J.D.Robson, N.Stanford, M.R.Barnett: Scripta Materialia, 2010, 63[8], 823-6