Published online by Cambridge University Press: 10 February 2011
We report molecular dynamics simulations of the martensitic phase transition from bcc to hep in zirconium. We show the evolution of a laminated twinned microstructure, in which some plastic deformation has occurred to rotate the twins manifested as basal stacking faults. This rotation is such as to alter the twinning angle from the 60° between the hep variants to the 61.5° angle of the low energy (1011) twins. These are thus identified as a cause of microscopic irreversibility in the transition.