Deformation twinning occurred in various materials including metals, intermetallics, ceramics, superconductors, and even geological systems. The rate of twin growth depends on the material system, but there were no crystallographic models to understand the mechanisms of slow twin growth. The physics of twin growth was presented for body-centred cubic-Ti alloys where it was shown that octahedral interstitial sites were not conserved at the twin-matrix interface where O resides. The predicted activation energy for twin growth correlated well with experimental values for the diffusion of oxygen. These models will have a broad application in understanding the twinning process and designing advanced materials.

Why Twins Do Not Grow at the Speed of Sound All the Time. P.G.Oberson, S.Ankem: Physical Review Letters, 2005, 95[16], 165501 (3pp)