By using high-resolution electron microscopy, an investigation was made of the initial stages of the high-pressure torsion-induced crystalline-to-amorphous transformation. It was found that the deformation-induced amorphization began from dislocation core regions in the interior of grains, and from grain boundaries. It was suggested that the energy stored in the dislocations, and the energy stored in the grain boundaries, both contributed significantly to driving the crystalline-to-amorphous transformation.

Amorphization of TiNi Induced by High-Pressure Torsion. J.Y.Huang, Y.T.Zhu, X.Z.Liao, R.Z.Valiev: Philosophical Magazine Letters, 2004, 84[3], 183-90