Recent progress in atomic-scale computer simulation of such metals was reviewed. While most research had successfully used many-body central-force interatomic potentials, they were inadequate for treating metals (such as α-Ti and α-Zr) which had an unfilled d-electron band. The resultant non-central character of the atomic bonding was shown to have subtle but significant effects upon dislocation properties. Deformation twinning was an important process in the plasticity of hexagonal close-packed metals, and modelling was used to investigate the factors that controlled the structure and mobility of twinning dislocations. Simulations showed that twinning dislocations were sometimes generated following the interaction of crystal dislocations with twin boundaries. This could produce the highly mobile boundaries which were observed experimentally. Computer simulation had also been used to determine the numbers and arrangement of the defects produced by primary displacement-cascade damage in several hexagonal close-packed metals. The numbers were similar to those found in cubic metals, and were considerably smaller than those expected from earlier models. Many self-interstitial atoms clustered in cascades, to form highly glissile dislocation loops, and so contributed to 2-dimensional material transport in damage evolution.

Atomic-Scale Modelling of Dislocations and Related Properties in the Hexagonal-Close-Packed Metals. D.J.Bacon, V.Vitek: Metallurgical and Materials Transactions A, 2002, 32[3A], 721-33