Grain-Boundary Dynamics

Mott played a major part, with his collaborator Frank Nabarro (b. 1917) and in consultation with Orowan, in working out the dynamics of dislocations in stressed crystals. A particularly important early paper was by Mott and Nabarro (1941), on the flow stress of a crystal hardened by solid solution or a coherent precipitate, followed by other key papers by Koehler (1941) and by Seitz and Read (1941). Nabarro has published a lively sequential account of their collaboration in the early days (Nabarro 1980). Nabarro originated many of the important concepts in dislocation theory, such as the idea that the contribution of grain boundaries to the flow stress is inversely proportional to the square root of the grain diameter, which was later experimentally confirmed by Norman Fetch and Eric Hall. 

Mishin, Y., Suzuki, A., Uberuaga, B.P., Voter, A.F. Stick-slip behavior of grain boundaries studied by accelerated molecular dynamics. Phys. Rev. B 2007, 75, 224101-1-7. 

R.J. Jahn and P.D. Bristowe. A molecular dynamic study of grain boundary migration without the participation of secondary grain boundary dislocations. Scripta Metall., 24(7) 1313—1318, 1990. 

A. Luque et al Molecular dynamics simulation of crack tip blunting in opposing directions along a symmetrical tilt grain boundary of copper bicrystal. Fatigue Fract. Eng. Matls. Struct. 30, 1008-1015 (2007)... 

Tachibana A (2002) First- Principle Theoretical Study on the Dynamical Electronic Characteristics of Electromigration in the Bulk, Surface and Grain Boundary. In Baker SP (ed) Stress Induced Phenomena in Metallization. American Institute of Physics, New York, pp 105-116... 

Thus far, the discussion has been conhned to the static properties of grain boundaries. However, grain boundaries are metastable conhgurations and, as such, in response to external forces (e.g. thermal, mechanical), they exhibit dynamical behavior. Two of the more important ones are briefly mentioned here - grain-boundary migration and sliding. 

S. J. Plimpton and E. D. Wolf, Phys. Rev. B, 41, 2712 (1990). Effect of Interatomic Potential on Simulated Grain-Boundary and Bulk Diffusion A Molecular Dynamics Study. 

Kodiyalam S, Kalia RK, Kikuchi H, Nakano A, Shimojo F, Vashishta P (2001) Grain boundaries in gallium arsenide nanocrystals underpressure A parallel molecular-dynamics study. Phys Rev Letters 86 55-58 Leoni S, Nesper R (2000) Elucidation of simple pathways for reconstractive phase transitions using periodic equi-surface (PES) descriptors. The silica phase system. 1. Quartz-tridymite. Acta Crystallogr A 56 383-393... 

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