Simulation of dislocation glide in dilute Fe-Cu alloys

The effects on dislocation glide of the substitutional element copper in solution in α-iron are being investigated by computer simulation. In the first phase, the critical stress for a 1/2 〈1 1 1〉 {1 1 0} edge dislocation to overcome configurations of either a single or two nearest-neighbour solute atoms is simulated. Molecular statics and dynamics methods are used to simulate effects at temperature equal to and greater than 0 K, respectively. Single copper atoms and nearest-neighbour pairs in the first atomic plane below the glide plane give the strongest barrier to dislocation glide, in partial agreement with elasticity theory. In addition to temperature, obstacle-spacing effects are considered.