Computer simulations of dislocation glide in a matrix containing coherent spherical precipitates were presented. These particles had a lattice mismatch, and their strengthening contribution (critical resolved shear stress) was derived. The size-distribution and 3-dimensional spatial arrangement of the particles were close to those of an actual Ostwald-ripened crystal. An example of such a system was a Cu-rich Cu–Co alloy. The simulations were based upon local stress equilibria along the dislocation line, and elastic dislocation self-interaction was fully allowed for. Perfect dislocations as well as pairs of Shockley partials were considered. The effect of dislocation dissociation upon the critical resolved shear stress was deduced for large and small particles. Two particle arrangements, of differing lattice mismatch and volume fraction, were considered. Two approaches were used to simulate the dissociated dislocation. In the first one, a pair of partials which enclosed a stacking fault was simulated. The second approach was a major simplification which significantly reduced the numerical effort. It was shown that the simplified model nevertheless reproduced the basic features of dislocation dissociation.

Computer Simulations of the Glide of Dissociated Dislocations in Lattice Mismatch Strengthened Materials. V.Mohles: Materials Science and Engineering A, 2002, 324[1-2], 190-5