  Simulation of subgrain growth during recovery is carried out using
two-dimensional discrete dislocation dynamics on a hexagonal crystal lattice
having three symmetric slip planes. To account for elevated temperature (i)
dislocation climb was allowed and (ii) a Langevin type thermal noise was added
to the force acting on the dislocations. During the simulation, a random
ensemble of dislocations develop into subgrains and power-law type growth
kinetics are observed. The growth exponent is found to be independent of the
climb mobility, but dependent on the temperature introduced by the thermal
noise. The in-depth statistical analysis of the subgrain structure shows that
the coarsening is abnormal, i.e. larger cells grow faster than the small ones,
while the average misorientation between the adjacent subgrains remains nearly
constant. During the coarsening Holt's relation is found not to be fulfilled,
such that the average subgrain size is not proportional to the average
dislocation spacing. These findings are consistent with recent high precision
experiments on recovery.
