Computer modelling of slip in TiC

We have performed computer simulations based on tight binding to determine the probable dislocation dissociation reactions that will occur, and the pr eferred slip system, of TiC1.0 at 0 K. By calculating the barrier to the di ffusion of carbon atoms in different directions, and by considering the eff ect of changes in local stoichiometry, we have produced a model for the def ormation behaviour as a function of temperature. We find that, as observed experimentally, {110}[110] slip is preferred at low temperatures. At interm ediate temperatures in nonstoichiometric TiC we confirm that dislocations o n {111} with Burgers vectors of (a/2)[1 (1) over bar 0] will dissociate to form so-called 'synchro-partials', which will slip in preference to perfect dislocations on {110}. At high temperatures we predict that diffusion will result in {111} planes denuded of carbon on which the glide of Shockley pa rtial dislocations will form the favoured slip system.