  Nickel-based superalloys play a major role in many technologically relevant
high temperature applications. Understanding and predicting the evolution of
the phase microstructure during high temperature creep together with the
evolution of the dislocation microstructure is a challenge that up to date has
not yet been fully accomplished. Our two-dimensional coupled
phase-field/continuum dislocation dynamics model explains microstructural
mechanisms which are important during the early stage of rafting in a single
crystal system. It shows how $\gamma/\gamma'$ phases and dislocations interact
giving rise to realistic creep behavior; no phenomenological fit parameters are
required.
