Precipitation of nanoparticles in metal alloys?

Is it possible to simulate precise precipitation of nano sized particles in age hardened alloys in LAMMPS?
Where should I start in terms of interatomic potentials?

step 1: search the published literature, whether the process you want to study, has been simulated AT ALL. if not, it is unlikely that you will figure out a method on your own, or that somebody on this list has the time to figure it out for you and tell you (before publishing it on their own first).
step 2: if yes, see what simulation method was used. if it was MD, then there is a good chance, it can be done with LAMMPS
step 3: compare the technical section of the paper(s) with the LAMMPS manual and try to follow and implement them with LAMMPS. the type and parameterization of potentials used should be listed and thus it should be straightforward to obtain suitable potentials
step 4: after reproducing the published results, set up your specific system of interest following the same or an equivalent protocol.