The modelling of cohesion on the particle scale in granular matter [Vermeer et al., 2001]  has recently received increasing attention, because various important applications call for a microscopic foundation for the existing phenomenological continuum theories. Specifically for understanding the different behaviour of nano-powders and ordinary granular matter cohesion has to be taken into account. An example in this context is the so-called sinter-forging of nano-powders, i.e. pressure sintering at relatively low temperatures [Skandan et al., 1994] . We model the corresponding compaction by the rearrangement of a large number of grains by means of contact-dynamics. For this purpose we introduce an attractive force (cohesion) as well as rolling friction between the (round) grains. The latter turns out to be crucial for the stabilization of force chains.