  We develop an analytical model of adhesive wear between two unlubricated
rough surfaces, forming micro-contacts under normal load. The model is based on
an energy balance and a crack initiation criteria. We apply the model to the
problem of self-affine rough surfaces under normal load, which we solve using
the boundary element method. We discuss how self-affinity of the surface
roughness, and the complex morphology of the micro-contacts that emerge for a
given contact pressure, challenge the definition of contact junctions. Indeed,
in the context of adhesive wear, we show that elastic interactions between
nearby micro-contacts can lead to wear particles whose volumes enclose the
convex hull of these micro-contacts. We thereby obtain a wear map describing
the instantaneous produced wear volume as a function of material properties,
roughness parameters and loading conditions. Three distinct wear regimes can be
identified in the wear map. In particular, the model predicts the emergence of
a severe wear regime above a critical contact pressure, when interactions
between micro-contacts are favored.
