The role of indentation size effect on the abrasive wear behaviour of ductile metallic materials: A nanotribological study

The abrasive wear behaviour of many materials is closely related to their hardness. However, classical wear models do not take into consideration the contact scale dependence of hardness, an effect commonly known as indentation size effect (ISE). In this work is carried out an evaluation of the abrasive wear behaviour of ductile metallic materials at the nanometric contact scale, by performing AFM-based nanoabrasive wear tests. It is shown that, at the contact scale of a single abrasive asperity, the wear response of these materials is closely related to their nanohardness and not to their microhardness, and that surface roughness also plays an important role on the onset of wear. The results strongly suggest that the influence of contact scale on the wear behaviour can be extended to any ductile material presenting ISE, not only under conditions of abrasive wear but also in other types of wear where hardness has a significant contribution (e.g. adhesive wear), as long as the scale of deformation is within the range where ISE occurs.