Anisotropie de frottement des films minces métalliques déposés par Glancing Angle Deposition (GLAD) : Aspects morphologiques et cristallographiques

One promising technique for introducing friction anisotropy in a surface is the Glancing Angle Deposition (GLAD). This method has demonstrated a wide range of possibilities for creating films with diverse morphologies and structural characteristics, which may induce anisotropy in various physical properties. However, the study of friction anisotropy in GLAD films remains limited, potentially leading to the underutilization of this technique in tribological applications. In this context, this thesis aims to investigate the potential use of GLAD to induce friction anisotropy, with a particular focus on the influence of morphological and crystallographic factors. Two metals, tungsten (W) and molybdenum (Mo), were selected for deposition under varying conditions. Scratch tests were conducted with different normal loads and scratching directions to determine whether friction anisotropy could be consistently achieved and how it manifests. The results indicate that not only is it possible to obtain friction anisotropy through GLAD, but also that different types of anisotropy can be observed. This anisotropic behavior seems to be primarily governed by the film’s morphology, particularly through the control of plastic deformation and column-column interactions. Furthermore, the type of material and deposition angle were found to significantly influence friction anisotropy, with Mo films exhibiting more complex anisotropic characteristics than W films. Although the significant impact of morphology on the behavior of most films was evident, a Mo film demonstrated that other factors may also contribute to atypical frictional responses.