Durability and wear mechanisms of easy-to-clean coatings on glass assessed by in situ tribometry
In the present work, we evaluate the durability and study the wear mechanisms of ETC coatings on glass substrates using an in situ tribometer (TribTik) equipped with a camera system; this allows one to image, in real time, the contact area between the substrate and the abrading counterpart. Through this unique combination, the instantaneous friction coefficient and the contact area’s status can be monitored and correlated in situ, thus offering the opportunity to abort the test at critical stages of the wear process and study its progression.
The morphology and composition of the wear tracks are examined at different stages to understand the wear mechanisms of the ETC. We demonstrate, with the support of optical, SEM and EDX analyses that the instantaneous friction coefficient and the obtained in situ images correlate very well with the wear process. The progression of the wear mechanism is then defined as follows: 1) generation of unconsolidated debris, 2) formation of a layered tribofilm, 3) cracking of the tribofilm, and 4) damage to the glass substrate.