Self-lubricating composite bearings: Effect of fibre length on its tribological properties by DEM modelling

Maria Villavicencio (1, 2, 3, 4) , Mathieu Renouf (2, 5) , Aurélien Saulot (1, 5) , Yann Michel (3) , Yves Mahéo (4) , Guillaume Colas (6) , Tobin Filleter (6) , Yves Berthier (1, 5)

1 LaMCoS - Laboratoire de Mécanique des Contacts et des Structures [Villeurbanne]
2 PMMD - Physique et Mécanique des Milieux Divisés
3 CNES - Centre National d'Études Spatiales [Toulouse]
4 SKF - Aerospace [Saint-Vallier]
5 InTriG - International Tribology Group
6 Department of Mechanical and Industrial Engineering

Self-lubricating polymer-based composites are used in space and in aircraft mechanisms as materials for solid lubricated systems. Such composites mostly consist of a polymeric matrix and fillers of two kinds: hard fillers (fibres made of glass, or of minerals) and solid lubricating particles (made of MoS 2). Their advantages are that they provide their own lubrication, and they can be used in both very high and very low temperatures (from −40 up to ~200 F). Precision ball bearings with these composites are manufactured since the 60's in these bearings the retainer material itself provides the lubrication. From the experimental analyses implemented (X-ray tomography, SEM observations, and experiences in a tribometer); it is possible to observe that the geometry of the fillers has a strong influence on the third body rheology. Nevertheless, the confined nature of the contact does not allow in-situ observation. To overcome this difficulty a combined numerical/experimental approach is carried out. To be able to reproduce the evolution of third-body particles within the contact, Discrete Element Methods (DEM) is used. Such an approach allows to represent wear: by the construction of an equivalent continuous medium resulting from the incorporation of interaction laws between the discrete particles. The motivation to this work is the understanding of the impact of filler geometry o tribological behaviour of these materials. More specifically, the goal is to study the influence of the fibre length in the tribological behaviour of self-lubricating composites by Discrete Element Methods (DEM).

Mots clés: Composites; Space tribology; Self-lubricating material; DEM; Bearing

Domaines: Matériaux; Mécanique des solides [physics.class-ph]

Maria Villavicencio, Mathieu Renouf, Aurélien Saulot, Yann Michel, Yves Mahéo, et al.. Self-lubricating composite bearings: Effect of fibre length on its tribological properties by DEM modelling. Tribology International, 2017, 113, pp.362 - 369. ⟨10.1016/j.triboint.2016.12.022⟩. ⟨hal-01555615⟩