Nano-Structured Lubricants for Ball-Bearing Applications in Space

European Space Agency (from 2011-03-07 to 2014-03-06)

Grant closed
The project is the second of a three-step program called ITI (Innovation Triangle Initiative) and financed by the European Space Agency. The research field is the study of new solid lubricants suitable for aerospace applications. The goal is to assess the tribological properties of coatings made of metal dichalcogenides (MoS2 and WS2) deposited by Supersonic Cluster Beam Deposition (SCBD). Metal dichalcogenides are largely used as solid lubricants because of their layered structure, similar to graphite, although the lubricating properties are narrowed down by the oxidation of the layers. The nanostructured form, in particular onion-like particles, can reduce this effect; thus the potential advantage of using SCBD which, with respect to other PVD techniques, can produce films with a larger fraction of onion-like particles, randomly dispersed in the amorphous matrix. The tribologic performance of coatings deposited with different process parameters will be tested by pin-on-disc method either in air or nitrogen. The most promising combination will be used to coat races of ball bearings typical of spacecraft mechanisms. The bearing torques and bearing lifetime will be measured in both vacuum and air environments. The expectation is that the tests of SCBD deposited WS2 and MoS2 will show friction coefficients comparable to benchmark coatings, but longer lifetimes.

Coordinator: ESR Technology Ltd

Referent: Claudio Piazzoni