Friction and lifetime of a contact lubricated by a solid third body formed from an MoS1.6 coating at low temperature

A special test device has been designed to investigate the friction and wear behaviour of materials under very low temperature conditions. This paper describes an analysis of friction and wear in sliding contacts “lubricated” by a solid third body formed in situ from a non-stoichiometric MoS1.6 coating at 297 K, 223 K, 173 K and 123 K, under reciprocating kinematics in a gaseous atmosphere. It was found that under given test conditions, the friction coefficient was somewhat higher at low temperature than at room temperature under oxidising atmosphere. The lifetime was ten times lower at 123 K than at room temperature. Under no oxidising atmosphere the temperature does not effect on the friction value. The consequences of decreasing temperature on friction and lifetime are interpreted on the basis of experimental evidence and from the viewpoint of mechanics in order to evaluate third body flows and the rheology activated in the contact.