Formation Mechanism of the Frictionally-Formed Protective Coating by Using Self-Repairing Material under Sliding Friction

Abstract

Sliding experiments lubricated with hydroxyl silicate magnesium particles as additive were performed under ambient condition and different loads by using an AMSLER friction and wear tester. The surface topographies and compositions of worn surface of 45 steel rings were analyzed by SEM and EDAX. The experimental results show that the friction load had great effect on generation of the frictionally-formed protective coating. No protective coating formed on the worn steel surface under lower friction load. However, a smooth and continuous protective coating can be developed on the worn surface of the steel when the friction load is high enough. The chemical composition of the protective coating is roughly the same as the additive. The additive can be fractured, stretched and flowed along the sliding direction under high contacting stress and instantaneous flash temperature, which result in coating being formed.

Film Formation Property of Mineral Particles as Grease Lubricant Additives at Different Friction States

“…So the conclusion can be obtained that there no self-repairing film formed on the surface worn under Rolling-Sliding friction. In the previous works [8][9], a research finding had been generalized that the additive can be fractured, stretched and flowed under high contacting stress and friction heat, which result in coating being formed. At the same time, the friction heat and friction energy produced by the friction process depend on the relative displacement between the two parts of the friction pairs.…”