Associated Antifriction and Antiwear Actions in Tribological Behaviour of Colloidal additives

4 Associated Antifriction and Antiwear Actions in Tribological Behaviour of Colloidal Additives 

The examples chosen to illustrate the tribologic behaviour allow the various actions of such colloidal additives to be described. 

Friction reduction is mainly attributed to the adsorption film of the additive (organic molecule, soap molecules or encapsulated particles). The length of the organic shell (organic chains) is a first-order parameter according to Zisman experiments (where longer chains give lower friction). 

The exceptional wear reduction in the wear test is associated with the quasi-instantaneous build-up of a stable tribologic film from the adsorbed additive layer. The polycrystalline carbonate nature of the film results from the elimination of organic parts (oxidization) and the crystallization of ill-organized cores of the micelles or encapsulated particles under the physical conditions of the sliding contact (F 1 GPa, shear stress 10 s , oxidative species, flash temperatures, etc.). 

The action of the colloidal additives studied can be described as follows  

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