Lubricant additives are chemical compounds of an organic or organometallic nature, incorporated into lubricating oils or greases at levels ranging from less than 1% to more than 25%, depending on the case, either to give the base oils or greases properties they do not naturally possess, or to improve their natural properties.
These additives, classified according to their very general mode of action, are divided primarily into those that act chemically in the lubricant mass and those that act chemically on the surfaces.
These two product categories were examined in the first part [BM 5 343].
The other additives studied in this second part are those whose action is physical, either in the lubricant mass, or at the liquid-solid, liquid-liquid or liquid-gas interfaces, and finally, those whose action is physiological. This second part is completed by some economic and commercial data in the appendix "For further information" [Doc.BM 5 344].
Readers may also wish to consult the articles on lubricants published in this treatise: