Tribological properties of non‐ferrous coating lubricated with rapeseed oil containing lubricant additives

Abstract

With the increasing requirements of environmental protection, using lead, hexavalent chromium and other heavy metals will be prohibited in different surface coatings. In this paper, the non‐ferrous CrN coatings and the rapeseed oil were chosen as friction pair and biodegradable lubricant. The tribology properties were investigated using SRV‐IV reciprocating friction wear test. The worn surface of CrN coatings was observed and analysed using scanning electron microscopy and X‐ray photoelectron spectroscopy. The results indicate that the rapeseed oil containing 1 wt.% MoZn (MoDTC (molybdenum dithiocarbamate) + ZnDTP (zinc dithiophosphate) (1 : 3)) exhibits better friction‐reducing properties than the rapeseed oil containing 1 wt.% PN (an amine salt of an alkoxylphosphate) additives, whereas the rapeseed oil containing 1 wt.% PN additive exhibits better wear resistance properties than the rapeseed oil containing 1 wt.% MoZn additives. This is partly attributed to the tribophysical and tribochemical reactions between the lubricant and the CrN coating sliding surfaces. Copyright © 2012 John Wiley & Sons, Ltd.

Friction and wear performance of MoDTC‐containing and ester‐containing lubricants over steel surfaces under reciprocating conditions

“…The esters can also interfere with adsorbed or chemisorbed films, changing their effectiveness. However, although some work have been made regarding the use of ester‐based vegetable oils, the role of MoDTC in the presence of ester base oils is not so well documented in the literature. Nevertheless, it is worth mentioning the work of Muraki, Aoyanagi and Sakaguchi, who studied the effect of MoDTC and ZnDTP additives on friction and wear under rolling, elastohydrodynamic conditions using a polyalphaolefin and a polyol ester as base oils.…”