Tribological behavior of rapeseed oil mixtures with mono- and diglycerides

Abstract

The paper presents the results of tribological re-search on the rapeseed oil (RO) and its mixtures with mono- and diglycerides (MDG). The tests are carried out with four ball tribometer according to the standard DIN 51350/3. It is determined that the lubrication with pure RO and MDG, comparing it with reference oil, does not ensure good wear protection. However the lubrication with pure MDG can considerably reduce the friction losses. The lu-brication with mixture of RO and MDG is significantly more efficient comparing to its separate using. Optimal concentration of RO and MDG mixture which can enable to reduce the wear spot of the test ball up to 1.45 times and friction torque - up to 1.8 times comparing it to pure RO is determined. The paper presents discussion on the possible reasons of wear and friction reduction by the investigated mixture. It is seems likely that in RO and MDG mixture forms the surface active materials and the absorbed layer which efficiently decreases the friction losses and surface wear. Under the influence of such layer the Rebinder phe-nomenon could take place and also the formation of tribo-chemical layer is possible. The analysis of wear scars shows that different wear reduction mechanism is taking place when lubricating with RO and MDG mixture and with pure materials.