Tribological Behavior of Organic Anti-Wear and Friction Reducing Additive of ZDDP under Sliding Condition: Synergism and Antagonism Effect

The effect of eichhornia crassipes carbon nanotubes (EC-CNTs) as additives in both base mineral oil (MOO) and vegetable rapeseed oil (ROO) alone and also together with ZDDP additive under sliding condition was studied. The investigation shows that both on individual and in combine state enhanced tribological properties. The coefficient of friction reduction was 40 % and 37.5 % for EC-CNT inclusion against ROO and MOO respectively under 80 N. The study revealed that enough tribofilm were generated thereby separating the two surfaces leading to low COF. In the case of wear effect, combination of the two additives gives substantial reduction of 65.5 % and 70.2 % against MOO and ROO respectively. The study shows that more reduction was obtained with RO + EC-CNT + ZDDP than the other. The use of two additives in combine lubrication shows synergistic effect, however, observed antagonistic effect if MO + EC-CNT + ZDDP is used for long period of time. The study further revealed that EC-CNT does more of anti-wear service while ZDDP improves friction reducing effect as well as anti-wear.