Tribological Behavior of Lamellar Molybdenum Trioxide as a Lubricant Additive.

In this study, the tribological behavior of lamellar MoO₃ as a lubricant additive was investigated under different concentrations, particle sizes, normal loads, velocity, and temperature. The friction and wear tests were performed using a tribometer and with a reciprocating motion. The results indicate that the friction-reducing ability and antiwear property of the base oil can be improved effectively with the addition of lamellar MoO₃. The 0.5 wt % and 0.1 wt % concentrations of MoO₃ yield the best antifriction and antiwear effects, respectively. The maximum friction and wear reduction is 19.8% and 55.9%, compared with that of the base oil. It is also found the MoO₃ additive can decrease the friction considerably under a high velocity and normal load, and increase the working temperature. The smaller the size of MoO₃, the better the friction-reducing effect the lamellar MoO₃ shows. The friction-reducing and antiwear mechanisms of lamellar MoO₃ were discussed.