Design of Experiment Analysis of Plain ZDDP Oil in the Presence of FeF₃ Using Two Different Rotational Speeds and Extreme Contact Load

The purpose of this study was to investigate the effect of cooling contact surface temperature of the test cylinder when a rise in contact temperature over 100 degree C occurs during boundary lubrication tribological testing. The Hertzian contact pressure in a ball on cylinder tests will be optimized with respect to the contact temperature using Design of Experiment (DOE) software. Several boundary lubrication tests were conducted to study the behavior of 0.1 P% (phosphorus percentage) plain ZDDP oil in the presence of 0.4% FeF₃ under two different rotational speeds (lower stage of 100 rpm for the first 5000 revolutions and higher stage of 700 rpm until failure or 100000 revolutions whichever comes first). The one rotational speed of 700 rpm until failure will be compared to the two speed stages under a contact cooling surface temperature and different contact loads (2.77GPa–3.8Gpa Hertzian contact pressures). The two different speed stages indicate better performance under an extreme contact load and a lower contact surface temperature; whereas higher contact surface temperature and lower load are needed for the one speed stage of 700 rpm cycle.