Tribology of vegetal oils as base for eco-friendly nano additivated lubricants

This paper presents an analysis based on experimental data for pointing out the behavior of rapeseed oil when it is additivated with a modifier of friction and wear, the nano hexagonal Boron nitride. All tests are done on a four-ball machine, in mild regime. Test parameters were sliding velocity (0.38 m/s, 0.53 m/s, 0.69 m/s, corresponding to the spindle rotational speed of the four-ball machine of 1000 rpm, 1400 rpm, 1800 rpm (±10 rpm),), force (100 N – 300 N), test duration 1 h. There were calculated the average friction coefficient during the test and the average wear scar diameter (WSD) for each test. The same test parameters were done twice and the values in this paper are the average of these two tests. Wear was discussed for the same velocity range, in terms of WSD, but for comparing tests with different sliding velocity (implicitly, different sliding distances), there was used the wear rate of the wear scar diameter. The results on wear parameters, using additivated rapeseed oil, do not show spectacular results for the parameters tested in this study, but underline the “insensitivity” of the lubricants to the variation of the test regime (especially with respect to sliding speed), which is desirable for certain applications.