Scuffing evaluation of fully formulated environmentally acceptable lubricant using barrel-on-disc technique

Scuffing evaluation is challenging due to the catastrophic nature of this failure mode. In this paper, a new scuffing test method was designed for evaluating the scuffing capacity of fully formulated industrial oils. A barrel-on-disc technique was employed in which the specimens are moving in opposite direction under rolling–sliding conditions. The maximum Hertzian pressure could reach up to 3.06 GPa, and the test plan was a combination of increasing-sliding speed and increasing-load steps. Furthermore, the tribofilm evolution was captured using Spacer Layer Interferometry Method (SLIM), and the correlation of tribofilm and micro-scuffing/scuffing was presented. Results revealed the difference between the scuffing capacity of Environmentally Acceptable Lubricants and the Mineral oils which had the same scuffing capacity in their datasheet.