Influence of Surface Roughness on Traction and Scuffing Performance of Lubricated Contacts for Aerospace and Automotive Gearing

In this study, a two-disk test set-up was employed to investigate the impact of surface roughness on the performance of lubricated contacts. In an attempt to simulate contacts from automotive transmissions and rotorcraft gearboxes, roller specimens made of a typical automotive gear steel (AISI 5120) and a common rotorcraft gear steel (AISI 9310) were paired with 80W90 and MIL-PRF23699 lubricants, respectively. The specimens were subjected to various operating conditions to measure their traction and scuffing outcome (i) axially ground, (ii) chemically polished isotropic surfaces, and (iii) highly polished mirror-like surfaces.