Experimental study of the real time change in surface roughness during running-in for PEHL contacts

An optical system for the implementation of a new real time roughness measuring technique was incorporated to a two-disk machine. The change in surface roughness during the running-in stage of partial elastohydrodynamic lubricated wear tests was measured in a real time mode. The results were compared with the experimental data, which were measured, in a conventional manner, at discrete intervals of time by stopping the wear test. The apparent discrepancies reveal that the wear is enhanced by the stop/start actions. The effects of different initial roughness, sliding/rolling ratios and loading on the change in surface roughness during lubricated running-in tests were also studied with the current set up.