Running-in of aluminum/steel contacts under starved lubrication: Part II. Effects on scuffing

In this second part, the two aspects of run-in, i.e. surface smoothing and film formation, analyzed in Part I for different run-in procedures, are discussed in relation to the observed scuffing resistance of run-in components. Scuffing tests are run at different sliding velocities and under starved lubrication conditions. For the roughness values tested, run-in procedures could be determined so as to significantly increase the scuffing resistance of aluminum/steel contacts. The higher scuffing resistance is related primarily to film formation. Under high velocity test conditions, however, the destruction rate of protective surface films is such as to provide little, if any, scuffing protection. At the higher velocities, surface conformity (smoothing) seems to be very important.