Effect of start-up schemes and amplitude of tangential motion on friction behavior in fretting point contact

The friction coefficient is an important factor in fretting fatigue. The frictional behavior of quenched and tempered steel 34CrNiMo6 was studied in smooth fretting point contact with measurements at partial and gross slip conditions. The effect of the start-up scheme is studied by altering the way the displacement amplitude is developed to the target value. This only has a minor effect on the maximum friction coefficient but it does alter the frictional behavior. The friction coefficient increases as tangential displacement amplitude is increased and it has a maximum value of 1.5–1.6 at the transition to gross sliding.

Research highlights
► The following highlights were collected from the results:
► The friction coefficient increases as displacement amplitude is increased in partial slip condition.
► The friction coefficient has a maximum value of 1.5–1.6 at transition to gross slip.
► The effect of the start-up scheme on frictional behavior is limited to the first 500×103 load cycles.
► High friction coefficient and evidence of material transfer indicates strong adhesion.