Fretting wear behavior of CuNiAl against 42CrMo4 under different lubrication conditions

•Influence of lubrications on torsional fretting was investigated under flat contact.•The friction and wear increased with the deteriorating of lubrication conditions.•The corrosion products in seawater lubrication showed friction and wear reducing effect.•It was a mixture of liquid and solid lubrication under liquid lubrication condition.

Fretting wear behavior of CuNiAl against 42CrMo4 was investigated under different lubrication conditions with the flat on flat contact configuration. In oil, filtered water and artificial seawater, it was under a mixture of liquid lubrication and third body solid lubrication, so the friction torque was lower than that under dry fretting. Wear was the slightest in oil and the most serious under dry fretting. The corrosion products under seawater lubrication presented a friction and wear reducing effect. The wear mechanisms depended on the lubrications. In oil, they were dominated by abrasive wear and plastic deformation; under the two water lubrications, they were mainly cracks, delamination and abrasion; under dry fretting, they were mainly abrasive wear and oxidation wear.