Fretting fatigue and friction of quenched and tempered steel in dry contact with aluminum bronze

• Fretting fatigue measurements were made with bronze–steel Hertzian point contact.
• The friction coefficient was measured to be around unity in gross sliding.
• Fretting wear damage leads to material transfer.
• Fatigue cracks nucleate next to wear debris.

Bronze–steel contacts are common in machinery where the loading might give rise to fretting conditions. The flat surfaces of the quenched and tempered steel (QT) specimens were fretted with aluminum bronze spheres in partial slip and gross sliding conditions. The dry friction coefficient was around unity in gross sliding. Material transfer occurred from bronze pad to the QT-specimen and cracks initiated at these locations. Fretting map comparisons with QT–QT fretting tests showed that aluminum bronze–QT contact produces fatigue cracks with lower values in terms of displacement amplitude, tangential force amplitude and Findley cracking risk.