Behaviour of shot peening combined with WC-Co HVOF coating under complex fretting wear and fretting fatigue loading conditions

This study investigated the fretting and fretting fatigue performance of tungsten carbide–cobalt (WC–Co) HVOF spray coating systems. Fretting wear and fretting fatigue tests of specimens with shot peening and WC–Co coatings on 30NiCrMo substrates were conducted. The WC-Co coating presents very good wear resistance and decreases by more than 9 times the energy wear coefficient (α) under fretting conditions. The tested coating reduces crack nucleation under both fretting and fretting fatigue studied situations. Finally the crack arrest conditions are evaluated by the combined fretting and fretting fatigue investigation. It is shown and explained how and why this combined surface treatment (shot peening and WC–Co) presents a very good compromise against wear and cracking fretting damage.