Fatigue and deformation of HVOF sprayed WC–Co coatings and hard chrome plating

A challenge facing the finishing industry is to replace chrome plating since this technology has negative environmental and health effects. In the case of tungsten carbide and chrome carbide coatings, HVOF and detonation spray technologies have proven to be cleaner and more effective. In this paper, the results of a comparative investigation involve a detailed analysis of fatigue and deformation of two groups of AISI 4340 steel specimens. One group sprayed with HVOF WC–Co coating and the other group was plated with hard chrome. Rotating beam fatigue tests were performed on the coated and uncoated specimens. Optical and SEM microscopy were used to evaluate the fracture morphology. The fatigue life distributions of coated AISI 4340 steel specimens demonstrated that the HVOF coated specimens exhibited higher fatigue lives compared to the uncoated specimens.