Fatigue and Deformations of HVOF Sprayed WC-Co Coatings vs. Hard Chrome Plating

Environmental problems of hard chrome plating are raising its cost and shrinking availability. HVOF and Detonation spray technologies for application of tungsten carbide and chrome carbide based coatings have proved to be cleaner and more effective than chrome plating. In this paper, the results of fatigue tests for WC-17Co coating deposited onto AISI 4340 steel by HVOF are compared to those for hard chrome plating. The fatigue life distributions as a function of the probability of failure for the coated AISI 4340 steel specimens showed that the HVOF coated specimens exhibited extraordinarily higher fatigue lives compared to the uncoated specimens whereas the hard-chrome-plated imparted fatigue strength degradation to the AISI 4340 steel.