Effect of WC-Co-Cr coating on fatigue behaviour of AISI 1045 steel without and with heat treatment

The effects of WC-10Co-4Cr high velocity oxygen fuel (HVOF) coatings on the fatigue lives of AISI 1045 steel shaft-bending specimens without and with heat treatment have been investigated. X-ray Diffraction (XRD) analysis was used to determine the residual stresses distributions of the HVOF coated layer. Scanning Electron Microscopy (SEM) was used to evaluate the fracture morphology. The results indicate that the fatigue strength of the specimens increased with HVOF coating. The application of HVOF coating results in a greater increase in fatigue strength for heat-treated specimens compared to non-heat-treated specimens. This can be attributed to the higher magnitude of compressive residual stress in the HVOF coatings on heat-treated specimens. The high elastic modulus and compressive residual stress of the coating layer contribute to the improved fatigue life observed in the HVOF-coated specimens compared to the uncoated specimens.