Influence of contact stress on rolling contact fatigue of composite ceramic coatings plasma sprayed on a steel roller

The influence of contact stress on rolling contact fatigue performance of plasma sprayed Al2O3-40 wt% TiO2 composite ceramic coating was investigated using a double-roll test machine under pure rolling contact condition. The shear stresses within the coating were analyzed with the three-dimensional finite element method. Three modes of failures, i.e., surface abrasion, spalling, and delamination, were observed during this investigation. The failure mechanisms of surface abrasion, spalling, and delamination were discussed in detail. The initiation and propagation of fatigue cracks were mainly caused by the shear stress, which were highly influenced by the contact stress.