Monolayer TiAlN and multilayer TiAlN/CrN PVD coatings as surface modifiers to mitigate fretting fatigue of AISI P20 steel

In many sense, the role of a corrosion film and a surface coating in fatigue crack initiation is similar. The performance of the TiAlN and TiAlN/CrN PVD coatings in resisting fretting fatigue failure of the AISI P20 steel was investigated. A significant increase in fretting fatigue life was observed; up to 210% and 193% when clamped at 5.6 kN and 12.6 kN, respectively for the TiAlN coated specimens, and up to 798% and 762% when clamped at 5.6 kN and 12.6 kN, respectively for the multilayer TiAlN/CrN coated specimens. Both PVD coatings showed a beneficial compressive residual stress and substantial increases in its resistance to plastic deformation (H3/E2) as well as surface hardness compared to the uncoated AISI P20 tool steel.