Nanoscratch behaviour, structure and nanoindentation of multilayer TiN/CrN coatings

The nanoscratch behaviour of TiN/CrN nanolaminates has been investigated in the present study. The critical load (LcL) during the loading process characterises the fracture resistance of the coating, whereas that during unloading (LcU), characterises the adhesion strength between the coating and the substrate. For all coatings, the nanoscratch profiles indicate three distinct regimes: elastic deformation, elastic?plastic deformation and delamination with material removal. Multilayer coatings show significantly higher critical loads than monolayer coatings. SEM characterisation indicates the cracking mechanisms are different for monolayer and multilayer coatings explaining why the multilayer coatings withstand higher critical loads.