TEM studies of the wear of TiAlN/CrN superlattice coatings

The role of surface deformation in the wear of TiAlN/CrN multilayer coatings was investigated. The multilayer coatings were deposited on a M2 speed steel substrate by physical vapour deposition (PVD) in a four target Hauzer HTC1000-ABS coating machine. The worn surface was examined by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Plastic deformation led to microcracking, providing a mechanism for subsequent wear through surface delamination. The loss of the multilayer structure in the outer 40 nm coating is consistent in the 500-600 °C temperature range.