Microindentation depth profiling of selected hard coatings

A comparative analysis of microindentation results is presented on selected commercially available as well as experimental hard coatings. Using a Fischerscope H100C device the load between 1 mN and 1000 mN was applied. Depth profiling was done in three ways: indirectly by applying progressively increasing loads, low-load measurements on right-angle cross-section (for thicker films only) and low-load measurements on a low-angle cross-section. Various nitride-based coatings were analyzed, both single-layer and multilayer. The best results were obtained on right-angle cross-section, but this method is limited on relatively thick films of several μm. For thinner films as well as multilayers with a period of several tens of μm, low-angle cross-section technique yields useful results provided the load is not greater than a few mN. Measurements perpendicularly to the surface, using different loads, provided only a qualitative depth profile.