Nanoindentation allows the local determination of hardness (nanohardness) and Young's modulus on ultrathin films (> 300 nm) with a lateral resolution in the micrometer range and thus also enables local hardness measurements or hardness mapping on inhomogeneous samples. In addition, creep or relaxation tests can be used to characterize the viscoelastic properties of polymer layers or the self-healing behavior of scratches in coatings.
For thicker layers in the range > 3 µm, microindentation can be used to determine Vickers, Martens or universal hardness. Microindentation is more robust and less costly than nanoindentation. Both microindentation and nanoindentation can be used to generate hardness-depth profiles on the cross-section (e.g. for nitrided samples, multilayer systems, etc.)
Series of nanoindents through CrN precipitation in nitrided steel. With hardness profile of the CrN particle in the steel matrix.
Ultra-flat indentation into a 400nm copper phthalocyanine dye coating.
Using the multiple partial unloading technique (mpu), a depth-dependent hardness measurement can be taken directly with a single measurement, taking only approx. 1 min. This is the method of choice for deciding at what depth substrate influence becomes visible in the case of very thin layers.
Hardness depth profile of three different types of steel that were nitrided under identical conditions (520° C, 16 hours, 80 %N). The investigations were carried out as part of the project ”Prognosis tool for plasma nitriding processes for the edge-layer treatment of tools and components”.
Determination of creep or relaxation modulus for a time interval of 1-1000 seconds, suitable for viscoelastic materials (e.g. paints, polymers).
Self-healing of paints and polymers after damage. The graph shows the decrease in depth of damage over a period of three days.