Hardness and modulus of elasticity of layers and solid materials

Nanoindentation of thin layers on glass.
© Fraunhofer IST
Nanoindentation enables the determination of hardness and modulus of elasticity a.o. of thin layers on glass.

Nanoindentation

Nanoindentation allows the local determination of hardness 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.

Microindentation

For thicker layers > 3 µm, microindentation can be used to determine Vickers, Martens or universal hardness. Microindentation is more robust and less costly. Both micro- and nanoindentation can be used to generate hardness-depth profiles on the cross-section (e.g. for nitrided samples, multilayer systems, etc.)

Nanoindentation with high lateral resolution

Series of nano-indents with CrN precipitation in nitrided steel. With hardness profile of the CrN particle in the steel matrix.
© Fraunhofer IST

Series of nanoindents through CrN precipitation in nitrided steel. With hardness profile of the CrN particle in the steel matrix.

Ultra-flat indexing

Ultraflache Indentierung in eine 400nm dünne Kupfer-Phtalocyanin-Farbstoffbeschichtung.
© Fraunhofer IST

Ultra-flat indentation into a 400nm copper phthalocyanine dye coating.

Depth-dependent hardness measurement

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.

Durch die Multipel-Partial-Unloading-Technik (mpu) kann mit einer einzigen Messung, die nur ca. eine Minute dauert, direkt eine tiefenabhängige Härtemessung durchgeführt werden. Dies ist das Verfahren der Wahl, um bei sehr dünnen Schichten zu entscheiden, ab welcher Tiefe ein Einfluss des Substrates sichtbar wird.
© Fraunhofer IST
Durch die Multipel-Partial-Unloading-Technik (mpu) kann mit einer einzigen Messung, die nur ca. eine Minute dauert, direkt eine tiefenabhängige Härtemessung durchgeführt werden. Dies ist das Verfahren der Wahl, um bei sehr dünnen Schichten zu entscheiden, ab welcher Tiefe ein Einfluss des Substrates sichtbar wird.
© Fraunhofer IST

Vickers hardness: Hardness depth profile of nitrided layers

Hardness depth profile of 3 different types of steel that were nitrided under identical conditions (520°C, 16h, 80%N).
© Fraunhofer IST

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”.

 

Reference project

Prognosis tool for plasma nitriding processes

Creep and relaxation tests on polymers

Creep and relaxation tests on polymers
© Fraunhofer IST

Determination of creep or relaxation modulus for a time interval of 1-1000 seconds, suitable for viscoelastic materials (paints, polymers).

Self-healing of polymers

Self-healing of polymers
© Fraunhofer IST

Self-healing of paints/polymers after damage. The graph shows the decrease in depth of damage over a period of three days.

Further information

 

Publication

Kirsten Ingolf Schiffmann

Nanoindentation creep and stress relaxation tests of polycarbonate: Analysis of viscoelastic properties by different rheological models.

In: International Journal of Materials Research 97 (2006), 9, p. 1199-1211