On the analysis of the stress-strain behaviour of thin metal films on substrates using nanoindentation

Norbert Huber (1) , Edouard Tyulyukovskiy (1) , Oliver Kraft (2, 3)

1 IMF II
2 IMF II
3 IZBS - Institut für Zuverlässigkeit von Bauteilen und Systemen

Based on load-depth data, as measured by nanoindentation with a Berkovich tip, stress-strain curves of metal films (Al, Cu, and Ti) with thickness of 1 to 4 µm were determined. This so-called inverse analysis was carried out using a neural network approach. The method uses hardness and stiffness data from indentation into the film/substrate composite with a depth range of 10 to 200% of the film thickness, and yields the material parameters describing a non-linear elastic-plastic stress-strain curve of the Armstrong-Frederick type. It is shown that the method can only be applied if a sufficient difference in film and substrate hardness is present. For all films investigated, a significant dependence of the film strength on its microstructure, as characterized by focused ion beam microscopy, has been found.

Mots clés: Physical Sciences

Norbert Huber, Edouard Tyulyukovskiy, Oliver Kraft. On the analysis of the stress-strain behaviour of thin metal films on substrates using nanoindentation. Philosophical Magazine, 2006, 86 (33-35), pp.5505-5519. ⟨10.1080/14786430600615033⟩. ⟨hal-00513668⟩