Hostname: page-component-586b7cd67f-dlnhk Total loading time: 0 Render date: 2024-11-27T01:07:41.262Z Has data issue: false hasContentIssue false

Nanoindentation induced crack morphologies in nanostructured hard thin films

Published online by Cambridge University Press:  11 February 2011

A. Karimi
Affiliation:
Faculty of Basic Science, Swiss Federal Institute of Technology (EPFL), CH-1015 Lausanne
A. E. Santana
Affiliation:
Faculty of Basic Science, Swiss Federal Institute of Technology (EPFL), CH-1015 Lausanne
T. Cselle
Affiliation:
Platit AG, CH-2540 Grenchen, Switzerland
M. Morstein
Affiliation:
Platit AG, CH-2540 Grenchen, Switzerland
Get access

Abstract

Crack formation in hard thin films and the influence of nanostructuring on nucleation and propagation of different crack types were studied using TiAlSiN-based multicomponent nitrides. Thin films of about 2 μm thickness were deposited onto tungsten carbide-cobalt substrates using cathodic arc PVD method. By rotation of samples and changing deposition parameters and chemical composition of target materials, various nanostructured thin films were obtained including: nanocomposite films made of nanocrystallites about 10–30 nm, chemically modulated layers with the bilayer thickness at the range of 10 nm, iso-structured TiAlN/TiAlSiN multilayers with variable bilayer thickness, and finally monolithic single layer with columnar structures of different size. Depth sensing nanoindentation was used to measure hardness and modulus of thin films and to activate several failure modes in order to provide an estimation of the fracture toughness and interfacial fracture energies. Morphology of cracks mainly consist of successive microcracks nucleated at the contact edge periodically under stretching tensile stress upon displacement of indenter. These cracks are almost straight, parallel to each other, regularly distributed at the contact site in fine structure films. They appear discontinuous and irregular in coarse columnar monolithic and in multilyers with larger bilayer periods. The annular cracks appear at greater loads due to tensile peaks caused by bending stresses generated from the substrate depression and coating deflection. These can be accompanied by the interface fracture and delamination. The radial cracks emanating from the corner of indenter appear in high stress films and extend to the neighbouring zones of the contact area. In addition to geometrical cracks, nanoscale cracks frequently appear around the contact area leading to the formation of small discontinuities on the load-displacement curves.

Type
Research Article
Copyright
Copyright © Materials Research Society 2003

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

1. Veprek, S., J. Vac. Sci. Technol. A 17(5), 2401 – 2420 (1999).Google Scholar
2. Prengel, H.G., Jindal, P.C., Wendt, K.H. et al., Surf. Coat. Technol 139, 25 – 34 (2001).Google Scholar
3. Holubar, P., Jilek, M., Sima, M., Surf. Coat. Technol 133–134, 25 – 34 (2000).Google Scholar
4. Karimi, A., Bethmont, D., Wang, Y., Mat. Res. Soc. Symp. Proc. Vol. 695, 335340(2002)Google Scholar
5. Artz, E., Acta Mater. Vol. 46, No. 16, 56115626 (1988).Google Scholar
6. Fu, H.H., Beson, D.J., Meyers, M.A., Acta Mater. 49, 2567 – 2582 (2001).Google Scholar
7. Geisler, H., Schweitz, K.O., Chevallier, J., Bottiger, J., Samwer, K., Phil. Mag. A 79(2), 485 (1999)Google Scholar
8. Koehler, J.S., Phys. Rev. B 2, 547 (1970).Google Scholar
9. Clemence, B.M., Kung, H., Barnett, S.A., MRS – Bulletin 24(2), 20 – 25 (1999).Google Scholar
10. Andeson, P.M., Li, C.. Nanostruct. Mater. 5, 349 (1995).Google Scholar
11. Veprek, S., J. Vac. Sci. Technol. A17(5), 2402420 (1999).Google Scholar
12. Yashar, Ph.C., Sproul, W.D., Vacuum 55, 179190 (1999).Google Scholar
13. Holleck, H., Schier, V., Surf. Coat. Technol. 76–77, 328 – 336 (1995).Google Scholar
14. Luo, Q., Rainforth, W.R., Müunz, W.D., Scripta Mater. 45, 399 – 404 (2001).Google Scholar
15. Andersen, K.N., Bienk, E.J., et al, J. Bottiger, Surf. Coat. Technol. 123, 219226 (2000).Google Scholar
16. Pharr, G.M., Oliver, W.C., Cook, R.F. et al, J. Mat. Res. Vol. 7, No. 4, 961971 (1992).Google Scholar