Title: Effect of porosity on the indentation behaviour of nanoporous alumina films

Authors: M.S. Bobji, Prashant Pendyala, Preeti Gupta, Pranav Kalode

Addresses: Department of Mechanical Engineering, Indian Institute of Science, Bangalore-560012, India. ' Department of Mechanical Engineering, Indian Institute of Science, Bangalore-560012, India. ' Department of Mechanical Engineering, Indian Institute of Science, Bangalore-560012, India. ' Department of Mechanical Engineering, Indian Institute of Science, Bangalore-560012, India

Abstract: Anodising aluminium in an acid electrolyte results in a porous alumina film. The pores are uniformly distributed and their structure can be controlled by varying the anodising parameters. In this study, the pore structure of the anodic alumina films is varied systematically by varying the anodising time and a subsequent pore widening chemical etch. The indentation behaviour of the resulting film is studied using a depth sensing nanoindenter. The hardness of the films was found to be decreasing with decreasing solid area fraction. Understanding the deformation behaviour of nanoporous alumina would help tailoring the mechanical properties by tuning the geometry.

Keywords: nanoporous alumina; NPA; nanoindentation; surface mechanical properties; hardness; porosity; indentation behaviour; alumina films; aluminium; pore structure; deformation; nanotechnology.

DOI: 10.1504/IJSURFSE.2011.039990

International Journal of Surface Science and Engineering, 2011 Vol.5 No.1, pp.51 - 62

Published online: 14 Oct 2014 *

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