MECHANICAL PROPERTY CHARACTERIZATION OF THIN-FILMS USING SPHERICAL TIPPED INDENTERS

Ultra- or nano-indentation of thin films provides, in principal, a rel atively simple approach to quantify the mechanical properties of thin films. Considerable emphasis has been placed on the ability of pointed indenters to measure such properties. An alternative indentation appr oach that offers some advantages is the use of very small spherical ti pped indenters. The latter provide a more tractable solution to the co ntact problem. In addition it is possible to follow the elastic to pla stic or brittle behaviour during indentation more clearly than with po inted indenters. Greater insight to the actual behaviour of indented m aterials may be obtained by complementary microstructural observations of the indented region. Finally the role of substrate and interface a dhesion on the force-displacement behaviour of thin films indented wit h spherical tipped indenters is schematically summarized.