Advances in Thin Film Nanoindentation
A new model of thin film indentation that accounted for an apparent discontinuity in elastic strain transfer at the film/substrate interface was developed. Finite element analysis suggested that numerical values of strain were not directly continuous across the interface; the values in the film were higher when a soft film was deposited on a hard substrate. The new model was constructed based on this discontinuity; whereby, separate weighting factors were applied to account for the influence of the substrate in strain developed in the film and vice-versa. By comparing the model to experimental data from thirteen different amorphous thin film materials on a silicon substrate, constants in each weighting factor were found to have physical significance in being numerically similar to the bulk scale Poisson’s ratios of the materials involved. When employing these material properties in the new model it was found to provide an improved match to the experimental data over the existing Doerner and Nix and Gao models. Finally, the model was found to be capable of assessing the Young’s modulus of thin films that do not exhibit a flat region as long as the bulk Poisson’s ratio is known.
KeywordsTitanium Nickel Quartz Dioxide Carbide
Unable to display preview. Download preview PDF.
- 16.Oliver WC (1986) Progress in the Development of a Mechanical Properties Microprobe. MRS Bull. 11:15-19.Google Scholar
- 18.Pharr GM (1998) Measurement of mechanical properties by ultra-low load indentation. Mat. Sci. & Eng. A:151-159.Google Scholar
- 23.Buckle H (1973) The Science of Hardness Testing and its Research Applications. ASM, Metals Park, Ohio.Google Scholar
- 38.Shackelford JF, Alexander W (2001) CRC Materials Science and Engineering Handbook. CRC Press, Boca Ratan, Florida.Google Scholar
- 41.Engdahl G (2000) Handbook of Giant Magnetostrictive Materials. Academic Press, San Diego, CA.Google Scholar