Investigation of material properties of thin copper films through finite element modelling of microindentation test

Abstract

Technology processes of thin metal films deposition are entailed with changes in material’s microstructure. As a result, deposited films often are characterized with material properties, which are different from these of the original bulk material. Determination of these material characteristics is of big importance for practice. In the present work the material properties of thin bright copper film with known depth were investigated. The film was deposited electrochemically over substratum composed of metallurgic brass alloy (CuZn36). Based on the results from microindentation test the load–displacement curve is obtained after the indenter is unloaded and the imprint diameter is measured. Consequently the process of indentation was modelled numerically. The numerical simulation is based on the finite element model of the indentation process. As a result of the simulation the load–displacement curve was obtained numerically for a certain set of material parameters. The trial–error approach is applied to find most appropriate set which fit the experimental load–displacement curve. At the end results, which were obtained through numerical simulation give good coincidence with the experiment. Therefore the proposed method can be successfully applied for identification of material parameters of the accepted model. The proposed trial–error approach is appropriate for investigation of thin films with known thickness, deposited on a substrate with known material characteristics.