Experimental-numerical approach for characterization of mechanical properties of thin electrochemically deposited chromium and copper films

A hybrid experimental-numerical approach, which combines microindentation experiments (where we measure the diagonal of the residual imprint after unloading) and numerical simulations by means of the finite-element method has been developed. The investigated materials in the present work are electrochemically deposited on brass substrates chromium and copper films with known thickness and unknown mechanical properties. Mechanical properties of the brass (CuZn36) substrate are known. Vickers' microindentation experiments were carried out on the films and as a result the experimental load-displacement curves were obtained. After that the process of microindentation was modelled numerically by means of the finite-element method. Numerically obtained load-displacement curves were compared with the experimental curves. The results show good coincidence between numerical and experimental curves. Additionally it was realized nanoindentation experiment of thin copper film and these two methods (nanoindentation experiment and hybrid experimental-numerical method which combines experiment of microindentation and numerical simulations) for determination of mechanival properties of thin copper films were compared. Results obtained by means of the afore-mentioned two methods almost coincide but the second method is cheaper and gives more information about material properties of the film than the first method. It is shown that the second method is preferable to determine the mechanical properties of thin metal films.