Visco-elastic properties of thin nylon films using multi-cycling nanoindentation

Time dependent behavior of thin nylon films is investigated by depth sensing nanoindentation. Different loading rates and holding times are applied in single indentation procedures to study the relaxation behavior of nylon resulting in a characteristic nonlinear displacement - time dependence. Several load-time functions of multi-cycling indentation are developed, such as constant load repetition and incremental load increase mode sometimes containing, holding segments. Hysteresis loops in multi-cycling nanoindentation quantify the visco-elastic energy of nylon films. The loading rate does not change the loop size if the maximum and minimum load of the cycle are the same. The unloading process has to be sufficiently large to allow the performance of the visco-elastic relaxation of the material.