Fatigue of Thin Silver Films Investigated by Dynamic Microbeam Deflection

Abstract

AbstractThe fatigue behavior of bilayer microbeams consisting of thin Ag films on an SiO2 substrate was investigated. The beams were cyclically deflected using a commercial nanoindentation instrument, which is capable of precise positioning of indentations. The dynamic beam stiffness is monitored continuously throughout the whole experiment. Silver was chosen as a model material for fcc metals. For large strains and/or strain amplitudes the beam stiffness decreased significantly during the fatigue tests, which is related to damage formation, as cracks and extrusions were found after the experiment. In fatigue tests at lower strains and the same number of cycles no significant stiffness change was observed. In this case only extrusions but no cracks occurred.