Determining modulus of nanowires using nanoindentation technique

This study demonstrates a finite element method for simulating the behavior of nanoindentation of copper nanowires and estimates their mechanical properties. The simulation results reveal that using well-known Oliver-Pharr theory, generally applied for materials with semi-infinite half-space, yields an underestimate of the elastic modulus of the wire materials. Moreover, the size of the indenter tip radius also influences the accuracy of the predicted elastic modulus. Such errors are mainly from the misestimate of contact area between an indenter and a specimen. They can be reduced directly from the observation of real contact area in the numerical modeling. The modified elastic modulus of the wires is very close to the bulk value.