Development of an experimental method to evaluate tensile strength of notched nanowires

Abstract

In order to clarify the influence of stress concentration on the tensile strength of nanowire, we developed an experimental method to perform a tensile test for nanowire under field emission scanning electron microscope (FESEM) observation and evaluated mechanical properties of two types of aluminum nanowire specimens: one was a smooth nanowire and the other was a notched nanowire. A notch was introduced by using focused helium ion beam. As a result of the tensile test with the developed experimental method, the relationship between load and displacement, and the FESEM image during the test was acquired. Young's modulus of the notched specimen was equal to that of the smooth specimen. On the other hand, the values of yield stress, ultimate tensile strength, and total elongation of the notched specimen were, respectively, less than those of the smooth specimen, indicating the sensitivity to the presence of a notch. Fracture location of the notched specimen was at a notch. These results suggest that stress concentration dominants fracture.