Effect of Notch Geometry on the Plastic Behavior of Cu-Ag Composites

Understanding failure in conductive composites is critical for the design of reliable electrical components. Using strain mapping, we studied the effect of notch geometry on mechanical properties and the mechanisms of notch-related plastic deformation. Our study clearly revealed notch strengthening in Cu-Ag nanocomposites. In all notched samples, we found highly localized necking bands between pairs of notches. Under tension, these bands developed into ellipse loops. Within the bands, deformation strain was much higher than the average strain over a large neighboring area. The plasticity of necking bands depended on notch tip radii. In samples whose notch tip radius was ∼ 3.81 mm, the localized strain within necking bands reached as high as 50%. In samples with sharper notches (∼0.20 mm), necking plasticity still attained 18% before failure. The results of this study provide unique insights into the endurance and performance of high-strength composites.