Effect of Nb content on the strength of Cu-Nb filamentary microcomposites

The yield strength of Cu-Nb filamentary microcomposites was predicted as a function of Nb content by modifying the barrier strengthening model. To predict the variation of the yield strength with Nb content, the interfilamentary spacing was calculated as a function of Nb content on the basis of the assumption that Nb filaments are distributed regularly along the sides of triangular unit cells. The yield stress can be described as the sum of the substructural strengthening component and the filament boundary strengthening term. The good agreement between the prediction and the experimental data suggests that the strength increase in Cu-Nb filamentary microcomposites with increasing Nb content results mostly from increasing the volume fraction of Nb filaments, which act as barriers to plastic flow.