Doping effects on mechanical properties of nanoporous gold systems

We report in this article, the Dysprosium doping effects on microstructure and mechanical properties of nanoporous metallic gold, synthesized by electrochemical dealloying of Ag₇₀Au₃₀ and Ag₇₀Au₂₉Dy₁ alloys. It is shown that these dealloyed nanoporous metallic materials exhibit the mean ligament diameter in a length scale of 5–10 nm. The variation of ligament diameter in pure and Dysprosium doped nanoporous Au with annealing temperature influences their mechanical properties. Higher microhardness value has been obtained around 10 nm ligament diameter on both pure and Dysprosium doped nanoporous gold. The maximum values of Vickers hardness H_V obtained from the analysis of indentation diagonals with applied load are close to the H_V value reported for bulk gold. Since the nanoporous metallic materials behave in a way like compressible sponge materials, we used the well-known density scaling equation for the determination of ligament yield strength of pure and Dysprosium doped nanoporous gold with ligament diameter. The results obtained have been finally compared with literature reports.