Dynamic shock compaction of a ZrO2-RuO2 electronic nanocomposite: toward functionally graded materials

An electronic ZrO2-RuO2 nanocomposite was fabricated by dynamic compaction (DC) at 1.5 GPa resulting in a maximum relative density of 88% in the material. The DC process formed pristine elongated conical-shaped compacts 3 cm in length. The compacts retained their original nanometer-sized grains (~20 nm) of the original powder from which it was prepared, marking the densest RuO2-based nanocomposite to date. A change by a remarkable factor of 107 in electrical conductance was observed for two separate specimens, one processed by DC (δ = 1.1 × 10-4 S cm-1) and the other by conventional pressureless sintering (δ = 2.1 × 103 S cm-1) both obtained from the same starting nanopowder and thus with a similar concentration of conductor phase at 10 mol% RuO2.