抄録
Bulk nanocrystalline nickel dispersed homogenously with nano-scale hard WO_3 particles has been successfully synthesized by a novel synthesis using electrodeposition. In this synthesis, ionized W_4^<2-> molecules in an electrolyte were transformed into WO_3 particles and embedded into a nanocrystalline nickel matrix during electrodeposition by controlling the pH and potential of the electrode. The effect of the presence of nano-size oxide dispersions on the strength and thermal stability of nanocrystalline structures was demonstrated. This is indeed a new class of bulk nanocrystalline metals in that nano-scale second-phase particles are not reactive precipitate from the solute-supersaturated matrix, but are stable oxide particles resistant to the so-called Ostwald ripening. In this regard, future optimization of this synthesis have potential to realize nanocrystalline metals with record-high strength and thermal stability, superior to their precipitates- or solutes-stabilized counterparts.
