Abstract

Nanostructured Cu-Al_2O_3 composite powders were synthesized by thermochemical process. The synthesis procedures are 1) preparation of precursor powder by spray drying of solution made from water-soluble copper and aluminum nitrates, 2) air heat treatments to evaporate volatile components in the precursor powder and synthesis of nano-structured CuO + Al_2O_3, and 3) CuO reduction by hydrogen into pure Cu. The suggested procedures stimulated the formation of the gamma-Al_2O_3, and different alumina formation behaviors appeared with various heat treating temperatures. The mean particle size of the final Cu/Al_2O_3 composite powders produced was 20 nm, and the electrical conductivity and hardness in the hot-extruded bulk were competitive with Cu/Al_2O_3 composite by the conventional internal oxidation process.

• Keywords: Nanocomposites;Nanomaterials;Thermochemical process;Powder technology;Oxide dispersion strengthening;Electrode;