To improve electrical and mechanical properties of electrodes for contact w
elding. the Cu-Al2O3 nano composite powders were developed by thermo-chemic
al process. This method uses water-soluble copper and aluminium nitrates as
the starting material and consists of four steps: the preparation of nitra
tes water solution, spray drying of this solution to prepare initial powder
with subsequent salt decomposition heat treatment in air atmosphere to pre
pare the oxide powder containing CuO and Al2O3 and a final hydrogen reducti
on of copper oxide to copper. Suggested method has shown a good result to a
chieve the agglomerated copper powder with about 20nm size of aluminium oxi
de clusters and a homogenous distribution of oxide particles. (C) 2001 Acta
Materialia Inc. Published by Elsevier Science Ltd. All rights reserved.