Characterization of Cu-Al₂O₃ nano-scale composites synthesized by in situ reduction

Abstract

The copper-alumina system is reported to have an excellent combination of properties that are essentially dependent on their microstructure, which in turn, will vary according to the preparation method. In this work, the synthesis of the Cu-Al₂O₃ (5 wt.%) nano-scale composites were carried out by in situ reduction of a powder mixture consisting of CuO and Al₂O₃, previously obtained through a chemical route. The procedure imparts special features to the product in terms of microstructure. TEM bright field and centered dark field imaging have shown well-developed copper crystals surrounded by a fine dispersion of Al₂O₃nano-scale particles, which are in the order of 10 nm. Copper crystals in the order of 50 nm are dispersed and exhibit twinning despite their small size. Current investigation is being developed towards the determination of particle size distribution through HRTEM.