Chlorination of aluminium-copper alloys

The chlorination of Al-Cu alloys is investigated by thermogravimetry, X-ray diffraction, scanning electron microscopy, energy dispersive spectroscopy, and energy dispersive X-ray fluorescence, between 200 and 500 degrees C. The starting temperature for the chlorination of selected alloys is determined. Results indicate that the reactivity of the alloys is different from that of the pure metals. Analysis of the reaction products reveals that there are interactions between the different chlorides formed. These interactions lead to an enhancement in the copper chlorides volatilization and the formation of well-developed crystals of CuCl2 instead of the mixture of CuCl2 and CuCl that is obtained in the chlorination of pure copper. A schematic diagram that describes the chlorination mechanisms for the pure metals and AlCu alloys is presented. (C) 2007 Elsevier B.V. All rights reserved.