Enhancement of self-sustaining reaction Cu3Si phase formation starting from mechanically activated powders

Mechanical high-energy ball milling of an 3Cu+Si elemental powders mixture was used to activate a self-sustaining combustion reaction or so-called self-sustaining high-temperature synthesis (SHS) to form the copper silicide phase, a reaction for which the thermodynamic criterion proposed by Munir for self-propagation reaction is not favorable. A complete characterization of the end-products was performed with X-ray diffraction analysis and scanning electron microscopy. Thermal and structural information describing the combustion front initiated by heating up a sample to 180°C in a Cu/Si system is communicated. This paper clearly shows that the mechanically activated self-sustaining high-temperature synthesis process produces a pure Cu3Si compound in spite of the limitation imposed by the thermodynamic criterion. In addition, it seems that the reactivity of Cu3Si elaborated from the mechanically activated SHS process towards CuCl is greater than the reactivity of Cu3Si reference powder. This difference is mainly due to the crystallite size.