Effect of material characteristics on the ignition of the combustion reactions induced by ball milling

The combustive reduction reactions induced by high-energy ball milling in s ome metal-oxide systems have been investigated in this article. The experim ental results show that the highly exothermic nature of a reaction is only a requisite condition for initiating combustion; whether the combustion tak es place or not depends on the dynamic state of the reaction system during milling. The influence of the crystalline structures of the reactants on th e ignition of combustion reactions instigated by high-energy ball milling i s not clear. The ignition starting points of combustive reactions trigged b y heating or ball milling have nearly the same linear uptrend with the rise of melting temperatures for the reaction systems of Al/CuO, but this is no t visible for the reduction of CuO with metals instigated by ball milling. It is suggested that probably the occurrence of a reduction reaction induce d by mechanical force depends mainly on the disintegration of the oxide. Th e mechanical properties and the type of atomic bond of the reactants also h ave an effect on the initiation of a combustion reaction during ball millin g. (C) 2001 Published by Elsevier Science B.V.