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 some metal-oxide systems have been investigated in this article. The experimental results show that the highly exothermic nature of a reaction is only a requisite condition for initiating combustion; whether the combustion takes place or not depends on the dynamic state of the reaction system during milling. The influence of the crystalline structures of the reactants on the ignition of combustion reactions instigated by high-energy ball milling is not clear. The ignition starting points of combustive reactions trigged by 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 not visible for the reduction of CuO with metals instigated by ball milling. It is suggested that probably the occurrence of a reduction reaction induced by mechanical force depends mainly on the disintegration of the oxide. The mechanical properties and the type of atomic bond of the reactants also have an effect on the initiation of a combustion reaction during ball milling. (C) 2001 Published by Elsevier Science B.V.