Structure and Reactivity of Mechanoactivated Mg (Al)/MoO3 Nanocomposites

X-ray diffraction and thermal analyses, microscopy, and specific surface area measurements are used to study the formation, structure, and reactivity of mechanoactivated Mg/MoO3 and Al/MoO3 nanocomposites during slow heating (10 degrees C/min). The optimal mechanoactivation dose is determined. The mechanoactivated Mg/MoO3 composite is a dense mixture of two nanosized components with a contact surface of similar to 8 m(2)/g (upper estimate). The area of the contact surface between the components of the Al/MoO3 composite is less than 2 m(2)/g, with the sample consisting of micron-sized aluminum flakes coated with nanoparticles oxide nanoparticles. When heated, the Mg/MoO3 system explodes, with the temperature of explosion being determined by the heating conditions. The minimum temperature of conversion is similar to 250 degrees C, close to the temperature of autoignition of fuel-air mixtures promoted by these additives. The Al/MoO3 system is characterized by a phased progress of the reaction in the temperature range of 200 to 1000 degrees C. The reasons for the differences in the reactivity of the mixtures are discussed.