Influence of heating rate on oxidation of the powder ASD-4 modified by V2O5
- Mr. Danil ESELEVICH
Aluminum powders, due to their high specific heat of combustion, are widely used in explosive, the production of high-energy combustible mixtures and solid fuels for rocket engines. To solve the problem of high protective properties of oxide film on the surface of metal particles, in recent years much attention is paid to the development of methods for the activation of Al powders and the optimization of their combustion processes. In this work shows the results of studying the oxidation characteristics of the initial and modified Al powder with vanadium pentoxide at a heating rate of 30 and 100 K / min, because exothermic heterogeneous reactions are characterized by a strong dependence on the thermal regime. The vanadium content is about 0.8 wt. %. Carried out a complex study of the oxidation of a modified aluminum powder in air and in a gas mixture flow of 20%O2 + 80%N2 up to 1473 K by methods TG, DSC, X-ray diffraction using a synchrotron radiation sourc. It was found that an increase in the heating rate of the modified ASD-4 powder leads to an active growth of metastable phases of aluminum oxide (θ and δ'-Al2O3) passing phase γ-Al2O3. The heating rate of modified aluminum affects the phase composition of the oxidation products, where the basis of the oxidation mechanism is the effect of V2O5 on the increase in the rate of delivery of the oxidant (oxygen) to the metal surface.