Effect of Heating Rate of the Original ASD-4 Powder and the ASD-4 Powder Modified by the V2O5 Oxide on the Phase Composition of Oxidation Products

Resumo

X-ray diffraction with the help of synchrotron radiation is used to analyze a sequence of phase formation in the oxidation of original and modified Al powders in the case of heating in oxidizing gaseous media with rates of 10 and 100 K/min. It is established that an increase in the heating rate of the modified ASD-4 powder leads to an active growth of metastable phase (θ- and δ′-Al₂O₃) of aluminum oxide except for the γ-Al₂O₃ phase. Assumptions about the forms of existence of vanadium in the interaction products are given. It is shown that diffusion limitations in the core—shell system (Al-Al₂O₃) can be removed under the action of an oxidizing aluminum particle on physicochemical processes at interphase boundaries.