Effect of heating rate of the original ASD-4 powder and the ASD-4 powder modified by the $\mathrm{V}_2\mathrm{O}_5$ oxide on the phase composition of oxidation products

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 $\mathrm{Al}$ 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 ($\theta$- и $\delta$'-$\mathrm{Al}_2\mathrm{O}_3$) of aluminum oxide except for the $\gamma$-$\mathrm{Al}_2\mathrm{O}_3$ phase. There are assumptions on the forms of existence of vanadium in the interaction products. It is shown that diffusion limitations in the core – shell system ($\mathrm{Al}$–$\mathrm{Al}_2\mathrm{O}_3$) can be removed under the action of an oxidizing aluminum particle on physicochemical processes at interphase boundaries.