Energetic Nanocomposites as Burn Rate Catalyst for Composite Solid Propellants

Abstract

In the present study the effect of addition of Al/Fe2O3 based energetic nanocomposites (ENC) to non‐aluminized and aluminized propellants was investigated. Comparative study was carried out using n‐Fe2O3 as burn rate catalyst. Ferric oxide xerogel and Al/Fe2O3 ENC were synthesized by sol‐gel method. The dried xerogel was characterised by Scanning electron microscopy (SEM), Transmission electron microscopy (TEM), X‐ray diffraction (XRD) and X‐ray photoelectron spectroscopy (XPS). TEM and SEM images reveal presence of porous interconnected ferric oxide clusters of size 3–5 nm and intimate mixing of the ingredients at nanoscale in case of ENC. XRD analysis shows amorphous nature of the ferric oxide xerogel. Fe2O3 and FeO(OH) are the major constituents (>84 %) of the xerogel as confirmed by XPS analysis. Thermal analysis of the ENC indicates that the composition is energetic in nature. Sensitivity analysis was carried out to assess the safety of the ENC during propellant processing. The differential scanning calorimetry (DSC) results for propellant samples show that the Al/Fe2O3 ENC is a better catalyst for AP decomposition than n−Fe2O3. Burn rate studies of ENC catalyzed propellants with μ‐Al and with n‐Al were carried out using acoustic strand burner. The results indicate that ENCs can be promising catalysts for composite propellants.

Facile Fabrication of Cu‐doped Carbon Aerogels as Catalysts for the Thermal Decomposition of Ammonium Perchlorate

“…[4] In general, low decomposition temperature of AP lead to high combustion rate and thrust of composite solid propellants. [5][6][7][8] Therefore, the law of AP decomposition must be studied to improve propellant performance. Transition metals are usually used as AP thermal decomposition catalysts due to their simple preparation, good catalytic performance, and clear catalytic mechanism.…”

Ultra‐Fine Aluminium Characterization and its Agglomeration Features in Solid Propellant Combustion for Various Quenched Distance and Pressure

“…The compound analysis of agglomerates carried out using X‐ray diffraction (XRD) PANalytical diffractometer, which is quenched at four pressures viz., 2 MPa, 4 MPa, 6 MPa and 8 MPa, the results are represented in Figure . Based on the absorption effects, the relative intensity (ratio of aluminium peak/alumina peak) of an XRD pattern is directly proportional to the concentration of the component analysis . It can be observed from the Figure , that the alumina content in the agglomerates is consistently increasing with respect to pressure; this is mainly due to the progress in aluminium combustion from the propellant burning surface.…”

“…The resultant particle sizes of nano‐aluminium agglomerates is in the range of 1–5 μm, which indicates a higher rate of agglomeration than with micron‐sized aluminium, but these sizes are small relative to the agglomerates of latter . These studies are carried out by maintaining the distance between burning surface and constant quench distance.Hence, most of the studies reported the agglomerated aluminium or its combusted alumina particles whereas the studies on the effect of quenching/collecting distance from the burning surface and accordingly the influence of pressure are very limited, particularly with UFAL particles and the propensity of aluminium agglomerate combustion away from the propellant burning surface requires more advanced studies in order to estimate the agglomerate's fragmentation and combustion characteristics. Incidentally, these features will enable to increase the combustion efficiency and to avoid slag accumulation for further extent.…”

Oscillatory Pressure Effect on Mean Burning Rates of Solid Propellant Combustion at Low Frequency Conditions

“…Gupta et al [21] have made a comprehensive report on various methods available for measurements of the burning rate. Bagalkote et al [22] stated that the enhancement in mean burning rate was observed in composite propellants by adding nano energetic.…”