Combustion Characteristics of Coated Nano Aluminum in Composite Propellants

Abstract

The effects of coated nano-sized aluminum (Al) powder (n-Al) and micron-sized Al powder (g-Al) in propellants on the burning rate and pressure exponent have been investigated. The results show that the burning rates of propellants increase as the n-Al content increases, but the burning rate pressure exponents tend to decrease. Compared with propellant containing -Al, the increments of burning rates of propellants containing n-Al powder reduce gradually with increase in the pressure because of the differences of the combustion characteristics and ignition performances of n-Al powder and g-Al powder. Single short distance photograph, scanning electron microscopy, x-ray fluorescence analysis were used to characterise the flame image, combustion phenomena, the quenched surface image, and surface elements. A substantial difference in combustion characteristics of n-Al powder has been found in comparison with -Al powder. In addition, oxygen-bomb combustion heat, ignition temperature, and recovery ratio of residues were measured.Keywords: Nanotechnology, nanostructured materials, aluminium powder, micron-sized aluminium powder, combustion, nano-sized aluminium powder, composite propellantsRevised 10 May 2006 . INTRODUCTIONNanotechnology is a frontal crossing subject developed gradually since late 1980's. Nanostructured materials have been used in the area of defence, military, space, and aviation. It is well known that solid propellants are the fuels of the solid rocket motors. If nano-sized materials are added to the solid propellants, the performance of propellants dramatically enhances. For fabricating the higher burning rate and the higher energy propellants, nano-sized materials have tremendous latent energy. The new generation of missiles and propellants for space flight application requires higher performance, so this provides widespread perspectives for the application of nanostructured materials. Thus, the Defence Science Journal, Vol. 56, No. 4, October 2006, pp. 543-550 2006, DESIDOC 543 study of nano-sized materials as a component of propellants is considered important.In 1994, Daizo Fukuma 1 used the 1.5 m superfine ammonium perchlorate (AP), 100 nm superfine Al and silver wire into the hydroxy-terminated polybutadiene HTPB-based propellants, and 150 mm/s super-burning rate was achieved. American company MACH I produced a kind of nanocat superfine iron oxide (SFIO) with particle size of 3 nm. The burning rate of HTPB-based propellants increases from 22.10 mm/s to 27.69 mm/ s and the pressure exponent decreases from 0.5 to 0.46 with a mass addition of 10 per cent SFIO. Moreover, the safety and the stabilised performance of SFIO are far better than conventional Fe 2 O 3 , catocene and other ferrocene derivative 2 .

Combustion Characteristics of an Al/H2O Mixture with Polyoxyethylene

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Assembly of metals and nanoparticles into novel nanocomposite superstructures

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Effect of Metal Nanopowders on the Performance of Solid Rocket Propellants: A Review

“…The results show that the burning rates of propellants increase as nAl content increases, but the pressure exponents over the pressure range of 3–7 MPa decrease. Compared with propellant containing mAl, the increments of burning rates of propellants containing nAl powder reduce gradually with increasing pressure due to the combustion characteristics and ignition performance differences of nAl and mAl powder [ 82 ]. Meantime, the combustion features of 85% bimodal HTPB/AP/Al composite propellant with 0.75% by mass of nAl into wet-mixed boron at varying ratios of Al to boron (4:1, 2:3, 1:4) were performed between 3.45 and 15.51 MPa in a constant volume pressure vessel using nichrome wire ignition and compared to that of formulations with dry magnesium-boron (MgB) and mAl@B at the same mass loadings.…”