Experimental and modeling investigation on the self-propagating combustion behavior of Al-MoO3 reactive multilayer films

Abstract

In order to probe the self-propagating combustion behavior of aluminum/molybdenum trioxide (Al/MoO3) reactive multilayer films (RMFs), RMFs with varied modulation periods and widths were deposited by the magnetron sputtering method on a glass substrate. Differential scanning calorimetry revealed that thermal reaction was in the solid-solid phase at thin modulation periods (50 nm and 150 nm) and in the liquid-solid phase at the microscale (1500 nm). Furthermore, since X-ray diffraction analysis demonstrated the presence of aluminum oxide, the hot spot and pre-oxidation theory of the interface in Al/MoO3 RMFs allowed logical explanation of the thermal reaction feature. The RMFs achieved stable self-propagating combustion with 50 nm–150 nm modulation periods excited by a laser pulse but not at 300 nm–1500 nm. The average stable combustion velocity was 6 m s−1 at the 150 nm modulation period and reached 10 m s−1 for 50 nm. The two-way analysis of variance demonstrated that the effect of the width on combustion velocity was not significant. Thus, we constructed a one-dimensional (1D) combustion velocity model based on heat transfer theory combing experimental data. The model explored the relationship between the stable combustion velocity and the modulation period.