Hydrogen-induced change of oxidation combustion characteristics of Al2Mg alloy

Abstract

The effects of solid-state hydrogen introduction on the oxidation combustion property and mechanism of Al 2 Mg alloy were investigated by means of thermal analysis, X-ray diffraction, scanning electron microscopy and energy dispersive spectrum. It was found that the starting combustion temperature of hydrogenated Al 2 Mg alloy is lowered by about 150 °C as compared with pristine Al 2 Mg alloy, due to its distinct phase composition of MgH 2 + Al as well as loose, porous and refined particle characteristics. The first-stage oxidation for the Al 2 Mg alloy hydride can be ascribed to the dehydrogenation of MgH 2 to form Mg followed by the reaction of Mg with oxygen to form MgO, which is entirely different from the oxidation mechanism of Al 2 Mg alloy. During the second-stage oxidation, MgAl 2 O 4 , γ-Al 2 O 3 and α-Al 2 O 3 were formed for both Al 2 Mg alloy and its hydride. However, almost no AlN can be generated for the Al 2 Mg alloy hydride with respect to Al 2 Mg alloy. • Solid-state hydrogen is introduced into Al 2 Mg alloy combustion agent. • The starting combustion temperature is reduced by 150 °C. • MgH 2 dehydrogenates and then reacts with oxygen during the first-stage oxidation. • Almost no AlN forms during the second-stage oxidation.