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Rapidly solidified Mg based alloys are of interest for industrial applications as a structural material and for hydrogen storage. Mg-Cu-Rare Earth alloys have shown high glass forming ability; full amorphous structure with thickness of mm size can be obtained within these systems. However, their brittle behavior limits their industrial applications. In the present work, the Al effect in substitution of Cu in the Mg 65 Cu 25 MM 10 (at%, MM: mischmetal) was studied. Samples up to 15at% Al were prepared by splat cooling and their microstructure, stability and mechanical properties were characterised. The crystallization temperature increases with the Al addition; the amorphous phase with different Al content has a Young's modulus of ~55GPa; the microhardness increases with the Al content in the amorphous and crystallized samples and the fracture of the alloy containing 10at% Al showed ductile vein patterns characteristics of ductile metallic glasses. The partial Cu substitution by Al can improve the stability and mechanical properties of the amorphous Mg 65 Cu 25 MM 10 alloy.

Since coupling between the combustor oscillations and the unsteady combustion of the fuel spray drives combustion instabilities in liquid fueled combustors, "disruption" of this coupling by changing the fuel spray properties offers an approach for controlling these instabilities. This paper describes an experimental study that employed such an approach to control combustion instabilities in a liquid ftieled (n-heptane) combustor that used a novel internally mixed liquid fuel injector with a vaporizing element. This injector forms a fuel spray by mixing liquid fuel and a secondary air in a liquid/air mixing tube. The generated spray impinges upon a hot vaporizer plate, on top, as it flows towards the combustor, resulting in partial evaporation of the fuel in the spray. The resulting spray then enters the combustor through a slit between the vaporizer plate and the conical flame holder. Combustion occurs when the spray mixes with the primary air stream that enters the combustor through an annular region between the combustor wall and conical flame holder. The dependence of the characteristics of the instabilities upon the operating conditions of the injector (and, thus, spray properties) and acoustic properties of the setup were studied. The spray properties were varied by changing the flow rate of the secondary air stream into the injector's mixing tube and the combustor's acoustics were varied by changing the length of the primary air supply tube. The characteristics of the flow and combustion processes were studied from measured pressure and radicals radiation data. The results clearly showed that combustion instabilities could be controlled by changing the fuel spray properties and that the amount of attained damping depends on the frequency. In addition, emissions measurements show that the concentrations of CO, SO 2 and unburned hydrocarbons decreased as the size of the fuel droplets in the spray decreased. Interestingly, NO levels decreased as the amplitude of the instability increased.

In this paper we report the effect of alloying elements on hydrogen storage properties of meltspun Mg-based alloys. The base alloys Mg 90 Si 10 , Mg 90 Cu 10 , Mg 65 Cu 35 (at%) were studied. We also investigated the effect of rare earths (using MM: mischmetal) alloys showed an amorphous and partially amorphous structure respectively. At 350˚C all the alloys had a crystalline structure during the hydrogen absorption-desorption tests. It was observed that Si and Cu in the binaries alloys hindered completely the activation of the hydrogen absorption. The partial substitution of Cu by MM or Al allowed activation. The combined substitution of Cu by MM and Al showed the best results with the fastest absorption and desorption kinetics, which suggests that this combination can be used for new Mg-alloys to improve hydrogen storage properties.