Combustion characteristics of mechanically alloyed ultrafine grained Al-Mg powders

The combustion characteristics which include ignition time and burning time in environments having different temperatures, of mechanically alloyed ultrafine-grained Al-Mg powders was investigated. The burning rate depends on particle size, and it takes place in several stages which are vapor/diffusional and surface oxidation stages, and an addition of a metal with lower ignition temperature facilitates particle combustion. X-ray diffraction (XRD) patterns were recorded from the as-milled powders of all the compositions to determine if any structural occurreds ocured in the powders after milling. The XRD patterns from the Al-20 at.% Mg showed the presence of a single phase with an fcc structure indicating that a supersaturated solid solution of Mg in Al was obtained at room temperature. The results show that a supersaturated solid solution of Al in Mg coexisted with the γ-Al12Mg17 phase.