Experimental quantities of metastable Al-Mg solid solutions (Mg contents 10-50%) have been recently prepared using mechanical alloying. Such solid solutions are predicted to be a new type of metallic high energy density materials in which specific phase changes are pre-programmed to occur at a desired temperature and trigger ignition of accelerate combustion rate of the fuel. Preliminary tests have indeed shown that mechanical alloys have significantly reduced ignition temperatures and higher combustion rates as compared to the pure aluminum. The ignition temperatures and combustion rates were shown to depend on the alloy composition, crystal lattice parameter, and crystallite size. It is proposed that these new materials can be used in a new generation of explosives and incendiary devices with the explosion parameters tailored precisely to defeat specific targets. An experimental program aimed at the feasibility demonstration of this hypothesis is described. Samples of mechanical alloys of the aluminum and boron based compounds will be prepared and tested. A constant volume explosion technique is is chosen to characterize performance of the new materials. Analytical instrumentation, e.g., an electron microscope, an x-ray diffractometer, a bomb calorimeter, etc., will be used to characterize structures and compositions of mechanical alloys and their combustion products.An opportunity identifiied in this proposed research is to explore the feasibility of the new mechanically alloyed metallic powders with varied compositions and nanocrystallite sizes as an additive to explosive formulations that would enable one to control the blast parameters in a wide range. If successful, such materials can be used in a variety of explosive and incendiary devices and enable one to precisely adjust the produced blast parameters to defeat specific targets. In addition, admixtures of trace amounts of the easily detectable elements could be added to mechanical alloys, such elements released in a blast would produce the readily observable signatures required for the damage assessment. During Phase II, special technology will be designed to produce those materials in commercial volumes for weapon systems.
