Fine aluminum powders are prepared by decomposing alane-adducts in organic solvents under an inert atmosphere to provide highly uniform particles selectably sized from about 65 nm to about 500 nm and believed particularly effective as fuels and additives, in pyrotechnics, and in energetic materials including composites, super thermite, and other explosives. Effective adduct species are trialkyl amines and tetramethylethylenediamine, ethers and other aromatic amines being believed effective. Effective production is obtained at atmospheric pressure and at temperatures as low as 50.degree. C. with xylene solvent. Increased production rate is achieved at higher temperatures. Toluene, dioxane, and tetramethylethylenediamine were also effective solvents. Aliphatic solvents and other aromatic and polar solvents are believed effective. Titanium catalyst was provided as a halide, amide, and alkoxide; and it is believed that the corresponding compounds of zirconium, hafnium, vanadium, niobium, and tantalum are effective as catalysts. Particle size was controlled by varying catalyst concentration and by varying the concentration of an adducting species, as by adding an amine to the solution or using an amine as the solvent. It is believed that particle size is controllable by varying the catalyst, concentration of the reactants, polarity of the solvent, reaction temperature, and the stage and rate at which the solution is brought to this temperature. The product powder is passivated in the reaction vessel by exposing the solution to air before product separation or by controlling the admission of air to the separated, dried powder.