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The processes of oxidation of electroexplosive ultradisperse powders (UDP) of aluminum by water in the range of temperatures 50—75°C are studied by the method of continuous recording of gas release. It is shown that the electroexplosive UDP of aluminum are capable to be actively oxidized by water with the formation of oxide—hydroxide phases and hydrogen release already upon moderate heating. At temperatures higher than 75°C the oxidation occurs like a degenerate thermal explosion. The macrokinetic parameters of the oxidation of aluminum UDP are determined. The data obtained can be used to assess the fire hazard of UDP in the presence of moisture and analyze the combustion of aluminum UDP in the composition of energy materials.

Abstract: The combustion of mixtures of an ultrafine electroexplosive aluminum powder with water thickened by a 3% polyacrylamide additive is investigated. The reaction in a combustion regime is accompanied by the formation of a superheated foamy layer in gel-like water. The incompleteness of aluminum burnout in a stoichiometric mixture, which is explained by boiling-out of water from the reaction zone, is shown. The maximum combustion temperatures are determined in various conditions by means of thermocouple measurements and combustion-product composition calculations. The possibility of producing ultrafine or monolithic corundum as a reaction product is shown.

Abstract: The kinetic features of oxidation of ultradisperse powders of aluminum, copper, iron, molybdenum, zinc, and tin, which were obtained by the method of electric explosion of conductors, are studied by the nonisothermal thermogravimetric method. It is shown that the process of oxidation has a multistage character; however, at the initial stage, the products do not form a continuous film and the oxidation of all the metals occurs by a linear law. The temperatures of onset of oxidation with a noticeable rate are determined by the temperatures of desorption of the gas components of ultradisperse powers. The self-ignition temperatures of the powders are determined by the method of differential thermographic analysis. In addition, it is shown that these temperatures depend on the thermophysical properties of a metal and the kinetics of the initial stage of oxidation.

Abstract: The synthesis of molybdenum disulfide in a combustion wave, from mixtures of sulfur with ultradisperse molybdenum powder obtained by electrical explosion of wires, is investigated. Experimental data are give on the combustion rate and temperature and the degree of conversion to the final product as a function of the pressure and component ratio. It is shown that the process corresponds to a parabolic law with an activation energy of 80 J/mole and be described by an elementary model of combustion of the second kind. Optimal conditions of synthesis with a yield of up to 99% are determined.