Energy storage in aluminum nanopowder in stress-strain state of crystal lattice

When transforming metals into nanodispersed state nanopowders acquire new properties, including the storage of energy by nonopowders. The increasing interest to aluminum powders and nanopowders is caused by their application as a high-energy additive in rocket fuels and pyrotechnic mixtures. Thus, the investigation of energy storage in Al nanopowder is of great importance. Besides, it is not easy to determine the amount of stored energy in Al nanopowder. The authors have used the aluminum nanopowder obtained by electrical explosion of aluminum wire in argon, using UDP-4D installation developed in Tomsk Polytechnic University. The main aim of the study is to asses experimentally the value of energy, stored in the form of stress-strain state of the crystal lattice of Al nanopowder and to compare the obtained value to a general value of stored energy. The methods used in the study are the X-Ray diffraction, differential thermal analysis. It was ascertained that the crystal lattice is in stressed state in air-passivated electroexplosive aluminum nanopowder. The modified Lorenz function was used as a profile function; crystalline microdistortions, calculated by the approximation technique, amount to 8,66 x 10[-4]. The value of energy, stored in the stress-strain state of the crystal lattice of electroexplosive aluminum nanopowder, is 0,385 J/g, while the value of stored energy, determined by means of differential thermal analysis, is 348 J/g. Thus, the most feasible mechanism of storing significant energy in aluminum nanopowder is the formation of more energy-saturated structures in solid (the formation of a double electric layer with pseudocapacity during passivation).