Passivation of compact samples from pyrophoric iron nanopowders during their interaction with air

A study of various macrokinetic modes of interaction (self-ignition or combustion) of compact samples from non-passivated (pyrophoric) and passivated iron nanopowders with air has been carried out. Experiments have shown that the modes of interaction with air depend on the type of gaseous medium used (argon or air), in which the bottles with the samples were previously located, as well as on the duration of the exposure of the bottles in air. For the first time, the possibility of passivation of pressed samples from pyrophoric iron nanopowder was experimentally established when weighing bottles with samples in air. Various experimental methods have been used to study the dynamics of heating the sample and the effect of density nonuniformity along the length of the sample on it. It was found that the heating of pyrophoric samples is nonuniform, although it begins simultaneously over the entire surface of the sample.