(491d) Effect of Mechanical Activation on Reaction Kinetics In Gasless Heterogeneous Systems

In this
work, we investigated the effects of mechanical activation (MA) on
the kinetics of several gasless reaction systems, including
nickel-aluminum, hafnium-aluminum, iron oxide--titanium, and others.
Reaction kinetics were primarily studied by differential thermal
analysis (DTA), while the microstructures of the investigated
reaction mixtures were characterized by scanning electron microscopy
(SEM), electron dispersive spectroscopy (EDS), and x-ray diffraction
analyses (XRD). It was demonstrated that under certain conditions,
MA can significantly (>10 times) change the activation energy in
such gasless high energy systems. This effect, in turn, influences
the self-ignition temperature, as well as the velocity of the
reaction wave propagation in these systems. Based on established
correlations between the kinetic parameters and microstructural
characteristics of heterogeneous reaction media, an explanation of
the observed effect is suggested.