Assisted self-sustaining combustion reaction in the Fe–Si system: Mechanical and chemical activation

This work presents original investigations carried out to improve the activated self-propagating high-temperature synthesis (SHS) process in the Fe–Si system: different ignition modes are tested (volume heating as opposed to a local ignition source), and the use of additive is considered in order to enhance the SHS type reactivity in the Fe–Si system. When 20 wt.% of KNO3 is added to the reactive mixture, the fast (>20 mm s−1), stable and self-sustaining combustion reaction produces a very fine FeSi + α-FeSi2 structure. Infrared thermography (IR) as well as post-mortem analysis (SEM, EDXS, XRD) was used to understand the mechanism behind the chemical activation process when KNO3 was used as an additive.