Combustion Reactions of Some “Metal-Oxide” Systems under Conditions of Zero and Applied Magnetic Fields: Thermal Imaging Experiments

Abstract

The effect of an external magnetic field of 0.2 T on the self-propagating high temperature syntheses (SHS) of a mixture of first row transition metals and their oxides was studied by using a very sensitive thermal imaging method involving an IR-camera and software developed by MIKRON Instrument Co., Inc. (M9100 Pyrovision Series – Imaging Pyrometer). For the basic conversion of first row transition metals to their corresponding oxide, there was no observable difference in propagation behavior between applied and zero field reactions. However the average wave velocity for the iron system showed a significantly greater value when the SHS was conducted under conditions of an applied field. This enabled accurate monitoring of the combustion process in particular propagation velocity, maximum temperature, cooling rates, synthesis wave width and pathway. Several interesting phenomena, such as hole formation in the pellet and combustion wave segmentation were detected in some systems.