An investigation of the ignition manner effects on combustion synthesis

The multi-point ignition of combustion synthesizing NiAl compound created by computational means has been analyzed in this article. Since the combustion reaction of Ni and Al is a low exothermic reaction, it has been found that the combustion front hardly propagates in order to complete the reaction. In this study, the reaction is subsequently ignited at different points or it is simultaneously ignited at several points to help the combustion front to propagate completely. The different positions of ignition are found to influence the temperature profiles and an increase in the number of ignition points is noted to increase the propagation velocity. In addition, the effect of a second ignition of the extinguished combustion reaction is also studied. It is noted that the position and time of the second ignition has dramatically influenced on the propagation velocity and combustion temperature, thus resulting in different grades of reactions. The extent of reacting for each double-ignition condition is calculated in order to generate the reacting maps. From the reacting maps generated in this study, the appropriate double-ignition condition can be chosen to synthesize homogeneous products. (C) 2003 Elsevier Science B.V. All rights reserved.