HTPB bonded pyro-organic spectral flares

Recent missiles equipped with modern seeker technology are able to distinguish between target and decoy flares evaluating spectroscopic emission. So, future flares must be adapted to the thermal and spectral emissivity of the platform to be protected. One way to achieve such spectral flares consists in the application of so-called pyro-organic flares. The idea is to combine hydrocarbon combustion to meet spectral requirements and pyrotechnic mixtures to increase the radiation intensity. In this study HTPB bonded samples with AP as oxidizer and different pyrotechnical mixtures were prepared and tested with regard to potential use as a spectral flare. Two thermite mixtures, and a titanium/graphite mixture compared to pure titanium and a titanium carbide mixture were used. The combustion experiments were performed once in free atmosphere at normal pressure, and even at reduced pressure levels. It can be shown that all investigated samples have good combustion properties as well as very good spectral properties even at reduced pressure. The oxidation of the binder and post combustion with ambient air of the pyrotechnic reaction products lead to a second reaction phase resulting in a favorable β/α-ratio. Most promising mixtures for further investigations are with thermite as pyrotechnic component.