High-Temperature Mg-Al-KNO ₃ -Viton Pyrotechnic Compositions: Binder-Controlled Coating and Pellet-Based Ignition Performance

Reliable ignition of turbojet engines at high altitude remains a critical challenge because reduced pressure and temperature impair fuel atomization and evaporation while also increasing flame kernel instability, thereby reducing ignition reliability and flame stabilization. Existing studies predominantly focus on material-level combustion behavior or laboratory-scale evaluations, often lacking validation under engine-relevant conditions. In this study, a system-level approach is presented by integrating material optimization, surface-coverage-based coating considerations, pellet-based configuration, and controlled processing to improve pyrotechnic ignition performance. Mg-KNO3-Al-Viton compositions were systematically investigated, yielding a maximum flame temperature of 3369.91 K for Mg-KNO3-Viton (32.5/62.5/5 wt%) and up to ~3760 K with aluminum addition (27/60/8/5 wt%). The binder content (5 wt% Viton) was selected based on a theoretical surface coverage analysis using the calculated specific surface area of the powder mixture, providing adequate particle coverage and improved particle dispersion. The prepared compositions were compacted into pellets to achieve consistent geometry and reproducible ignition performance. Experimental results show sustained combustion exceeding 7 s. The findings suggest that aluminum addition alone is insufficient to achieve high-performance ignition, and that ignition behavior is governed by the coupled interaction of composition, multi-metal effects, and binder-related interfacial processes. The proposed approach establishes a formulation-to-system-level framework for improving ignition reliability under conditions where atomization-driven mechanisms are limited, offering a practical and scalable strategy for advanced pyrotechnic ignition systems.