Effect of Particle Size and Magnesium Doping on Fe/CuO Pyrotechnic Composition Combustion

Abstract

This study explores the combustion behavior of Fe/CuO thermite systems by systematically evaluating the effects of iron particle size, Fe content, porosity, and magnesium (Mg) doping. Thermite pellets were fabricated using three Fe particle size ranges (0–20 µm, 20–40 µm, and 40–80 µm) with varying Fe contents (20–70 wt%), compacted under constant pressure. Combustion performance was evaluated under a fixed single ignition condition. The addition of 2.5 wt% Mg enhanced reactivity and ensured complete and sustained combustion, particularly in compositions with coarse particles or high Fe content.

Beyond burning rate analysis, pellet porosity was measured prior to ignition, and mass changes (loss or gain) were quantified by comparing pellet mass before and after combustion. These data provided insights into the material’s conversion efficiency and the influence of ambient atmospheric oxygen on post-combustion mass variation. Combustion repeatability was verified through triplicate testing, with low standard deviations confirming experimental consistency.

The powders were characterized by using Scanning Electron Microscopy (SEM) to assess particle morphology and agglomeration, while Energy Dispersive Spectroscopy (EDS) was used to confirm elemental composition and detect potential surface oxidation or impurities. SEM/EDS observations revealed strong morphological differences between the particle size classes, directly affecting packing density and reaction uniformity.

In conclusion, combining fine Fe particles, a balanced Fe/CuO ratio, and 2.5% Mg doping produced fast, reliable, and reproducible combustion, offering promising potential for advanced thermite-based energetic applications. The resulting data set captures the complex interplay between composition, structure, and ignition behavior in Fe/CuO thermites. It serves as a robust experimental foundation for pyrotechnic laboratories and modelers working on numerical simulation, reaction front propagation, and kinetic parameter extraction in thermite systems.