Thermal Property Measurements of Reactive Materials: The Macroscopic Behavior of a Nanocomposite

This study experimentally examined the thermal properties of reactive materials that are a composite of fuel and oxidizer particles. Three reactive materials were selected: aluminum (Al) with iron (III) oxide (Fe₂O₃); Al with Teflon (C₂F₄); and Al with titanium (IV) oxide (TiO₂). The experimental measurements were performed using a laser flash analyzer (LFA) and then compared with calculations based on weighted averages of each component in the composite. The effects of fuel particle size, oxidizer, and initial temperature on thermal properties were studied. Nanometric Al composites are more insulative than their micron-scale counterparts, exhibiting three times lower thermal conductivity in some cases. Increased overall contact resistance may be a key contributor to the reduction in thermal conductivity. The measured values deviated as high as 69% from weighted average estimates of thermal properties. These results suggest that factors not accounted for in weighted average estimates significantly influence the thermal properties of the matrix.