Environmentally Friendly Boron-Based Pyrotechnic Delays: An Additive Manufacturing Approach

Pyrotechnic time delays are reactive systems that burn for a desired period of time at a specified rate and are commonly used in military applications such as grenades and hand-held signals. Typically, they are manufactured by pressing the reactive powder into a metal housing. This rigid design inherently limits configurability, and they have had reliability issues. Additionally, there has been advocacy for environmentally friendly pyrotechnic ignition delays, by removal of barium chromate (BaCrO₄). This study has two distinct objectives. First, determine the viability of two possible replacements, strontium molybdate (SrMoO₄) and barium molybdate (BaMoO₄), for the harmful component, BaCrO₄, in the traditional T-10 delay. This includes combustion characteristics such as burning rate, combustion temperature, and gas generation. Furthermore, thermal characteristics are determined through differential scanning calorimetry (DSC), and combustion products are analyzed with X-ray diffraction (XRD). Second, by using a novel approach, these reactive delay systems are integrated into printable ink formulations and deposited onto soapstone substrates. This demonstrates a high degree of configurability and an effort toward a universal delay.