Preparation and combustion properties of laminated sticks of B–CuO and B–Bi2O3

To explore the composite process of B–CuO and B–Bi₂O₃ two-component laminated sticks, obtain the corresponding sticks with good printing effect, and explore the energy release behavior. In this study, boron, copper oxide, and bismuth trioxide powders were dispersed in the dispersed phase (DMF) using F₂₆₀₂ as a binder, and the construction of two-component B–CuO, B–Bi₂O₃, three-component micro-composite, and three-component macro-composite sticks were realized with the help of double nozzle direct ink writing (DIW) technique respectively. The resulting sticks were ignited by a nichrome wire energized with a direct current, and a high-speed camera system was used to record the combustion behavior of the sticks, mark the flame position, and calculate the rate of ignition. The results showed that the B–CuO stick burning rate (42.11 mm·s⁻¹) was much higher than that of B–Bi₂O₃ (17.84 mm·s⁻¹). The formulation with the highest CuO content (ω_CuO = 58.7%) in the microscale composite of the sticks also had the fastest burning rate of 60.59 mm·s⁻¹, as the CuO content decreased (ω_CuO = 43.5%, 29.3%), its burning rate decreased to 34.78 mm·s⁻¹, 37.97 mm·s⁻¹. The stick with the highest copper oxide content (ω_CuO = 60%) also possessed the highest burning rate (48.84 mm·s⁻¹) in the macro-composite sticks, and the burning rates of the macro-composite sticks with component spacing of 0.1 mm, 0.2 mm, and 0.5 mm were 43.34 mm·s⁻¹, 48.84 mm·s⁻¹, and 40.76 mm·s⁻¹.