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 (ωCuO = 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 (ωCuO = 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 (ωCuO = 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.