Ignition and Combustion Characteristics of B/NC/CuO Thermite Microparticles

Abstract

To improve the combustion stability and ignition performance of thermite, B/NC/CuO micro particles were prepared from boron (B), nano copper oxide (CuO), and nitrocellulose (NC) as an energetic binder through the electrospray technique. The burning rate dependency on boron content, ambient temperature, and pressure was estimated by compressing B/NC/CuO micro particles into columns. Scanning electron microscopy results show that the sizes of these particles mostly lie in the range of 3–4 μm. The particles are ignitable and burn consistently with minor variations in the conditions: B content (8.3–17%), ambient temperature (−50–55 °C), and ambient pressure (0.02–0.1 MPa). The optimum formula was observed for micro particles with 11 wt% B content. Compared with the ball milling sample, the standard deviation of the burning rate of the electrosprayed sample was reduced by 32%. Combustion is barely affected by ambient pressure. Between −50 °C to 55 °C, the burning rate of B/NC/CuO increases by 14.16% from an initial rate of 13.35 mm⋅s−1. In addition, the laser ignition energy required for B/NC/CuO microparticles was also reduced from 70 to 45 mJ.

Keywords

• boron
• thermite
• burning rate
• combustion performance