SHS Synthesis of Boron Particles with Increased Surface Area

Due to their high heat of combustion, amorphous boron particles are an interesting fuel for pyrotechnic and solid rocket applications. A commonly used procedure to improve reactivity of metal particles in energetic applications, is to reduce the particle size to nanometer-sized particles. However, metal nanoparticles introduce new challenges and risks, such as health risk on handling, a higher content of unreactive material due to the passivation layer and a higher processing effort e.g., due to agglomerations. To avoid all these problems but to take advantage of the good properties of boron, we applied the moderated SHS reaction process to produce nanostructured, micrometer-sized boron particles. The nanostructured particles have an increased surface area, which increases the reactivity and the total conversion rapidly and makes the produced boron particles interesting for energetic applications. In this work we present a self-propagating high-temperature synthesis method (SHS) to produce nano-structured boron particles [3][4]. We examined possible parameters that influence the surface, as well as the characterization of the resulting boron particles. Finally, we used the particles in a model application and compare the burning behavior to mixtures containing commercially available amorphous boron particles with particle sizes in the micrometer range.