Boron (B) is regarded as a premier candidate fuel in high-energy composites due to its higher reaction enthalpies. However, boron suffers from sluggish oxidation and energy release kinetics as a result of its low melting oxide shell. Post-melting, the non-volatile liquid oxide layer acts as a diffusion barrier to the oxidizing species and restricts their access to the boron core, thereby inhibiting oxidation and energy release.
Prof. Zachariah and his team have developed an innovative magnesium/boron (Mg/B) based composite that offers a thermodynamically and kinetically viable source of highly reactive gas-phase Mg that acts as an etchant for the oxide shell of boron. The developed composite creates a pristine and accessible fuel surface for the reaction. Further reactions are facilitated by the thinning of the oxide shell. Together, these serve to enhance the combustion of boron.
Schematic illustration of the reactivity enhancement of Boron
Graph showing the burn characteristics of B/CuO nanoenergetic composites. Mg/B/CuO composites show significant enhancement in burn times and pressurization over B/CuO composites.
The significant benefits and aspects of this Mg/B-based composites relative to B-based composites are:
Applications that use energetic materials such as propellants, solid fuels, thermites, etc.