Recent advances on the preparation and combustion performances of boron-based alloy fuels

Boron-based alloy fuels are expected to replace boron to improve ignition performance and combustion efficiency of boron-based fuel-rich propellant. A large amount of work has been published on this topic. This literature review focuses on the preparation methods and combustion performances of boron-based alloy fuels include binary alloy fuels and ternary alloy fuels. The metals can be used to prepare boron-based alloy fuels include Mg, Al, Ti, Fe, etc. The preparation techniques include mechanical blending, high energy ball milling, arrested reactive milling, sonochemical synthesis and wet chemistry deposition. In terms of gravimetric energy density, (Al/2B)(AlB2) prepared by high temperature sintering and B-Ti-Al alloy fuels prepared by sonochemical synthesis are best choices whose gravimetric energy density measured by oxygen bomb calorimetry rival 33.3 kJ g−1 and 32.6 kJ g−1 respectively higher than the theoretical gravimetric energy density of Al that is 30.8 kJ g−1. The presence of Mg and Al can help to decrease the ignition delay time and increase the burning rate of boron fuels. MgB2 has the best ability for decreasing the ignition delay time by contrast. B-Fe alloy fuels prepared by high energy ball milling can increase the burning rate of solid propellant significantly. These boron-based alloy fuels are expected to be applicated actually in solid fuel-rich propellants through further studies.