Sonochemically generated reactive metal nanopowders containing Ti, Al, and B represent a new class of high-energy-density nanopowder fuels with superior energy content and air stability as compared to nano-aluminum. In this work, we optimize the energy density of a Ti-Al-B reactive metal nanopowder fuel by varying the Ti:Al:B ratios using a sonochemically mediated decomposition of a complex metal-hydride. After heating the recovered solids under vacuum to temperatures in the range between 150 to 300 degrees C, the powder's air stability is significantly improved so that it can be handled in air. Variable-temperature vacuum heat treatment was used to produce fuels tuned to be stable with a gravimetric energy density exceeding that of pure bulk Al (>31 kJ/g). The density of the powder was found to be 2.62 g/cm(3) by helium pycnometry, which translates to an impressive volumetric energy content of 89 kJ/cm(3). In poly(methyl methacrylate)-protected bomb calorimetry tests commercial nano-aluminum (SkySpring Nanomatetials, 20% oxide) only produced 25 kJ/g, while the sonochemically generated Ti-Al-B nanopowders released 24% more energy per unit mass and 19% more energy per unit volume in identical experiments.