Advancing boron-based thermites via TiB2 as a fuel

Thermite is widely utilized in fields such as munitions, propulsion, welding, and materials synthesis. In particular, boron (B)-based thermites have shown promising thermochemical properties due to the high energy densities of B. However, challenges such as high ignition temperature and low combustion efficiency of B particles have hindered their broader application. To enhance the heat release performance of B-based thermites, this study introduces a novel boride fuel, titanium diboride (TiB 2 ), and experimentally compares the thermal oxidation and combustion characteristics of TiB 2 /CuO thermite and conventional B/CuO thermite under both slow heating and laser-induced fast heating conditions. Results demonstrate that TiB 2 /CuO thermite showed better ignition and combustion performance than B/CuO thermite. Under the optimal fuel-rich condition (Φ = 2), the ignition delay time of TiB 2 /CuO thermite is reduced by 57.7% compared with B/CuO thermite. Moreover, due to the high reactivity of TiB 2 and the catalytic action of TiO x , the flame temperature and radiation intensity of TiB 2 /CuO thermite are significantly higher than that of B/CuO thermite during intense combustion. The onset reaction temperature decreased from 537 °C for B/CuO thermite to 422 °C for TiB 2 /CuO thermite. Characterization of the combustion products indicates that TiB 2 /CuO thermite reaction produces distinctive hollow TiO 2 shells and ‘pocket-like’ structures. Finally, mechanistic analysis proposes two pathways for TiB 2 /CuO: complete combustion forming hollow shells driven by B oxide vaporization, and incomplete combustion yielding porous agglomerates due to TiO 2 encapsulation. These findings highlight TiB 2 /CuO’s superior combustion performance over B/CuO, offering fundamental insights and experimental support for optimizing high-energy thermite formulations.