Enhanced energetic behavior of boron through Mg incorporation: Synthesis, characterization, and performance evaluation

To optimize the energy release of boron (B), we originally prepared B@Mg composites via the electrical explosion of wires method. SEM-EDS, XPS, ATR-IR, and XRD results confirmed that nano-scale magnesium (Mg) particles adhere to the surface of B. The pressure cell results showed that with increasing Mg content, the peak pressure and pressurization rate initially increased and then decreased, peaking at B@9 %Mg with values of 40.28 kPa and 2350 kPa/s, which are 1.11 times and 2.41 times those of raw B, respectively. Laser ignition and combustion spectrum tests revealed that B@9 %Mg exhibited intense and complete energy release. The maximum flame height of the B@Mg/ammonium perchlorate (AP) mixture increases with higher Mg content due to synergistic effects within the B@Mg/AP system. The introduction of Mg promoted the shell-breaking of B@Mg composites, thus accelerating the ignition process. The co-combustion of Mg and B boosted the heat release, promoting AP decomposition. Small molecules from AP decomposition reduce particle agglomeration, enhancing combustion efficiency. Further transient reactivity evaluations on energetics with ammonium oxalate (AO) demonstrated that B@9 %Mg exhibited superior performance, with the fastest flame propagation speed, highest peak pressure, and pressurization rate, which are 2.10 times, 1.59 times, and 1.75 times those of raw B, respectively. Additionally, the high-temperature steam test results showed that B@9 %Mg had the highest pressurization rate of 25.47 MPa/s, 2.2 times that of raw B. Finally, SEM-EDS analysis of the combustion residue revealed that Mg alters the structural distribution of the residues. Different from the combustion products of raw B, Mg is uniformly distributed in the residues of B@9 %Mg, reducing the inhibition of B₂O₃ on the combustion of B behavior and thus enhancing its energy release.