Comparative Analysis of Energy Release Characteristics in Blast-Driven 4-mm Al-PTFE Reactive Material Casings Versus Bare Charges

This study systematically investigates blast-driven energy release from 4-mm-thick Al/PTFE reactive material casings under open-field conditions. As the first multi-parameter quantitative analysis of combat-representative thick casings (≥ 4 mm) in field environments, it addresses limitations of prior laboratory-scale studies on thin specimens (≤ 3 mm) under confinement. Through comparative experiments with bare charges, energy release was quantified using high-speed imaging (28,000 fps), distributed overpressure sensors (six piezoelectric transducers), and fragmentation analysis. Key findings include: (1) Fireball enhancement, with a 20.5% longer duration (100 versus 83 ms) and a 27.8% larger maximum diameter (3.49 versus 2.73 m at 40 ms), suggesting delayed chemical energy release; (2) spatially graded blast amplification, with peak overpressure gains ranging from 24.8% (2.5 m) to 53.3% (6 m), with an 81.5% increase in positive phase duration in the far field; and (3) synergistic damage, as evidenced by concentrated pits (171 pits, 12.7 pits/dm²) on witness plates, consistent with kinetic–chemical coupling. Collectively, these results suggest that thick reactive material casings can influence energy release timing to enhance both blast and thermal effects. This provides a technological pathway for developing high-efficiency multimode warheads against hardened targets.