Effect of Boron Nitride Content on the Explosion Performance of On-Site Mixed Emulsion Explosives

To investigate the effect of boron nitride (BN) content on the explosion performance of on-site mixed emulsion explosives, the microstructure of BN-containing on-site mixed emulsion explosives were characterized by transmission electron microscopy and optical microscopy, and the thermal sensitivity, shock wave parameters, detonation velocity, and brisance of explosives were measured through steel plate tests, air explosion tests, the probe method, and lead cylinder compression tests. Combined with theoretical calculations, the influence of BN content on the microstructure, thermal sensitivity, and explosion performance of explosives was systematically studied. The test results indicate that the addition of BN does not significantly affect the stability of the internal phase droplets. At 240 ℃, the explosion delay time of the explosive samples increased from 114.28 s (blank sample) to 173.95 s (1.2% h-BN). As the mass fraction of BN increased from 0 to 1.6%, the detonation velocity, brisance, peak overpressure and specific impulse exhibited a trend of increase followed by decrease. The detonation velocity increased from 3850.45 m/s to 4724.89 m/s, and then decreased to 3903.20 m/s, with a maximum increase of 22.71%; the brisance first increased from 13.86 mm to 19.87 mm, and then decreased to 17.18 mm, with a maximum increase of 43.36%; the peak overpressure increased from 136.44 kPa to 318.33 kPa, and then decreased to 285.41 kPa, with a maximum increase of 133.31%; the specific impulse increased from 9.23 Pa·s to 33.98 Pa·s, and then decreased to 31.99 Pa·s, with a maximum increase of 268.15%. The study demonstrates that the incorporation of an appropriate amount of BN can significantly enhance the explosion performance of site-mixed emulsion explosives.