Radiation evolution characteristics of the ejecta cloud produced by aluminum projectiles hypervelocity impacting aluminum plates

摘要

Series of hypervelocity impact tests of aluminum projectiles impacting aluminum plates were conducted using two-stage light gas gun, and the sequence spectrum and radiation evolution data under different impact conditions were obtained. The diameters of projectile ranged from 3 mm to 5 mm, the impact velocities varied from 3.13 km/s to 6.58 km/s, and the ambient pressures varied from 0.58 Pa to 990 Pa. In the use of the transient spectroscopy system, the two-sequence special spectra of the ejecta cloud in the band of 250 nm-310 nm were obtained, the colorimetric diagnosis method based on the special lines was developed, and the temperature and the particle number density of the impact products were obtained. Results show that the temperature of the impact products decreases with time in some tests, but increases with time in the other tests. The intensity evolution of special lines of the impact products were obtained by radiometer. It is found that when the ambient pressure is low enough and the impact velocity is high enough, three peaks exist in the radiation evolution curve. The requirements of the occurrence of the three peaks and the dependence of the three peaks on impact parameters were summarized.