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为了提高航天器对空间碎片的防护能力,设计了以TiB_2基陶瓷复合材料为缓冲屏的Whipple式防护构型(单层TiB_2基陶瓷缓冲屏以及TiB_2基陶瓷/铝合金缓冲屏),利用二级轻气炮在2.88~7.32 km/s的撞击速度范围内开展超高速撞击实验,并对上述缓冲屏与典型全铝合金缓冲屏进行比较验证。通过分析不同撞击速度下缓冲屏的穿孔、后墙损伤、碎片云结构特征,并结合SEM微观损伤形貌和EDS元素分布模式,重点阐述了不同缓冲屏材料特性与结构特性对碎片云形成以及后墙撞击成坑之间的作用关系。研究表明,单层TiB_2基陶瓷复合材料缓冲屏可以有效破碎铝合金弹丸获得更加细小的碎片云颗粒,由于碎片云动能被有效分散到更为广泛的细小碎片颗粒当中,从而获得比等面密度典型全铝缓冲屏更为优异的防护性能,且防护性能随着撞击速度的增加而有所提高。相反的,TiB_2基陶瓷/铝合金缓冲屏由于异质材料之间波阻抗的明显差异,在超高速撞击下会导致陶瓷前面板的严重断裂并造成铝合金后板的花瓣状破坏,且损伤程度随着撞击速度和弹丸尺寸的增加而增加,由于不能有效细化碎片云颗粒,其防护效能反而低于等面密度典型全铝缓冲屏。
In order to improve the spacecraft’s ability to protect the spacecraft, a Whipple-type protective structure (single-layer TiB_2-based ceramic buffer screen and TiB_2-based ceramic / aluminum alloy buffer screen) with TiB_2 based ceramic composite as the buffer screen was designed. Light gas gun in the 2.88 ~ 7.32 km / s impact velocity range of ultra-high-speed impact test carried out, and the buffer and typical all-aluminum buffer screen for comparison and validation. By analyzing the characteristics of the perforation, rear wall damage and debris cloud structure under different impact velocities, combined with the SEM micro-damage morphology and EDS elemental distribution patterns, the characteristics and structural characteristics of different buffer screen materials are mainly discussed. Wall collision into the role of the pit. The research shows that the single TiB 2 ceramic composite buffer screen can effectively crush the aluminum alloy projectile to obtain more fine debris cloud particles. Because the cloud kinetic energy of the debris cloud is effectively dispersed into a wider range of fine debris particles, the specific isosurface density All-aluminum buffer screen more excellent protection performance, and protective properties as the impact rate increases. On the contrary, due to the significant difference in wave impedance between TiB_2-based ceramic / aluminum alloy buffer plates, the ultra-high-speed impact will cause severe fracture of the ceramic front panel and cause the petaloid damage of the aluminum alloy rear plate, and the degree of damage With the increase of the impact velocity and the size of the projectile, the protective effect is lower than that of the typical all-aluminum buffer screen of isosurface because the particle cloud can not be effectively refined.