铝弹丸超高速正撞击铝合金薄板产生溅射物云特性研究

Characteristics of ejecta cloud generated due to aluminum projectiles' impacting aluminum thin plate at hypervelocity

为研究微流星体或空间碎片超高速正撞击航天器表面缓冲结构产生的溅射物形态和分布特性,采用二级轻气炮驱动铝弹丸进行超高速撞击实验。铝弹丸超高速正撞击铝合金薄板首先溅射高温微粒子或甚至是微小熔滴等闪光热源,随后是由金属粉尘及低速碎片粒子构成的溅射物云团簇。正撞击产生的溅射云团簇在空间呈环锥形状分布,3~5 km/s速度范围内,撞击速度越高,分布越密集。利用HSFC-PRO超高速相机捕捉到撞击初始阶段产生的溅射物在不同时刻的影像演化,通过跟踪影像中溅射闪光热源和溅射云团簇最前端的轮廓估算其一维膨胀速度。非球弹丸撞击时的姿态偏转可能对溅射物云团簇的分布有较大影响。

Morphology and distribution characteristics of ejecta cloud generated due to micrometeoroids or space debris impacting a spacecraft surface buffer structure were studied.A two-stage light gas gun was used to accelerate aluminum projectiles to perform hypervelocity impact tests.It was shown that aluminum projectiles’impact an aluminum thin plate at hypervelocity to sputter high temperature particles or even tiny molten droplets,etc.flash heat sources,then ejecta cloud clusters composed of metal dust and micro-debris with low velocity;those ejecta cloud clusters produced by normal impact reveal a ring cone shape distribution,the higher the impact speed,the denser the distribution,within the impact speed range of3-5km/s.Ultra-high speed camera HSFC-PRO was employed to capture the image evolution of ejecta cloud at different instants during initial impact stage.Ejecta cloud’s one dimensional expansion velocity was estimated through tracking front outlines of flash heat sources and ejecta cloud clusters.Attitude excursion of non-sphere projectiles during impacting might have more effects on distribution of ejecta cloud clusters.