Erosion of POSS-polyimide films under hypervelocity impact and atomic oxygen: The role of mechanical properties at elevated temperatures
Erosion of POSS-polyimide films under hypervelocity impact and atomic oxygen: The role of mechanical properties at elevated temperatures
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DOI：
10.1016/j.actamat.2008.10.054
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发表时间：
2009-02-01
期刊：
影响因子：
9.4
通讯作者：
Eliaz, N.
中科院分区：
文献类型：
--
作者：
Verker, R.;Grossman, E.;Eliaz, N.
近地轨道碎片对石油的影响卫星外表面近年来急剧增加。聚酰亚胺被用作热控隔热毯的外层。覆盖了暴露在空间环境中的大部分航天器外部表面。一种新开发的材料，称为多面体低聚倍半硅氧烷(POSS)-聚酰亚胺。在抵御空间环境方面表现出显著的增强。在这项工作中。研究了地面模拟超高速空间碎片撞击和原子氧(AO)对含POSS聚酰亚胺薄膜冲蚀的联合作用。在这样的超高速撞击过程中，形成了数百度的高温。激光驱动的飞片系统被用来加速铝飞片以高达3公里的速度撞击S(-1)。受影响的薄膜暴露在氧气射频等离子体环境中，模拟低地球轨道上的声光效应。受冲击的聚酰亚胺薄膜在AO作用下表现出协同冲蚀效应，而含POSS的冲击聚酰亚胺薄膜具有更好的抗冲蚀性能。冲击聚酰亚胺薄膜的冲蚀速率增加是由于残余应力的形成，这些残余应力主要通过增加氧向次表层的扩散系数来影响氧化。在450℃下进行的含POSS样品的机械性能和断口检查支持上述假设。(C)2008 Acta Materialia Inc.由爱思唯尔有限公司出版。版权所有。
Low Earth orbital debris impacts oil the external Surfaces of satellites have increased dramatically in recent years. Polyimides are used as the outer layer of thermal control insulation blankets. covering most of the external spacecraft surfaces that are exposed to the space environment. A recently developed material, named polyhedral oligomeric silsesquioxane (POSS)-polyimide. shows significant enhancement in withstanding the space environment. In this work. the combined effect of ground-simulated hypervelocity space debris impacts and atomic oxygen (AO) on the erosion of POSS-containing polyimide films was investigated. During Such hypervelocity impacts, elevated temperatures, on the order of hundreds degrees, arc Formed. A laser-driven flyer system was used to accelerate aluminum flyers to impact velocities of up to 3 km s(-1). The impacted films were exposed to an oxygen RF plasma environment, simulating the effect of AO in the low Earth orbit. Impacted polyimide films exposed to AO revealed synergistic erosion effect, while impacted POSS-containing samples showed improved erosion resistance. The increased erosion rate of the impacted polyimide film is explained by formation of residual stresses that affect the oxidation mainly by increasing the diffusivity of oxygen into the subsurface layers. Mechanical properties of the POSS-containing samples performed at 450 degrees C and fractographic examination supports the above hypothesis. (C) 2008 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.