Abstract High-energy atomic impacts represent one of the biggest threats to material performance in both the low earth orbit (LEO) and deep space environment. However, while significant test data exists for LEO atomic oxygen (AO) collisions, further research is needed on the effect of high-energy collisions that can potentially occur in deeper space. As such, this study investigated using the ReaxFF force field in molecular dynamics to simulate the impact of atomic oxygen on two common spacecraft metals, silver and aluminum. This study used a Wigner-Seitz defect analysis to track the damage evolution of the remaining substrate during impact. Results indicated that for both silver and aluminum the number of defects and depth of damage increased linearly with impact energy. While silver was shown to have a higher erosion yield than aluminum, its substrate formed less defects at all impact energies considered. The source of this discrepancy was attributed to the lower energy needed to form vacancies in aluminum as compared to silver. Our results show that while erosion is certainly an important parameter in measuring the damage to a material by high-energy impacts, it is not sufficient to describe the amount of damage and state of the remaining substrate. Overall, this study demonstrates the potential for molecular dynamics simulations to be used to compare material performance and degradation in harsh deep space environments where testing may not be possible.

中文翻译：

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原子氧通量和冲击能量对航天器金属损伤的影响

摘要 在低地球轨道 (LEO) 和深空环境中，高能原子撞击是对材料性能的最大威胁之一。然而，虽然低地球轨道原子氧 (AO) 碰撞存在重要的测试数据，但需要进一步研究可能发生在更深空间的高能碰撞的影响。因此，本研究调查了在分子动力学中使用 ReaxFF 力场来模拟原子氧对两种常见航天器金属银和铝的影响。本研究使用 Wigner-Seitz 缺陷分析来跟踪撞击过程中剩余基材的损伤演变。结果表明，对于银和铝，缺陷数量和损伤深度随冲击能量线性增加。虽然银被证明具有比铝更高的侵蚀率，在所有考虑的冲击能量下，其基材形成的缺陷较少。这种差异的根源在于与银相比，在铝中形成空位所需的能量较低。我们的结果表明，虽然侵蚀肯定是衡量高能冲击对材料损坏的重要参数，但不足以描述剩余基材的损坏程度和状态。总体而言，这项研究证明了分子动力学模拟可用于在可能无法进行测试的恶劣深空环境中比较材料性能和退化的潜力。我们的结果表明，虽然侵蚀肯定是衡量高能冲击对材料损坏的重要参数，但不足以描述剩余基材的损坏程度和状态。总体而言，这项研究证明了分子动力学模拟可用于在可能无法进行测试的恶劣深空环境中比较材料性能和退化的潜力。我们的结果表明，虽然侵蚀肯定是衡量高能冲击对材料损坏的重要参数，但不足以描述剩余基材的损坏程度和状态。总体而言，这项研究证明了分子动力学模拟可用于在可能无法进行测试的恶劣深空环境中比较材料性能和退化的潜力。