论文标题
BCC铁中冲击纹理的实验模拟：对铁陨石的影响
Experimental Simulations of Shock Textures in BCC Iron: Implications for Iron Meteorites
论文作者
论文摘要
铁陨石中的Neumann带，是kamacite（Fe-Ni合金）中的变形双胞胎，已知是一种特征性的质地，表明对陨石的母体的古代碰撞。我们在BCC铁上进行了一系列的冲击回收实验，在各种初始温度，室温，670 K和1100 K时，弹丸速度为1.5 km/sec，并对震惊的铁进行了退火实验。我们还使用ISALE-2D代码进行了数值模拟，以研究非透明靶标中的峰值压力和温度分布。根据实验室和数值实验，探索了压力和温度对双胞胎（Neumann带）形成和消失的影响。双胞胎是在室温和670 K进行的实验的运行产物中形成的，而在1100 K撞击形成的运行产物中未观察到它。当前的实验与数值模拟相结合，表明双胞胎是由1.5-2 GPA到13 GPA大约1.5-2 GPA的各种冲击压力形成的。铁中的双胞胎几乎通过在1070 K处退火而消失。在此压力范围内，带有Neumann带的铁陨石在此压力范围内被震惊，温度至少至少高达670 K，并且在Neumann带形成后未加热至高于1070 K的温度。
Neumann band in iron meteorites, which is deformation twins in kamacite (Fe-Ni alloy), has been known to be a characteristic texture indicating ancient collisions on parent bodies of meteorites. We conducted a series of shock recovery experiments on bcc iron with the projectile velocity at 1.5 km/sec at various initial temperatures, room temperature, 670 K, and 1100 K, and conducted an annealing experiment on the shocked iron. We also conducted numerical simulations with the iSALE-2D code to investigate peak pressure and temperature distributions in the nontransparent targets. The effects of pressure and temperature on the formation and disappearance of the twins (Neumann band) were explored based on laboratory and numerical experiments. The twin was formed in the run products of the experiments conducted at room temperature and 670 K, whereas it was not observed in the run product formed by the impact at 1100 K. The present experiments combined with the numerical simulations revealed that the twin was formed by impacts with various shock pressures from 1.5-2 GPa to around 13 GPa. The twin in iron almost disappeared by annealing at 1070 K. The iron meteorites with Neumann bands were shocked at this pressure range and temperatures at least up to 670 K, and were not heated to the temperatures above 1070 K after the Neumann band formation.
