Dynamic Mechanical Behavior and Hypervelocity Impact Performance of an Al-Based Nanocrystalline Alloy

摘要

In a wide strain rate range from 10^(-5)to 10~3s^(-1),the deformation behavior of an Al-based nanocrystalline alloy was investigated.After fracture,the debris collected was used for statistical analysis,which is expected to reflect the profile of the fracture behavior of the alloy.The energy absorption of alloy at different strain rates was elucidated on account of mass distribution of debris.Based on the parameters obtained by the compression experiment at different strain rates,the numerical simulation experiment was carried out to evaluate the performance of Al-based nanocrystalline alloy as spacecraft shielding.The results suggest that Al-based nanocrystalline alloys have better shield performance than aluminum alloy under the identical areal density at velocity of 1–7 km/s.The better shield performance is attributed to high fracture strength,high hardness and low toughness of Al-based nanocrystalline alloy as compared with those of aluminum alloy.