纳米压痕技术对比研究DNAN和TNT晶体的微观力学性能

通过溶剂挥发法制备了DNAN和TNT晶体;利用纳米压痕技术研究了DNAN和TNT晶体的微观力学性能(硬度和弹性模量);通过原位扫描探针成像技术(SPM)研究了DNAN和TNT晶体的压痕形貌随时间的变化差异。结果表明,DNAN晶体的平均硬度和弹性模量分别为7.82GPa和0.22GPa,TNT晶体的平均硬度和弹性模量分别为12.19GPa和0.48GPa,表明TNT抵抗变形的能力优于DNAN;随着压痕深度由118nm增至856nm,DNAN的硬度从0.61GPa降至0.22GPa;随着压痕深度由27nm增至481nm,TNT的硬度从2.9GPa降至0.48GPa,表明DNAN和TNT均存在尺寸效应。随着时间由0增至50.4min,DNAN的压痕深度由-270.99nm减至-44.28nm,TNT的压痕深度由-415.12nm减至-369.21nm,表明DNAN晶体比TNT晶体具有更明显的慢回弹性,DNAN具有更强的冲击能量吸收能力。

Comparative Study on Micromechanical Properties of DNAN and TNT Crystals by Nanoindentation

The DNAN and TNT crystals were prepared by solvent evaporation method.The micromechanical properties (hardness and elastic modulus)of DNAN and TNT crystals were studied by nanoindentation.The difference of variation of indentation with time was investigated by in situ scanning probe microscopy(SPM).The results show that the average hardness and elastic modulus are 7.82GPa and 0.22GPa for DNAN and 12.19GPa and 0.48GPa for TNT, respectively, indicating that the ability of resistance to deformation of TNT is stronger than that of DNAN.With increasing the indentation depth from 118nm to 856nm, the hardness of DNAN reduces from 0.61GPa to 0.22GPa;With increasing the indentation depth from 27nm to 481nm, the hardness of TNT reduces from 2.9GPa to 0.48GPa, revealing that DNAN and TNT have size-effect.With increasing the time from 0 to 50min, the indentation depth reduces from-270.99nm to-44.28nm for DNAN and from-415.12nm to-369.21nm for TNT, showing that the elastic resilience of DNAN crystal has more obvious slow elastic resilience than that of TNT crystal, which means DNAN has stronger ability to absorb impact energy.