Dynamic densification behavior of nanoiron powders under shock compression
Dynamic densification behavior of nanoiron powders under shock compression
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冲击压缩下纳米铁粉末的动态致密化行为
DOI：
10.1063/1.2908209
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发表时间：
2008
影响因子：
3.2
通讯作者：
N. Thadhani
中科院分区：
文献类型：
--
作者：
C. Dai;D. Eakins;N. Thadhani
利用压电式应力计测量了冲击输入应力和波速，确定了纳米铁粉(∼粒径25 nm)在∼35%和∼45%固体密度下的动态致密化行为。实验确定的冲击致密化响应对预压纳米铁粉压坯的初始密度(或孔隙率)很敏感。Hugoniot测量表明，在∼2 GPa下，∼密度为35%的粉末压坯有明显的致密化-膨胀转变，而∼为45%致密粉末压坯的∼为6 Gpa。用等压模型和等容线模型计算了纳米铁粉的致密化和冲击压缩响应。模型计算与测量数据的关联表明，现有的分析模型不能正确地描述纳米铁粉的冲击Hugoniot，否则，这些分析模型能够预测微米级粉末的高孔材料(预压坯)的Hugoniot。
The dynamic densification behavior of nanoiron powder (∼25nm particle size) prepressed to ∼35% and ∼45% of solid density was determined based on measurements of shock input stress and wave velocity by using piezoelectric stress gauges. The experimentally determined shock densification response is observed to be sensitive to the initial density (or porosity) of prepressed nanoiron powder compacts. Hugoniot measurements show an obvious densification-distension transition at ∼2GPa for the ∼35% dense and ∼6GPa for the ∼45% dense powder compacts. The densification and shock compression responses of the nanoiron powders are also calculated by using isobaric and isochoric models. Correlations of the model calculations with the measured data indicate that the shock Hugoniot of nanoiron powders cannot be correctly described by the currently available analytical models that are otherwise capable of predicting the Hugoniot of highly porous materials (prepressed compacts) of micron-sized powders.