Compressive mechanical behavior of nanocrystalline Fe investigated with an automated ball indentation technique
Compressive mechanical behavior of nanocrystalline Fe investigated with an automated ball indentation technique
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DOI：
10.1016/s0921-5093(98)00661-3
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发表时间：
1998-08
期刊：
影响因子：
6.4
通讯作者：
T. Malow;C. Koch;P. Miraglia;K. Murty
中科院分区：
文献类型：
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作者：
T. Malow;C. Koch;P. Miraglia;K. Murty
纳米晶（NC）铁是通过机械研磨和压制成接近完全致密的样品。在800 K等温退火导致晶粒尺寸在15和24 nm之间。一个新的可用的自动球压痕系统被用来研究样品的压缩力学性能。ABI方法被证明是有用的，在更定量的水平上比以前可能通过传统的硬度测试方法检查数控铁的机械性能。得到的应力-应变曲线表明压缩行为类似于理想塑性材料：低应变硬化在高流动应力约3 GPa和低的室温应变率敏感性。在本研究的范围内，流动应力与晶粒尺寸无关。压痕周围的变形堆积似乎是不均匀形成的，在局部剪切带中表现出强烈的塑性变形。
Nanocrystalline (nc) iron was produced by mechanical attrition and compacted into near fully dense samples. Isothermal annealing at 800 K resulted in grain sizes between 15 and 24 nm. A newly available Automated Ball Indentation system was used to study the compressive mechanical properties of the samples. The ABI method proved useful in examining the mechanical properties of nc iron on a more quantitative level than previously possible by conventional hardness testing methods. Stress–strain curves were obtained which indicated a compressive behavior similar to that of perfectly plastic materials: low strain hardening at high flow stresses around 3 GPa and a low room-temperature strain-rate sensitivity. The flow stresses were independent of the grain size in the range of the present study. The deformation pile-up around the indentations seems to have formed inhomogeneously, exhibiting intense plastic deformation in localized shear bands.