Revealing cryogenic mechanical behavior and mechanisms in a microstructurally-stable, immiscible nanocrystalline alloy
Revealing cryogenic mechanical behavior and mechanisms in a microstructurally-stable, immiscible nanocrystalline alloy
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DOI：
10.1016/j.scriptamat.2018.09.035
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发表时间：
2019-02
影响因子：
6
通讯作者：
B. Hornbuckle;C. Kale;S. Srinivasan;T. Luckenbaugh;K. Solanki;K. Darling
中科院分区：
文献类型：
--
作者：
B. Hornbuckle;C. Kale;S. Srinivasan;T. Luckenbaugh;K. Solanki;K. Darling
本文从变形机制变化的角度研究了微结构稳定的Cu-3Ta （at.%）纳米晶合金的Cottrell-Stokes比。为此，在113 K - 273 K温度范围内进行了单轴压缩实验。在低温条件下，该材料的Cottrell-Stokes比为~1.3，在低温条件下表现出极低的应变速率敏感性。透射电镜（TEM）表征表明，随着测试温度的降低，平均晶粒尺寸的粗化可以忽略不计，变形机制向孪晶等非热活化过程转变。
Here, the Cottrell–Stokes ratio in a microstructurally-stable Cu-3Ta (at.%) nanocrystalline alloy is examined from the standpoint of changes in deformation mechanisms. Toward this, uniaxial compression experiments were performed in the temperature range of 113 K – 273 K. The Cottrell-Stokes ratio at the lowest temperature tested was ~1.3, and the material exhibited a very low strain-rate sensitivity at cryogenic-temperatures. Transmission electron microscopy (TEM) characterization showed negligible average grain size coarsening and a transition in the deformation mechanism toward athermal activation processes such as twinning with the reduction in the testing temperature.