Influence of single and multiple slip conditions and temperature on the size effect in micro bending
Influence of single and multiple slip conditions and temperature on the size effect in micro bending
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DOI：
10.1016/j.actamat.2018.05.054
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发表时间：
2018-08
期刊：
影响因子：
9.4
通讯作者：
Jorge Rafael Velayarce;M. Zamanzade;O. T. Abad;C. Motz
中科院分区：
文献类型：
--
作者：
Jorge Rafael Velayarce;M. Zamanzade;O. T. Abad;C. Motz
利用厚度为1 ~ 5 μm的单晶微弯梁，研究了晶体取向和温度对尺寸效应的影响。研究了两种晶体取向：单滑移的{111}<153>和多滑移的{111}<001>。弯曲测试用安装在扫描电子显微镜中的纳米压头在室温和200 °C之间的温度下进行。结果清楚地表明，除了越小越强的现象外，尺寸效应还受温度的影响，特别是在单滑移取向的梁中。我们证明，在应变梯度的存在下，机械响应是由位错堆积低于临界梁的大小，在单滑移条件下更明显。堆积，但是，崩溃的“温度诱导”的交叉滑移随着温度的升高，而在较大的样品，位错网络支配的强度。
The present work investigates the effect of crystal orientation and temperature on the size effect using micro-sized single-crystal bending beams of copper with thicknesses between 1 and 5 μm. Two crystal orientations were studied: {111}<153> for single slip and {111}<001> for multiple slip. The bending tests were carried out with a nanoindenter installed in a scanning electron microscope at temperatures between room temperature and 200 °C. The results show clearly that, besides the phenomenonsmaller is stronger, the size effect is influenced by temperature particularly in beams oriented for single slip. We demonstrated that, in the presence of strain gradients, the mechanical response is governed by dislocation pile-ups below a critical beam size, being more pronounced in single slip conditions. The pile-ups, however, collapse by “temperature-induced” cross-slip with increasing temperature, while in bigger samples, dislocation networks govern the strength.