The mechanical properties and the deformation microstructures of the C15 Laves phase Cr2Nb at high temperatures
The mechanical properties and the deformation microstructures of the C15 Laves phase Cr2Nb at high temperatures
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DOI：
10.1016/j.actamat.2006.10.048
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发表时间：
2007-04
期刊：
影响因子：
9.4
通讯作者：
A. Kazantzis;M. Aindow;I. Jones;G. Triantafyllidis;J. Hosson
中科院分区：
文献类型：
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作者：
A. Kazantzis;M. Aindow;I. Jones;G. Triantafyllidis;J. Hosson
采用1250 ~ 1550°C、10 - 5 ~ 5×10 - 3s-1的压缩试验和透射电镜研究了C15 Cr2 Nb Laves相的高温力学性能和变形机制。屈服过程中的压缩曲线中的应力峰解释使用类似于应变时效结合低初始密度的移动的位错的机制。主要的变形机制是由伯格斯矢量为1/2 <$110 <$的扩展位错引起的滑移，而孪生在10−4s−1时更常见。Schmid因子分析表明，孪晶是更可能的晶粒取向，以便有两个共面孪晶系统具有高和可比的解决剪切应力。孪晶产生非常各向异性的微观结构。这可能是由于同步剪切：一个自钉扎机制，需要合作运动的带状位错。
Compression tests between 1250 and 1550°C and 10−5and 5×10−3s−1and transmission electron microscopy have been employed to investigate the high temperature mechanical properties and the deformation mechanisms of the C15 Cr2Nb Laves phase. The stress-peaks in the compression curves during yielding were explained using a mechanism similar to strain aging combined with a low initial density of mobile dislocations. The primary deformation mechanism is slip by extended dislocations with Burgers vector 1/2〈110〉, whereas twinning is more frequent at 10−4s−1. Schmid factor analysis indicated that twinning is more probable in grains oriented so as to have two co-planar twinning systems with high and comparable resolved shear stresses. Twinning produced very anisotropic microstructures. This may be due to synchroshear: a self-pinning mechanism which requires co-operative motion of zonal dislocations.