Statistical heterogeneity of plastic deformation: An investigation based on surface profilometry
Statistical heterogeneity of plastic deformation: An investigation based on surface profilometry
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DOI：
10.1016/j.actamat.2010.05.024
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发表时间：
2010-08
期刊：
影响因子：
9.4
通讯作者：
J. Schwerdtfeger;E. Nadgorny;V. Koutsos;J. Blackford;M. Zaiser
中科院分区：
文献类型：
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作者：
J. Schwerdtfeger;E. Nadgorny;V. Koutsos;J. Blackford;M. Zaiser
本文通过分析原子力显微镜和扫描白色光干涉仪记录的晶体材料表面轮廓，研究了晶体材料塑性变形的内在空间不均匀性。记录了三种类型的碱金属卤化物单晶压缩变形前后的分布：生长（AG）KCl和LiF和辐照（IR）LiF。的配置文件，其特征在于在他们的高度高度相关函数和尺度依赖的粗糙度。我们还研究了表面台阶高度的统计，发现AG晶体中台阶高度的无标度分布超过三个数量级（nm至μm）。在低塑性应变下，在IR LiF中观察到不同的图片，在那里我们可以确定明确的特征台阶高度。我们讨论这些发现的滑移雪崩所造成的集体运动的位错。
The present paper investigates the intrinsic spatial heterogeneity of plastic deformation of crystalline materials by analysing surface profiles recorded by atomic force microscopy and scanning white light interferometry. Profiles were recorded before and after compressive deformation of three types of alkali halide single crystals: as-grown (AG) KCl and LiF and irradiated (IR) LiF. The profiles were characterized in terms of their height–height correlation function and scale-dependent roughness. We also investigated the statistics of surface step heights and found scale-free distributions over about three orders of magnitude in step (nm to μm) in the AG crystals. A different picture was observed in IR LiF at low plastic strains, where we could identify well-defined characteristic step heights. We discuss these findings in terms of slip avalanches caused by collective motion of dislocations.