Crystallographic characterization of catastrophic shear in submicron nickel at low temperatures
Crystallographic characterization of catastrophic shear in submicron nickel at low temperatures
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低温下亚微米镍灾难性剪切的晶体学表征
DOI：
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发表时间：
2010
期刊：
影响因子：
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通讯作者：
W. Skrotzki
中科院分区：
文献类型：
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作者：
S. Dey;L. Hollang;K. Reuther;R. Hübner;R. Chulist;W. Skrotzki
通过无添加剂脉冲电沉积生产的镍，晶粒尺寸约为 150 nm，在 320 K 和 4 K 下拉伸变形。在这两个温度下，样品都表现出强烈的抛物线硬化和良好的延展性。然而，在 4 K 时，发生了从均匀变形到重复灾难性剪切的突然转变。剪切区域的微观结构特征显示变形晶粒在拉伸轴和生长方向之间拉长。使用透射电子显微镜中的锥形暗场测量获得剪切区域的纹理信息。变形 4 K 样本的极图显示了典型的剪切纹理，与起始纹理明显不同。
Nickel produced by additive-free pulsed electro-deposition with grain size of about 150 nm was deformed in tension at 320 K and 4 K. At both temperatures the specimens exhibited strong parabolic hardening and good ductility. However, at 4 K a sudden transition from homogeneous deformation to repeated catastrophic shear took place. Microstructural characterization of the sheared region showed deformed grains elongated in between tensile axis and growth direction. The texture information from the sheared region was obtained using conical dark field measurements in the transmission electron microscope. The pole figures of the deformed 4 K specimen show a typical shear texture which clearly differs from the starting texture.