Cyclic Deformation of [001]-aluminium Single Crystals
Cyclic Deformation of [001]-aluminium Single Crystals
复制标题
[001]-铝单晶的循环变形
DOI：
10.1016/s0921-5093(96)10261-6
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发表时间：
1996
期刊：
影响因子：
6.4
通讯作者：
N. Ryum
中科院分区：
文献类型：
--
作者：
M. Videm;N. Ryum
在10−4-10−3范围内的恒定塑性应变幅下，对具有[001]取向的纯铝单晶进行了对称推拉循环变形。循环应力响应曲线的特点是快速硬化，软化和二次硬化，而在任何应变水平的应力不饱和。从未观察到传统裂纹扩展的疲劳失效，但试样失效是由复杂的塑性崩溃机制。传统的滑移线很少被观察到。相反，非常典型的变形模式与绳状外观在低应变振幅，和粗花呢样外观在较高的应变振幅的发展。在塌陷状态下，滑移线也形成在宏带中。用透射电镜研究了位错结构，发现位错由{100}位错壁和拉长的胞组成。此外，在位错壁上观察到球形亚胞。
Cyclic deformation in symmetric push-pull of pure aluminium single crystals with [001] orientation has been carried out at constant plastic strain amplitudes within the range 10−4–10−3. The cyclic stress response curves are characterised by rapid hardening, softening and secondary hardening without saturation of the stress at any strain level. Fatigue failure by traditional crack growth was never observed, but the specimens failed by a complicated plastic collapse mechanism. Traditional slip lines were seldom observed. Instead, very characteristic deformation patterns with a cord-like appearance at low strain amplitudes, and a tweed-like appearance at higher strain amplitudes developed. In the collapse state, slip lines clustered in macrobands were also formed. The dislocation structure was studied by TEM and found to consist of {100} dislocation walls and elongated cells. In addition, spherical subcells were observed on the dislocation walls.