Evolution of dislocation structure induced by cyclic deformation in a directionally solidified cobalt base superalloy
Evolution of dislocation structure induced by cyclic deformation in a directionally solidified cobalt base superalloy
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DOI：
10.1179/026708399101505707
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发表时间：
1999-02
影响因子：
1.8
通讯作者：
Zhenhuan Lu;Yantao Xu;Zushu Hu
中科院分区：
文献类型：
--
作者：
Zhenhuan Lu;Yantao Xu;Zushu Hu
在不同总应变幅的控制下，室温下定向凝固钴基高温合金在空气中进行了循环变形。利用TEM研究了循环应力响应曲线中不同阶段的位错结构。观察表明，在初始硬化阶段形成大量的堆垛层错和断层交叉，从而导致合金的初始硬化。然而，六方密堆积（hcp）区和孪晶的形成被认为是循环饱和的原因。提出了从堆垛层错到 hcp 层结构和孪晶的转变模型。
Cyclic deformation has been carried out on a directionally solidified cobalt base superalloy at room temperature in air under the control of different total strain amplitudes. Dislocation structures of different stages in the cyclic stress response curve were studied by TEM. Observations show that a large number of stacking faults and fault intersections are formed in the initial hardening stage, and this leads to the initial hardening of the alloy. However, formation of hexagonally close packed (hcp) zones and twins is proposed to be the cause of cyclic saturation. Models for both the transition from stacking faults to a hcp layer structure and to twins are proposed.