Initiation and propagation of cleared channels in neutron-irradiated pure copper and a precipitation hardened CuCrZr alloy
Initiation and propagation of cleared channels in neutron-irradiated pure copper and a precipitation hardened CuCrZr alloy
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DOI：
10.1016/j.jnucmat.2005.04.001
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发表时间：
2005-06
影响因子：
3.1
通讯作者：
D. Edwards;B. N. Singh;J. Bilde-Sørensen
中科院分区：
文献类型：
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作者：
D. Edwards;B. N. Singh;J. Bilde-Sørensen
40多年来，人们经常报道在中子辐照的金属和合金中形成“清除”的通道。然而，到目前为止，还没有明确和确凿的证据表明这些渠道是如何以及在哪里启动的。在接下来的实验中，我们给出了中子辐照铜和铜合金辐照后形变过程中沟道的萌生和扩展的实验结果。这些观测结果强烈地表明，这些通道是在边界、大型包裹体甚至以前形成的清除通道处开始的。观察到一些通道既能穿透孪晶界又能穿透晶界。认为在辐照后拉伸试验中达到的高应力水平激活了晶界和界面应力集中部位的位错源。这些新产生的位错在基质中的传播导致清除沟道的形成。讨论了这些结果的含义，特别是关于塑性流动局部化的起源和后果。
The formation of ‘cleared’ channels in neutron irradiated metals and alloys have been frequently reported for more than 40 years. So far, however, no unambiguous and conclusive evidence showing as to how and where these channels are initiated has emerged. In the following we present experimental results illustrating initiation and propagation of channels during post-irradiation deformation of neutron irradiated copper and a copper alloy. The observations strongly suggest that the channels are initiated at boundaries, large inclusions and even at previously formed cleared channels. Some of the channels have been observed to penetrate through both the twin boundaries and grain boundaries. It is argued that the high stress level reached during post-irradiation tensile tests activate dislocation sources at the sites of stress concentrations at boundaries and interfaces. The propagation of these newly generated dislocations in the matrix causes the formation of cleared channels. Implications of these results are discussed with specific reference to the origin and consequences of plastic flow localization.