High temperature annealing of ion irradiated tungsten
High temperature annealing of ion irradiated tungsten
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DOI：
10.1016/j.actamat.2015.01.067
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发表时间：
2015-05-15
期刊：
影响因子：
9.4
通讯作者：
Roberts, Steve G.
中科院分区：
文献类型：
--
作者：
Ferroni, Francesco;Yi, Xiaoou;Roberts, Steve G.
用透射电子显微镜观察了自离子辐照纯钨的高温退火过程，以阐明在与聚变反应堆应用相关的温度范围内（500-1200 ℃）的微观结构和缺陷演变。在800、950、1100和1400 ℃温度下，对离子辐照纯钨（2 MeV W+离子，500 ℃，10（14）W+/cm（2））进行体等时和等温退火，退火时间为0.5 ~ 8 h，然后对缺陷尺寸、数量密度、Burgers矢量和性质进行非原位表征。考虑直径大于2-3 nm的环进行详细分析，其中所有环的B = 1/2< 111 >，并且主要为间质性质。还进行了从300到1200摄氏度的原位退火实验，包括动态温度上升。这些证实了900 ℃以上的环路损耗加速。在此范围内的不同温度下，位错表现出的行为，如初始孤立的环跳跃，然后大规模的重排成环链，合并，最后线环相互作用和广泛的吸收自由表面在温度升高。导出了位错长度退火的激活能，发现在700-1100 ℃范围内E-a = 1.34 +/- 0.2 eV。(C)2015 Acta Materialia Inc.由爱思唯尔有限公司出版。保留所有权利。
Transmission electron microscopy of high temperature annealing of pure tungsten irradiated by self-ions was conducted to elucidate microstructural and defect evolution in temperature ranges relevant to fusion reactor applications (500-1200 degrees C). Bulk isochronal and isothermal annealing of ion irradiated pure tungsten (2 MeV W+ ions, 500 degrees C, 10(14) W+/cm(2)) with temperatures of 800, 950,1100 and 1400 degrees C, from 0.5 to 8 h, was followed by ex situ characterisation of defect size, number density, Burgers vector and nature. Loops with diameters larger than 2-3 nm were considered for detailed analysis, among which all loops had b = 1/2 < 111 > and were predominantly of interstitial nature. In situ annealing experiments from 300 up to 1200 degrees C were also carried out, including dynamic temperature ramp-ups. These confirmed an acceleration of loop loss above 900 degrees C. At different temperatures within this range, dislocations exhibited behaviour such as initial isolated loop hopping followed by large-scale rearrangements into loop chains, coalescence and finally line loop interactions and widespread absorption by free-surfaces at increasing temperatures. An activation energy for the annealing of dislocation length was derived, finding E-a = 1.34 +/- 0.2 eV for the 700-1100 degrees C range. (C) 2015 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.