Thermal conductivity degradation of ceramic materials due to low temperature, low dose neutron irradiation
Thermal conductivity degradation of ceramic materials due to low temperature, low dose neutron irradiation
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DOI：
10.1016/j.jnucmat.2004.11.009
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发表时间：
2005-04
影响因子：
3.1
通讯作者：
L. Snead;S. Zinkle;D. P. White
中科院分区：
文献类型：
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作者：
L. Snead;S. Zinkle;D. P. White
研究了低温中子辐照引起的热导率下降，并用热阻术语进行了量化。假设中子辐照对umklapp散射没有影响。提出了一个理论模型来量化的相对声子散射效率的三个主要缺陷类型产生的中子辐照：点缺陷，位错环和空隙。几种商业陶瓷已经在低温下用裂变反应堆快中子辐照产生缺陷。材料包括碳化硅、蓝宝石、多晶氧化铝、氮化铝、氮化硅、氧化铍和碳纤维复合材料。中子剂量对应于0.001和0.01位移每原子（dpa）为1060 °C照射和0.01和0.1dpa为10300 °C照射。在60°C下照射到仅0.001dpa的剂量后，除了BeO之外，所有材料都发生了显著的热导率降解。的数据进行了讨论的有效增加热阻所造成的不同的照射条件。在60和300°C的辐照过程中，获得了所有陶瓷的显著点缺陷迁移率的证据。辐射缺陷的热稳定性通过等时退火至1050°C来研究。
The thermal conductivity degradation due to low-temperature neutron irradiation is studied and quantified in terms of thermal resistance terms. Neutron irradiation is assumed to have no effect on umklapp scattering. A theoretical model is presented to quantify the relative phonon-scattering effectiveness of the three dominant defect types produced by neutron irradiation: point defects, dislocation loops and voids. Several commercial ceramics have been irradiated with fission reactor fast neutrons at low temperatures to produce defects. Materials include silicon carbide, sapphire, polycrystalline alumina, aluminum nitride, silicon nitride, beryllium oxide, and a carbon fiber composite. The neutron dose corresponded to 0.001 and 0.01 displacements per atom (dpa) for a ∼60°C irradiation and 0.01 and 0.1dpa for a ∼300°C irradiation. Substantial thermal conductivity degradation occurred in all of the materials except BeO following irradiation at 60°C to a dose of only 0.001dpa. The data are discussed in terms of the effective increase in thermal resistance caused by the different irradiation conditions. Evidence for significant point defect mobility during irradiation at 60 and 300°C was obtained for all of the ceramics. The thermal stability of the radiation defects was investigated by isochronal annealing up to 1050°C.