Parks David A, Tittmann Bernhard R
IEEE Trans Ultrason Ferroelectr Freq Control. 2014 Jul;61(7):1216-22. doi: 10.1109/TUFFC.2014.3020.
For practical use in harsh radiation environments, we pose selection criteria for piezoelectric materials for non-destructive evaluation (NDE) and material characterization. Using these criteria, piezoelectric aluminum nitride is shown to be an excellent candidate. The results of tests on an aluminum-nitride- based transducer operating in a nuclear reactor are also presented. We demonstrate the tolerance of single-crystal piezoelectric aluminum nitride after fast and thermal neutron fluences of 1.85 x 10(18) neutron/cm(2) and 5.8 x 10(18) neutron/ cm(2), respectively, and a gamma dose of 26.8 MGy. The radiation hardness of AlN is most evident from the unaltered piezoelectric coefficient d33, which measured 5.5 pC/N after a fast and thermal neutron exposure in a nuclear reactor core for over 120 MWh, in agreement with the published literature value. The results offer potential for improving reactor safety and furthering the understanding of radiation effects on materials by enabling structural health monitoring and NDE in spite of the high levels of radiation and high temperatures, which are known to destroy typical commercial ultrasonic transducers.
为了在恶劣辐射环境中实际应用，我们提出了用于无损检测（NDE）和材料表征的压电材料选择标准。根据这些标准，压电氮化铝被证明是一个极佳的候选材料。本文还展示了在核反应堆中运行的基于氮化铝的换能器的测试结果。我们分别展示了单晶压电氮化铝在快中子注量为1.85×10¹⁸中子/cm²、热中子注量为5.8×10¹⁸中子/cm²以及伽马剂量为26.8 MGy后的耐受性。氮化铝的辐射硬度最明显地体现在未改变的压电系数d33上，在核反应堆堆芯经过超过120兆瓦时的快中子和热中子辐照后，其测量值为5.5 pC/N，与已发表的文献值一致。这些结果为提高反应堆安全性以及通过在高辐射和高温环境下实现结构健康监测和无损检测来进一步理解辐射对材料的影响提供了潜力，因为已知这些环境会破坏典型的商用超声换能器。
