NDT & E Laboratory, Dalian University of Technology, Dalian 116085, China.
NDT & E Laboratory, Laser Institute of Shandong Academy of Sciences, Jinan 250014, China.
Ultrasonics. 2014 Apr;54(4):1005-9. doi: 10.1016/j.ultras.2013.11.012. Epub 2013 Dec 7.
The thermally grown oxide (TGO) growth at the interface of ceramic coating/bond coating in thermal barrier coatings (TBCs) was evaluated by ultrasonic reflection coefficient amplitude spectrum (URCAS). A theoretical analysis was performed about the influence of acoustic impedance match relationship between the ceramic coating and its adjacent media on URCAS. The immersion ultrasonic narrow pulse echo method was carried out on the TBC specimen before and after oxidation under 1050°C×1h for 15cycles. The resonant peaks of URCAS obtained before and after oxidation showed that TGO which generated between the ceramic coating and bond coating due to the oxidation, changed the acoustic impedance match between the ceramic coating and its adjacent media. This method is able to nondestructively characterize the generation of TGO in TBCs, and is important to practical engineering application.
采用超声反射系数幅度谱（URCAS）评价热障涂层（TBC）中陶瓷涂层/粘结涂层界面处热生长氧化物（TGO）的生长情况。对陶瓷涂层与其相邻介质之间的声阻抗匹配关系对 URCAS 的影响进行了理论分析。在 1050°C×1h 条件下进行 15 个循环氧化后，对 TBC 试样进行了浸超声窄脉冲回波法测量。氧化前后 URCAS 的共振峰表明，由于氧化在陶瓷涂层和粘结涂层之间产生的 TGO 改变了陶瓷涂层与其相邻介质之间的声阻抗匹配。该方法能够对 TBC 中 TGO 的产生进行无损表征，对实际工程应用具有重要意义。
