作者：何普, 赵纪元, 颜江涛

作者单位：西安交通大学机械工程学院, 陕西 西安 710049

关键词：无损检测;太赫兹波;热障涂层;厚度测量

摘要：

针对等离子喷涂工艺制备的热障涂层内部结构复杂、太赫兹波在热障涂层内传播衰减严重等问题，提出利用太赫兹波强度关系的热障涂层厚度测量方法，根据太赫兹波在热障涂层中的传播特性建立热障涂层太赫兹波传播模型，通过模型可以得到基于太赫兹检测信号的热障涂层厚度计算方法，然后根据菲涅尔定律和太赫兹检测信号回波能量关系建立折射率计算模型，提出使用热障涂层结构特征影响因子S修正利用太赫兹波强度关系的热障涂层厚度测量方法，并进行实验验证。研究结果表明，该方法所得结果与130 nm分辨率共聚焦显微镜测量结果具有良好的一致性，平均绝对误差不大于17.29 μm，平均相对误差不高于3.42%，能够准确测量热障涂层厚度。

Thermal barrier coating thickness measurement method using terahertz wave intensity relationship
HE Pu, ZHAO Jiyuan, YAN Jiangtao
School of Mechanical Engineering, Xi'an Jiaotong University, Xi'an 710049, China
Abstract: Aiming at the problems of complex internal structure of thermal barrier coatings made by plasma spraying and serious attenuation of terahertz wave propagation in thermal barrier coatings, a calculation method of thermal barrier coating thickness based on the relationship of terahertz wave intensity was proposed. Firstly, according to the propagation characteristics of terahertz waves in thermal barrier coatings, a terahertz wave propagation model of thermal barrier coatings was established, and the calculation method of thermal barrier coating thickness based on terahertz detection signals could be obtained through the model. Then, a refractive index calculation model was established based on Fresnel's law and the relationship between the echo energy of the terahertz detection signals. Finally, a thermal barrier coating thickness calculation method based on the THz wave intensity relationship using the influence factor S of the thermal barrier coating structure characteristic was proposed, and the experimental verification was carried out. The research results show that the results obtained by this method are in good agreement with the measurement results of 130 nm resolution confocal microscopy, the average absolute error is not more than 17.29 μm, and the average relative error is not more than 3.42%. The method can accurately measure the thickness of the thermal barrier coating.
Keywords: non-destructive testing;terahertz waves;thermal barrier coatings;thickness measurement
2023, 49(9):1-6  收稿日期: 2022-6-21;收到修改稿日期: 2022-9-19
基金项目: 国家自然科学基金项目(51975452)
作者简介: 何普（1996-），男，河北邯郸市人，硕士研究生，专业方向为太赫兹无损检测。
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