基于小波分解的热波相位特征提取及喷涂层厚度评价  

Phase spectra extract of thermal wave with wavelet decomposition and coating thickness estimation

作　　者：郭伟[1] 董丽虹[1] 王海斗[1] 徐雅薇 徐滨士[1] 

机构地区：[1]装甲兵工程学院再制造技术重点实验室,北京100072

出　　处：《红外与激光工程》2017年第9期81-87,共7页Infrared and Laser Engineering

基　　金：国家自然科学基金(51675532;51535011)

摘　　要：针对热障涂层制备过程中的厚度评估问题,通过数值模拟手段研究了光脉冲激励下制备在镍基高温合金上不同厚度的Ni Cr Al Y涂层表面热波瞬态响应规律;在此基础上分析了表面热波相位特征随涂层厚度的变化规律,结果表明特定频率范围的热波相位特征与涂层厚度具有近似线性对应关系,但不同涂层厚度之间的相位差绝对值较小,不利于厚度定量评价;为提高不同厚度涂层之间的热波相位差,提出采用小波分解第二层细节系数对涂层表面热波进行重构,重构热波相位差比原始热波提高了约500倍,有利于提高涂层厚度评价的准确率;最后采用试验手段验证了模拟结果的准确性。Aiming at the thickness estimating problem of thermal battier coatings during preparation, the transient thermal response spectrum of NiCrA1Y coating on nickel-based superalloy was researched through numerical simulation method. Further more, the phase spectra of original thermal waves with different coating thickness was analysed, which suggested that the phase value and coating thickness comply with linear relationship in a special range of frequency. But the absolute phase D-value is too little to evaluate coating thickness in engineering application. So a method of wavelet decomposition was proposed to increase the phase D-value between different coating thickness, the 2nd level details coefficient was employed for thermal wave reconstruction, and the phase D-value of reconstructed thermal wave increase about more than 500 times, which is extremely conducive to raise the accuracy rate in coating thickness estimation. At last, the analog result was confirmed by experimental test.

关 键 词：热障涂层 厚度 红外热波检测 相位特征 小波分解 

分 类 号：TG115.28[金属学及工艺—物理冶金] V250.2[金属学及工艺—金属学]