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NiCrAlY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 barrier coatings during preparation, the transient thermal response spectrum of NiCrAlY 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.