超薄覆层/基层复合结构界面联接特性低频超声多导波估计方法

Low Frequency Ultrasonic Multi-guided Wave Method for Estimating of the Inter- face Bonding Property of the Ultra-thin Coating/Substrate Composite

文章提出低频超声多导波方法估计超薄覆层 /基层层状复合结构界面联接特性。文中分析了超薄覆层 /基层界面处于刚性联接、滑移联接和完全脱层三种情况下多种超声导波的色散特性 ,提出了以色散曲线为依据的低频超声多导波界面特性估计方法 ,进一步分析了影响方法估计准确性的各种因素。结合超声泄露导波频域分析方法 ,文章采用超声耦合剂耦合方式和一对中心频率为2 MHz的宽带纵波换能器 ,获取了 h<0 .1λ,具有不同界面联接特性的超薄覆层 /基层层状复合结构样品的超声多导波色散曲线 ,并对界面联接状况进行了定量估计。实验结果与理论符合的非常好。

A low- frequency ultrasonic multi- guided wave method suitable for estimating the interface bonding property of the ultra- thin coating/ substrate composite is presented.The dispersion properties of the ultrasonic multi- guided waves in ultra- thin coating/ substrate composites under the conditions of perfect bond,kissing bond and complete misbond are analyzed,which is the criterion of the interface bonding estimation method. The factors thatinfluence the accuracy of the method are also analyzed. Using the ultrasound coupler and a pair of broadband longitudinal wave transducers with2 MHz center frequency,we achieve the ultrasonic multiguided wave dispersion curve of the ultra- thin coating/ substrate composite with h<0 .1λ and differentinterface proper- ties by employing the leaky guided wave frequency- domain analysis method. Reasonably good comparison be- tween the theory and experiment was observed.