等厚铝/铝黏接结构的超声脉冲反射信号

Ultrasonic pulse reflection signal of aluminum/aluminum bonded structures with equal thickness

针对黏接结构存在缺陷的问题,对等厚铝/铝黏接结构的超声界面模型及传播路径进行分析,得到黏接良好部位与黏接不良部位的脉冲反射信号,构造模拟回波信号。改变黏接良好部位及不良部位的黏接层厚度,并观察第5次回波信号幅值。结果表明:黏接不良部位第5次回波幅值显著低于黏接良好区域的幅值,且该回波幅值不受黏接层厚度以及残留粘胶厚度的影响,故可将第5次回波幅值作为判据来判断黏接结构是否存在黏接不良缺陷。

Aiming at the problem of defects in the bonding structure,the ultrasonic interface model and propagation path of the equal-thickness aluminum/aluminum bonding structure were analyzed.The pulse reflection signals of the bonded parts and the poorly bonded parts were obtained,and the simulated echo signals were constructed.The thickness of the bonding layer between the bonded and defective parts was changed and the amplitude of the fifth echo signal was correspondingly observed.The results show that the amplitude of the fifth echo of the poorly bonded part is significantly lower than that of the well-bonded area,and is not affected by the thickness of the bonding layer and the residual adhesive thickness.The fifth echo amplitude can be used as a criterion to judge whether there is a defect of poor adhesion in the bonding structure.