Wu Kuo-Ting, Kobayashi Makiko, Jen Cheng-Kuei
Department of Electrical and Computer Engineering, McGill University, Montreal, QC, Canada.
IEEE Trans Ultrason Ferroelectr Freq Control. 2009 Jun;56(6):1218-24. doi: 10.1109/TUFFC.2009.1163.
Piezoelectric thick (>66 microm) films have been directly coated onto aluminum (Al) substrates using a sol-gel spray technique. With top electrode, these films serve as integrated ultrasonic transducers (IUT), which normally operate as thickness longitudinal wave transducers. When such IUT are located at the edges of the metallic plates, they can excite and detect symmetrical, antisymmetric and shear horizontal types of plate acoustic waves (PAW) using mode conversion methods. In 2 mm thick Al plates, 2 line defects of 1 mm width and 1 mm depth were clearly detected at temperatures up to 150 degrees C in pulse-echo mode. Results indicated that, for 2 mm thick aluminum plates, shear horizontal PAW were the best for the line defect detection. Also, the experimental results agree well with those obtained by a finite-difference-based method.
采用溶胶-凝胶喷涂技术已将压电厚膜（厚度大于66微米）直接涂覆在铝（Al）基板上。带有顶部电极时，这些薄膜可作为集成超声换能器（IUT），其通常作为厚度纵向波换能器工作。当此类IUT位于金属板边缘时，它们可以使用模式转换方法激发和检测对称、反对称和水平剪切类型的板声波（PAW）。在2毫米厚的铝板中，在高达150摄氏度的温度下，采用脉冲回波模式清晰地检测到了宽度和深度均为1毫米的2条线缺陷。结果表明，对于2毫米厚的铝板，水平剪切PAW最适合用于线缺陷检测。此外，实验结果与通过基于有限差分的方法获得的结果非常吻合。
