• CN：11-2187/TH
• ISSN：0577-6686

›› 2011, Vol. 47 ›› Issue (24): 1-7.

• 论文 •

### 线聚焦无镜头式聚偏氟乙烯超声探头的研制及V(f, z)分析法在表面波波速测量中的应用

1. 北京工业大学机械工程与应用电子技术学院;成功大学机械工程系
• 发布日期:2011-12-20

### Design, Fabrication of Line-focus Lens-less Polyvinylidene Fluoride Transducers and Applications on Measuring Surface Acoustic Waves withV(f, z) Analytical Method

HE Cunfu;LÜ Yan;SONG Guorong;WU Bin;LEE Yungchun

1. College of Mechanical Engineering and Applied Electronics Technology, Beijing University of Technology Department of Mechanical Engineering, Cheng Kung University
• Published:2011-12-20

Abstract: Line-focus-beam ultrasonic material property characterization system enables accurate measurements on the phase velocities of leaky surface acoustic waves(LSAW) or rayleigh-type leaky surface acoustic waves. But in view of the lens of the conventional acoustic microscopy is expensive and difficult to produce, new method of design and fabrication of two line-focus lens-less polyvinylidene fluoride(PVDF) transducers is presented for acoustic microscopy system utilizing a 40 m thick piezoelectric PVDF film to construct the active element. The transducers introduced here centre around 5 MHz and 11 MHz respectively. Different from high cost of equipments and measuring the oscillation period on an operation of tone-burst mode, an improved V(f, z) method based on tow-dimensional Fourier transform is developed for the broadband measurements. A defocusing system for measuring surface acoustic waves is established and a non-contact immersion experiment of a polished fused quartz is carried out. The LSAW velocity extracted by V(f, z) analytical technique is compared with the theoretical one and they both are in good agreement.