Ultrasonic detection method based on flexible capillary water column arrays coupling

• Published in: Ultrasonics 2024-04, Vol.139, p.107276-107276, Article 107276
• Main Authors: Wang, Kai, Song, Yini, Kang, Yihua, Guo, Yizhou, Ma, Hongbao, Wu, Shengping, Yang, Jin
• Format: Article
• Language: English
• Subjects: Flexible water column array; Microchannel guided acoustic field; Oblique surface scanning; Ultrasonic detection; Water coupling
• ISSN: 0041-624X; 1874-9968
• DOI: 10.1016/j.ultras.2024.107276

•A flexible water column array is applied for ultrasonic waveguide coupling.•Multimodal sound fields in complex flexible water columns are extracted and analyzed.•This coupling method has less acoustic attenuation (−20 %) within more reduction of area (−36 %).•The array coupling area influence the signal amplitude linearly.•Signal echoes are present when oblique angle below 20° by water column array. Conventional water immersion ultrasonic testing faces limitations due to factors such as environmental conditions, workpiece dimensions, corrosion, and resource wastage. Contact-based coupling methods, which employ coupling media or specific coupling structures, offer a convenient approach to coupling acoustic waves and reduce signal attenuation. However, these methods are time-sensitive and lack adaptability to uneven surfaces, particularly when dealing with workpieces featuring subtle undulations, resulting in significant signal decay. This paper presents an ultrasonic coupling method based on a flexible capillary water column array. By employing a stable and flexible water column array within the micro-channels as the coupling medium, stable contact-based transmission of ultrasonic signals is achieved. The influence of water column array unit dimensions and array structures is explored through theoretical analysis and experimentation, demonstrating lower energy attenuation compared to reductions in water column area. Notably, the tests revealed the method’s adaptability at oblique angles below 20°, which surpasses the performance of submerged detection at similar angles. This research presents an innovative and stable approach for contact-based ultrasonic coupling testing, particularly in scenarios involving dynamic contact scanning between ultrasonic waves and workpieces.