【摘要】 传统超声B扫描和C扫描成像方法不能满足复合材料的检测需求。简要介绍了超声特征扫描(F扫描)成像方法的原理、扫描系统的设计和聚焦探头的制作等。F扫描是以波形上升时间、下降时间、脉冲周期和频谱特性等波形特征或缺陷类型、形状和大小等缺陷特征为特征量进行信号提取和重构并最终成像的方法。试验样件为2 mm厚的复合层状薄板,在板中距上表面0.6和1.4 mm处的两层结合层中分别制作了三个最小直径为1.2 mm的分层缺陷。试验表明,设计的超声特征扫描系统可采用幅度成像、深度成像和底波成像方法成功检测出预制缺陷,并且可实现层析成像功能,还可用于层状薄板的密度和硬质合金的厚度成像,具有强大的功能和多种材料分析用途。更多还原

【Abstract】 Conventional ultrasonic imaging methods such as B-scan and C-scan couldn’t meet the requirements of composite inspection. A new ultrasonic imaging method, feature scan (F-scan) imaging, was introduced including its inspecting principle, scanning system design and focusing transducer manufacture and so on. In the method of F-scan imaging, ultrasonic waveform features (i.e. rising and falling time, pulse period and frequency spectrum) and defect features (i.e. the type, shape and size of defects) were taken as characteristic quantity to acquire and reconstruct the signals received, and finally to make imaging. The laminated composite thin plate with thickness of 2 mm was taken as testing sample, in which three lamination defects with diameter not less than  1.2 mm were made on the binding layers at 0.6 mm and 1.4 mm from the upper surface of the composite plate respectively. It was shown by experimental results that the prepared defects were successfully detected by the ultrasonic feature scanning system designed with various imaging modes (e.g. amplitude imaging, depth imaging and bottom wave imaging). The designed system had an additional function of computed tomography, and could also be used for the imaging of both the density of thin laminated plate and the thickness of hard alloys. Based on its special and effective function, ultrasonic feature scan imaging method would find wide application in material analysis.更多还原