相控阵超声后处理成像技术采用离线计算的方式对超声回波数据进行分析,实现缺陷的成像及评价,与基于实时成像的常规相控阵超声检测技术相比,成像更清晰,缺陷表征能力更强。近年来,相控阵超声后处理成像技术逐渐成为研究热点,国内外相关学者相继建立全聚焦成像、向量全聚焦成像、波数域成像和时间反转成像等一系列基于全矩阵数据的后处理成像算法,检测精度及缺陷表征尺寸极限取得了很大突破。为此,从全矩阵数据的基础理论出发,介绍基于虚拟聚焦思想和频域反演思想的相控阵超声后处理典型成像算法的基本原理、技术特点、研究进展及应用现状,总结当前发展存在的问题和不足,预测相控阵后处理成像技术的未来发展。
Ultrasonic phased array post-processing imaging techniques make testing and evaluation of defects by using off-line algorithm. Greater defect imaging and characterization abilities have been shown over traditional ultrasonic phased array on-line method. Recently researches on ultrasonic phased array post-processing imaging have been dramatically increased and a series of post-processing imaging methods using full matrix data, like total focusing method, vector total focusing method, wave number algorithm and time reversal imaging with multiple signal classification, have been established and shown significant breakthrough in imaging resolution and minimum detecting size. Starting from full matrix data, the different post-processing imaging techniques are reviewed, and their future development is predicted.